Last updated 2014April 16
(Please be aware that some of the links on this page may no longer be active. Inactive ones so identified have been removed.
2013 October 31: Observing Campaign: November Appulse of three Minor Planets
During November 9-12, three asteroids (228 Agathe, 2043 Ortutay and 6426 Komurotoru) happen to pass close to one another as seen in the constellation of Taurus. In reality these objects are very well spaced apart: they just happen to lie close together when seen along our line of sight. You therefore have an opportunity to simultaneously observe all three bodies in the same CCD field of view. The best nights are Nov 10/11 and Nov 11/12 when they will all be contained within a patch of sky some 22′ across. The earlier night will be best of all as the Moon will be further away and a little fainter then. The apparition will be favourable as the field will be relatively high in the sky throughout most of the night – visible from 2000UT-0600UT as seen from the UK.
The Plan: We already know the rotation period of 228 Agathe (6.5 hours) but do not know the periods for the other two objects. If several observers take time-series of these minor planets, we may have enough data to solve the two unknown rotation rates. Another, more novel approach would be to try and detect any significant colour changes (by measuring the colour of each expressed relative to the others) during the course of a night. The minimum requirement would be to take alternative series of images (say 10 at a time) through two different filters (e.g. using V and R filters) for several hours. Very few asteroids are known to exhibit colour variation as they rotate. It would be good to discover some new ones!
Graham Relf has posted a full chart depicting the appulse here on the Computing Section webpages. All three asteroids are 14th magnitude so you’ll need a fairly large scope to participate effectively. For more details, or if you are planning to attempt observations then do contact the Director. Here’s a plot of their motion between November 5-20 – the grid shown is about 1 degree square:
2013 October 02: Video Astrometry – A new observing opportunity
Section member Alex Pratt is a keen occultation observer for which he uses an integrating Mintron video camera and GPS time-inserter to record asteroidal and lunar occultations of stars. Recently he used his observing equipment to record the passage of some fast-moving asteroids, notably 1998 QE2 and 2012 DA14. Exposure times as short as 0.04 sec per frame can be employed yet, using relatively wide-field optics, several field stars were recorded in addition to the asteroids and so it was possible to measure the astrometric positions of the movers with high precision thanks to the very accurate time stamp on each frame. What made all the difference was the availability of the software TANGRA 1.4 written by Hristo Pavlov with which it is possible to analyse the frames for both astrometry and photometry.
Thankfully, Alex has compiled A Guide to Video Astrometry for anyone wishing to try using a video camera for measuring the positions of very fast-moving objects (VFMOs). This 2.2 Mb PDF is a nice step-by-step ‘How-To’ guide which sets out all aspects of the process involved and includes relevant weblinks. His results proved good to an accuracy of about 0.2 arcseconds even for an object moving at a rate of some 10 arcsec per second of time! He even used the equipment to measure the positions of some main-belt asteroids, which after submitting these to the Minor Planet Center enabled him to receive his own IAU Observatory Code (Z92). Great work, Alex!
2013 Feb 15: Record close approach of 2012 DA14
Unlike the bolide seen and felt in the Urals earlier the same day, the dramatic passage of near-Earth asteroid 2012 DA14 has been forecast one year in advance thanks to it having been discovered last February by amateur astronomers at the La Sagra Sky Survey in Spain (MPC Code J75). Today 2012 DA14 will approach to within about 27,600 km of the Earth’s surface at about 19:24 UT whilst travelling at 7.8 km/sec. During the last week many more observatories have imaged the object, in particular; Mount John Observatory, New Zealand (MPC Code 474); the 2.0-m Faulkes Telescope South (which is now back in business after last month’s devastating bushfires which badly affected Siding Spring and the surrounding community) (MPC Code E10); as well as the new LCOGT 1.0-m ‘B’ telescope at Cerro Tololo, Chile (MPC Code W86). Just 7 hours before closest approach (bca), Dave Herald of Murrumbateman, Australia has captured an image of the intruder, which appears to show the object some 0.5 magnitudes brighter than expected. Dave’s latest image was obtained 4 hours bca.
Reaching 7th magnitude, it is the brightest-ever NEO to be observed approaching the vicinity of our planet (<0.1 AU) and visible with modest telescopic aid, e.g. binoculars. 2012 DA14 will pass about 14x closer to the Earth than our companion Moon. To put this in perspective, scientists at NASA’s Near-Earth Object Program Office in Pasadena, California estimate that an asteroid the size of 2012 DA14 flies this close every 40 years on average and that one will impact Earth, on average, about once in every 1,200 years
Nick James has undertaken a live webcast of the 2012 DA14 close-approach periodically updating live images from a small telescope with a field of view of around 1 degree. as available here:
Unfortunately cloudy skies have dogged the attempt with just the occasional star or two being visible from time to time. The animation has generally shown only passing clouds
If you wish to observe the interloper yourself then, depending on your location, you are advised to obtain your local topocentric RA and Dec coordinates from websites such as can be found at:
Remember to enter either your latitude and longitude, or the MPC Code of a nearby observatory
I have prepared a chart for the interval 19:50-21:00 UT in anticipation of its visibility soonafter it rises near the eastern horizon as seen from the southern UK.
A second chart covers the later period, 21:00-01:00 UT on the evening of Feb 15/16. Full observing details and a 5-minute ephemerides for UK observers are also available here. The charts are probably useable by all UK observers since the object will be conspicuous owing to the fact that it will be seen to be moving in real time. Look with binoculars or a small telescope within a degree or so of the predicted position at any given time and it should ‘jump out’ as a moving star.
Here’s a challenge for observers: pick a site where you have a low eastern horizon and try and image the fast-mover as soon as possible after it rises. The further east your location the better chance you’ll have. There’ll be a prize for anyone observing from the UK who records the earliest image of 2012 DA14 ! Please report your observations to the ARPS Director at the following e-mail address: firstname.lastname@example.org
NASA have set up a very informative webpage with useful FAQs, orbit diagrams and some videos of interviews, etc
2013 Feb 15: Bolide over the Urals
A small asteroid entered the Earth’s atmosphere about 3:20 UT on 2013 Feb 15 over the Urals in Russia, exploding with the energy equivalent in the range of 0.1-0.3 megaton TNT, which makes it the most energetic such event since the Tunguska exposion of 1908 according to Dr Peter Brown of the University of Western Ontario . The object was reported to have travelled from north-east to south-west and so there can be no possible association with 2012 DA14 since otherwise it would have to have approached from the south direction and headed almost directly northwards. These two objects are therefore totally unrelated. See for example this collection of videos and still photos.
PLANOCCULT/H. Pavlov. In March this year the asteroid 2009 DD45 come very close to the Earth and became bright enough to be observed by amateurs. Back then John Broughton suggested that video astrometry may show better results than CCD astrometry because of the better time resolution. In fact Dave Herald and myself successfully observed the asteroid from down under and the reported astrometry was with a better accuracy than some major observatories.
As a result a guide to video astrometry was put together and made available. It can be downloaded from the MPC web site: http://www.cfa.harvard.edu/iau/info/VideoAstrometry.pdf
Now there is another NEO which is coming close to us. It will not be as fast as DD45 but will be almost as bright. On 9 Feb 2010 the asteroid 2009 UN3 will come as close as 0.037 UA to the Earth and will be moving with 50″/min at 12.3 Mag. This will make it a very interesting target for those that want to try video astrometry this time around.
Knowing the position of the target is essential and to get an accurate ephemeris you will need to use the MPC ephemeris service: http://www.cfa.harvard.edu/iau/MPEph/MPEph.html
From 2009 DD45, I remember that finding the target was the most difficult part of the observation. You will want to have available the position of the object every 15 min. In case you loose it you can go to the next expected position and wait for it to come.
2009 UN3 will be an excellent opportunity for occultationists with integrating video cameras or bigger telescopes to try another area in which amateurs can make a difference. So don’t wait but read the video astrometry guide and get ready to observe. And remember for astrometry you need as many stars as you can get in the FOV and the target does not have to be in the center.
MPML /E.P. Grondine. The announced NASA budget has added $16 million each year to the NEO search, bringing the amount to $20 million per year. While this is a substantial improvement, it is still short of the $50 million per year option of the NRC.
MPML /F. Pilcher. My colleague Roger Harvey wishes to observe visually 878 Mildred, the faintest of the first 1000 asteroids to be numbered, and the only one of this set which he has not seen in a career spanning more than 30 years. Minor Planet 878 Mildred will be observable from approximately 2010 July 30 – Aug. 15 near RA 20h30m, Dec. -15 degrees, magnitude 16.6 This will be its brightest for several years. If anybody knows of a place in North America where he can obtain time on a telescope large enough to reach this magnitude through a visual eyepiece, please correspond with this author. Thanks. Frederick Pilcher. (Some Achievement – RD)
MPML /R.Baalke – JPL. NASA’s Wide-field Infrared Survey Explorer, or WISE, has spotted its first never-before-seen near-Earth asteroid, the first of hundreds it is expected to find during its mission to map the whole sky in infrared light. There is no danger of the newly discovered asteroid hitting Earth. http://www.jpl.nasa.gov/wise/newsfeatures.cfm?release=2459
The near-Earth object, designated 2010 AB78, was discovered by WISE Jan. 12. The mission’s sophisticated software picked out the moving object against a background of stationary stars. As WISE circled Earth, scanning the sky above, it observed the asteroid several times during a period of one-and-a-half days before the object moved beyond its view. Researchers then used the University of Hawaii’s 2.2-meter (88-inch) visible-light telescope near the summit of Mauna Kea to follow up and confirm the discovery.
The asteroid is currently about 158 million kilometers (98 million miles) from Earth. It is estimated to be roughly 1 kilometer (0.6 miles) in diameter and circles the sun in an elliptical orbit tilted to the
plane of our solar system. The object comes as close to the sun as Earth, but because of its tilted orbit, it will not pass very close to Earth for many centuries. This asteroid does not pose any foreseeable
impact threat to Earth, but scientists will continue to monitor it.
Near-Earth objects are asteroids and comets with orbits that pass relatively close to Earth’s path around the sun. In extremely rare cases of an impact, the objects may cause damage to Earth’s surface. An
asteroid about 10 kilometers (6 miles) wide is thought to have plunged into our planet 65 million years ago, triggering a global disaster and killing off the dinosaurs.
Additional asteroid and comet detections will continue to come from WISE. The observations will be automatically sent to the clearinghouse for solar system bodies, the Minor Planet Center in Cambridge, Mass., for comparison against the known catalog of solar system objects. A community of professional and amateur astronomers will provide follow-up observations, establishing firm orbits for the previously unseen objects.
“This is just the beginning,” said Ned Wright, the mission’s principal investigator from UCLA. “We’ve got a fire hose of data pouring down from space.”
On Jan. 14, the WISE mission began its official survey of the entire sky in infrared light, one month after it rocketed into a polar orbit around Earth from Vandenberg Air Force Base in California. By casting a wide net, the mission will catch all sorts of cosmic objects, from asteroids in our own solar system to galaxies billions of light-years away. Its data will serve as a cosmic treasure map, pointing astronomers and telescopes, such as NASA’s Spitzer Space Telescope and the upcoming James Webb Space Telescope, to the most interesting finds.
WISE is expected to find about 100,000 previously unknown asteroids in our main asteroid belt, a rocky ring of debris between the orbits of Mars and Jupiter. It will also spot hundreds of previously unseen near-Earth objects.
By observing infrared light, WISE will reveal the darkest members of the near-Earth object population — those that don’t reflect much visible light. The mission will contribute important information about asteroid and comet sizes. Visible-light estimates of an asteroid’s size can be deceiving, because a small, light-colored space rock can look the same as a big, dark one. In infrared, however, a big dark rock will give off more of a thermal, or infrared glow, and reveal its true size. This size information will give researchers a better estimate of how often Earth can expect potentially devastating impacts.
“We are thrilled to have found our first new near-Earth object,” said Amy Mainzer of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Mainzer is the principal investigator of NEOWISE, a program to mine the collected WISE data for new solar system objects. “Many programs are searching for near-Earth objects using visible light, but some asteroids are dark, like pavement, and don’t reflect a lot of sunlight. But like a parking lot, the dark objects heat up and emit infrared light that WISE can see.”
“It is great to receive the first of many anticipated near-Earth object discoveries by the WISE system,” said Don Yeomans, manager of NASA’s Near-Earth Object Program Office at JPL. “Analysis of the WISE data will go a long way toward understanding the true nature of this population.” (This created a certain amount of what might be called ‘excitement’ on the MPML – RD)
A new report from the National Research Council lays out options NASA could follow to detect more near-Earth objects (NEOs) — asteroids and comets that could pose a hazard if they cross Earth’s orbit. The report says the $4 million the U.S. spends annually to search for NEOs is insufficient to meet a congressionally mandated requirement to detect NEOs that could threaten Earth.
Congress mandated in 2005 that NASA discover 90 percent of NEOs whose diameter is 140 meters or greater by 2020, and asked the National Research Council in 2008 to form a committee to determine the optimum approach to doing so. In an interim report released last year, the committee concluded that it was impossible for NASA to meet that goal, since Congress has not appropriated new funds for the survey nor has the administration asked for them.
In its final report, the committee lays out two approaches that would allow NASA to complete its goal soon after the 2020 deadline; the approach chosen would depend on the priority policymakers attach to spotting NEOs. If finishing NASA’s survey as close as possible to the original 2020 deadline is considered most important, a mission using a space-based telescope conducted in concert with observations from a suitable ground-based telescope is the best approach, the report says. If conserving costs is deemed most important, the use of a ground-based telescope only is preferable.
The report also recommends that NASA monitor for smaller objects — those down to 30 to 50 meters in diameter — which recent research suggests can be highly destructive. However, the report stresses that searching for smaller objects should not interfere with first fulfilling the mandate from Congress. Beyond completion of that mandate, the report notes the need for constant vigilance in monitoring the skies, so as to detect all dangerous NEOs. In addition, the nation should undertake a peer-reviewed research program to better investigate the many unknown aspects connected with detecting NEOs and countering those that could be a threat. The U.S. should also take the lead in organizing an international entity to develop a detailed plan for dealing with hazards from these objects.
In addition, the report recommends that immediate action be taken to ensure the continued operation of the Arecibo Observatory in Puerto Rico. NASA and NSF should support a vigorous program of NEO observations at Arecibo, and NASA should also support such a program at the Goldstone Deep Space Communications Complex. Although these facilities cannot discover NEOs, they play an important role in accurately determining the orbits and characterizing the properties of NEOs within radar range.
The Scope of the Hazard
Near-Earth objects are asteroids and comets that orbit the Sun and approach or cross Earth’s orbit. An asteroid or comet about 10 kilometers in diameter struck the Yucatan peninsula 65 million years ago and caused global devastation, probably wiping out large numbers of plant and animal species including the dinosaurs. Objects as large as this one strike Earth only about once every 100 million years on average, the report notes. NASA has been highly successful at detecting and tracking objects 1 kilometer in diameter or larger, and continues to search for these large objects. Objects down to sizes of about 140 meters in diameter — which NASA has been mandated to survey for — would cause regional damage; such impacts happen on average every 30,000 years, the report says.
While impacts by large NEOs are rare, a single impact could inflict extreme damage, raising the classic problem of how to confront a possibility that is both very rare and very important. Far more likely are those impacts that cause only moderate damage and few fatalities. Conducting surveys for NEOs and detailed studies of ways to mitigate collisions is best viewed as a form of insurance, the report says. How much to spend on these insurance premiums is a decision that must be made by the nation’s policymakers.
The report also examines what is known about methods to defend against NEOs. These methods are new and still immature. No single approach is effective for the full range of near-Earth objects, the committee concluded. But with sufficient warning, a suite of four types of mitigation is adequate to meet the threat from all NEOs, except the most energetic ones.
* Civil defense (evacuation, sheltering in place, providing emergency infrastructure) is a cost-effective mitigation measure for saving lives from the smallest NEO impact events and is a necessary part of mitigation for larger events.
* “Slow push” or “slow pull” methods use a spacecraft to exert force on the target object to gradually change its orbit to avoid collision with the Earth. This technique is practical only for small NEOs (tens of meters to roughly 100 meters in diameter) or possibly for medium-sized objects (hundreds of meters), but would likely require decades of warning. Of the slow push/pull techniques, the gravity tractor appears to be by far the closest to technological readiness.
* Kinetic methods, which fly a spacecraft into the NEO to change its orbit, could defend against moderately sized objects (many hundreds of meters to 1 kilometer in diameter), but also may require decades of warning time.
* Nuclear explosions are the only current, practical means for dealing with large NEOs (diameters greater than 1 kilometer) or as a backup for smaller ones if other methods were to fail.
Although all of these methods are conceptually valid, none is now ready to implement on short notice, the report says. Civil defense and kinetic impactors are probably the closest to readiness, but even these require additional study prior to reliance on them.
Given the significant unknowns about many aspects of the threat and its mitigation, the report recommends that the U.S. start a peer-reviewed, targeted research program on the hazards posed by NEOs, and how to deal with them. Because this is a policy-driven, applied research program, it should not be in competition with basic scientific research programs or be funded from them, the report adds.
The study was sponsored by NASA at the request of Congress. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies. They are private, nonprofit institutions that provide science, technology, and health policy advice under a congressional charter. The Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering. A committee roster follows.
Copies of “Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies” are available from the National Academies Press, telephone +1 202-334-3313 or 1-800-624-6242, or on the Internet at http://www.nap.edu/catalog.php?record_id=12842.
MPML /R. Kowalski. A short video interview with Mike Drake, LPL Director and mission PI and Dante Lauretta, Deputy PI about the proposed OSIRIS-Rex mission to asteroid 1999 RQ36 http://uanews.org/node/29491
MPML /R. Baalke. NASA has selected three proposals as candidates for the agency’s next space venture to another celestial body in our solar system. The final project selected in mid-2011 may provide a better understanding of Earth’s formation or perhaps the origin of life on our planet.
The proposed missions would probe the atmosphere and crust of Venus; return a piece of a near-Earth asteroid for analysis; or drop a robotic lander into a basin at the moon’s south pole to return lunar
rocks back to Earth for study.
NASA will select one proposal for full development after detailed mission concept studies are completed and reviewed. The studies begin during 2010, and the selected mission must be ready for launch no
later than Dec. 30, 2018. Mission cost, excluding the launch vehicle, is limited to $650 million.
“These are projects that inspire and excite young scientists, engineers and the public,” said Ed Weiler, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. “These three proposals provide the best science value among eight submitted to NASA this year.”
Each proposal team initially will receive approximately $3.3 million in 2010 to conduct a 12-month mission concept study that focuses on implementation feasibility, cost, management and technical plans.
Studies also will include plans for educational outreach and small business opportunities.
The selected proposals are: The Surface and Atmosphere Geochemical Explorer, or SAGE, mission to Venus would release a probe to descend through the planet’s atmosphere. During descent, instruments would conduct extensive measurements of the atmosphere’s composition and obtain meteorological data. The probe then would land on the surface of Venus, where its abrading tool would expose both a weathered and a pristine surface area to measure its composition and mineralogy. Scientists hope to understand the origin of Venus and why it is so different from Earth. Larry Esposito of the University of Colorado in Boulder, is the principal investigator.
The Origins Spectral Interpretation Resource Identification Security Regolith Explorer spacecraft, called Osiris-Rex, would rendezvous and orbit a primitive asteroid. After extensive measurements, instruments would collect more than two ounces of material from the asteriod’s surface for return to Earth. The returned samples would help scientists better understand and answer long-held questions about the formation of our solar system and the origin of complex molecules necessary for life. Michael Drake, of the University of Arizona in Tucson, is the principal investigator.
MoonRise: Lunar South Pole-Aitken Basin Sample Return Mission would place a lander in a broad basin near the moon’s south pole and return approximately two pounds of lunar materials for study. This region of the lunar surface is believed to harbor rocks excavated from the moon’s mantle. The samples would provide new insight into the early history of the Earth-moon system. Bradley Jolliff, of Washington University in St. Louis, is the principal investigator.
The proposals were submitted to NASA on July 31, 2009, in response to the New Frontiers Program 2009 Announcement of Opportunity. New Frontiers seeks to explore the solar system with frequent,
medium-class spacecraft missions that will conduct high-quality, focused scientific investigations designed to enhance understanding of the solar system.
The final selection will become the third mission in the program. New Horizons, NASA’s first New Frontiers mission, launched in 2006, will fly by the Pluto-Charon system in 2014 then target another Kuiper Belt object for study. The second mission, called Juno, is designed to orbit Jupiter from pole to pole for the first time, conducting an in-depth study of the giant planet’s atmosphere and interior. It is
slated for launch in August 2011. For more information about the New Frontiers Program, visit: http://newfrontiers.nasa.gov
MPML /R. Baalke. Close-up images of asteroid (2867) Steins, obtained with the OSIRIS cameras on Rosetta, have provided extensive new measurements of the physical properties of this main-belt asteroid. Steins is revealed to be a loosely-bound ‘rubble pile’ whose diamond shape has been honed by the YORP effect. This is the first time this effect has been seen in a main-belt asteroid. The results are reported by H. Uwe Keller and colleagues in the 8 January issue of Science magazine.
Most models of Solar System formation posit that the planets formed from the collision and eventual coalescence of planetesimals. Beyond the orbit of Mars, the gravitational perturbation of the giant planet Jupiter prevented the formation of a planet-sized body by disrupting the orbits of many of these planetesimals. The remaining bodies, some of them several hundred kilometres in size, have undergone frequent collisions since this time and today mostly occupy the asteroid belt between the orbits of Mars and Jupiter. Asteroids are of interest for understanding the formation process of our Solar System because they carry information about the nature and composition of the Solar System at an early stage of its formation. Asteroid (2867) Steins, an E-type asteroid, is a rare type of solar system body. Only a few tens of these asteroids have been detected.
In the results published in the 8 January issue of Science, H. Uwe Keller and colleagues report on observations of asteroid Steins obtained during the Rosetta flyby of 5 September 2008. This is the first time
that a close-up view of an E-type asteroid has been obtained. The closest approach to the asteroid was at 18:38:20 UTC at a distance of 803 km. About 60 per cent of the surface was resolved during the flyby providing a unique set of images from which a number of important physical properties can be inferred.
Little was known about asteroid (2867) Steins when it was chosen early in 2004 as one of the targets for a close flyby during the Rosetta mission. At the time, it was classified as an E-type asteroid on the
basis of its visual and near-infrared spectrum and its high albedo. Later, ground-based observations estimated a diameter of approximately 4.6 km and determined a rotation period of about 6 hours.
The new OSIRIS images show Steins to be an oblate body, resembling a brilliant cut diamond, with dimensions of 6.67x 5.81 x 4.47 kmÂ³. Its surface is mostly covered with shallow craters with some of the larger craters being pitted with smaller ones. Analysis of the impact craters reveals a deficit of small craters (those with diameter less than 0.5 km) which Keller and his colleagues attribute to surface reshaping as a result of the Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect (see footnote). The effect would have caused landslides which filled-in the smaller craters. This is the first time that the YORP effect has been seen in a main-belt asteroid.
Two remarkable features are clearly visible in the images obtained near closest approach: a large, 2.1 km diameter crater located at the south pole, and a chain of pits which extend northwards from this crater. Taken together these features suggest that Steins was subject to a big impact which created the large crater and caused fracturing of the asteroid body resulting in it having a rubble pile structure. This type of loosely-bound structure is also consistent with the YORP effect hypothesis.
Detailed study of the OSIRIS images has also allowed Keller and his colleagues to confirm the nature of Steins as an E-type asteroid – the albedo and spectral characteristics are consistent with this
classification – and to demonstrate that there is no measurable surface colour variation, which points to a homogeneous composition.
The view of Steins obtained by OSIRIS during the September 2008 flyby with Rosetta has provided scientists with the first detailed characterisation of this rare type of solar system body.
The results are reported in “E-type asteroid (2867) Steins as Imaged by OSIRIS on board Rosetta” by H. U. Keller, C. Barbieri, D. Koschny, P. Lamy, H. Rickman, R. Rodrigo, H. Sierks, M. F. Aâ€™Hearn, F. Angrilli, M. A. Barucci, J.-L. Bertaux, G. Cremonese, V. Da Deppo, B. Davidsson, M. De Cecco, S. Debei, S. Fornasier, M. Fulle, O. Groussin, P. J. Gutierrez, S. F. Hviid, W.-H. Ip, L. Jorda, J. Knollenberg, J. R. Kramm, E. KÃ¼hrt, M. KÃ¼ppers, L.-M. Lara, M. Lazzarin, J. Lopez Moreno, F. Marzari, H. Michalik, G. Naletto, L. Sabau, N. Thomas, K.-P. Wenzel, I. Bertini, S. Besse, F. Ferri, M. Kaasalainen, S. Lowry, S. Marchi, S. Mottola, W. Sabolo, S. E. SchrÃder, S. Spjuth, and P. Vernazza, Science, Vol. 327. no. 5962, pp. 190 â€“ 193, 8 January 2010. DOI: 10.1126/science.1179559
Footnote: The YORP effect is a phenomenon that occurs when photons from the Sun are absorbed by a body and reradiated as infrared emission which carries off momentum as well as heat. The loss of momentum causes a change in the rotation rate of a small body such as an asteroid. The resulting high spin rate of asteroid Steins could have caused material to migrate towards the equator of the asteroid resulting in the distinctive conical shape.
MPML /D. Herald (extract from post). The clear message is that at the accuracy we are working at with asteroidal occultations (0.01″ or
better) the accuracy of UCAC3 is generally either better than, or the same as, UCAC2.
MPML /R. Murray. http://au.arxiv.org/abs/astro-ph/0203152 Exotic meteoritic phenomena: The Tunguska event and anomalous low altitude fireballs — manifestations of the mirror world? R. Foot, T. L. Yoon (Submitted on 11 Mar 2002 (v1), last revised 10 May 2002 (this version, v5)
There are a number of very puzzling meteoritic events including (a) The Tunguska event. It is the only known example of a low altitude atmospheric explosion. It is also the largest recorded event. Remarkably no fragments or significant chemical traces have ever been recovered.(b) Anomalous low altitude fireballs which (in some cases) have been observed to hit the ground.
The absence of fragments is particularly striking in these cases, but this is not the only reason they are anomalous. On the other hand, there is strong evidence that most of our galaxy is made
from exotic dark material – `dark matter’. Mirror matter is one well motivated dark matter candidate, since it is dark and stable and it is required to exist if particle interactions are mirror symmetric.
If mirror matter is the dark matter, then some amount must exist in our solar system. We demonstrate that the mirror matter theory allows for a simple explanation for the puzzling meteoritic events [both (a) and (b)] if they are due to mirror matter space-bodies. A direct consequence of this explanation is that mirror matter fragments should exist in (or on) the ground at various impact sites. The properties of this potentially recoverable material depend importantly on the sign of the photon-mirror photon kinetic mixing parameter, “epsilon”. We argue that the broad characteristics of the anomalous events suggests that “epsilon” is probably negative. Strategies for detecting mirror matter in the ground are discussed.
MPML /D. Herald. The 2010 Jan 1 issue of the Journal of Double Star observations has now been published. It is at: http://www.jdso.org/ This issue contains a paper detailing double star discoveries made in asteroidal occultations up to the end of 2008 (covering a period of about 35 years). It also includes an explanation of the method of analysis (for future reference), including situations where the solution is ambiguous. In addition the paper contains the names of all observes associated with each of the 23 events – with there being well over 100 names listed.
There are several papers that have been submitted and accepted, but not included in this issue for reasons of space. I urge anyone who has responsibility for drafting papers for the JDSO to do thdrafting sooner rather than later, to avoid lengthy delays until actual publication of the paper.
MPML /C.Bell. The IAU Minor Planet Center Guide to Minor Body Astrometry was updated again on Dec 18, 2009. It was updated earlier on Dec 11 as noted by J05 P. Birtwhistle.
http://www.cfa.harvard.edu//iau/info/Astrometry.html The link to the Dec 18 change points to “When should I use a discovery asterisk?” The link to the Dec 11 change points to “What about coverage on a single night?”
MPML /P. Birtwhistle. For further clarification on the use of “K” for astrometry obtained from stacked images (and also the submission of single positions) see the Guide to Minor Body Astrometry, updated Dec. 11th here:
MPML / F. Tozzi, H. Raab. Astrometrica could not only insert automatically the “K” when/if astrometry is from stacked images (Herbert said that he will implement this), but also close to the text box were we have to enter the object designation he could also present a listbox with all the alphabetic publishable notes. Herbert Raab replied; That’s exactly what I intend to do. It will take a few days,
though, as I am currently moving all my software to a new PC, and it will take me some time before everything is up and running.
The default for stacked images will certainly be ‘K’, but if the observer decides that any other flag is more important in a particular case, he or she can change that flag.
Personally, I see no problem with flagging stacked images. A lot of people do excellent work using stacked images, and I see no reason why that flag will depreciate their work. In case that there is some problem with an observation, it might be useful to know that it came from a stack.
The ultimate solution would probably be the new MPC format. That would allow for multiple flags, and additional information ( SNR , error estimate) that would certainly tell more about a
observation than a simple flag.
MPML /R.Kowalski. Russia may send spacecraft to knock away asteroid. http://www.usatoday.com/tech/science/space/2009-12-30-russia-asteroid_N.htm
MPML /D. Fischer, R. Kowalski. Ten years ago I discussed such matters with a leading Aussie geologist and crater expert – who warned me that these ‘dreamtime’ stories are pretty secret stuff and that
Aborigines sometimes made up new stories when talking to researchers to fit their expectations. In particular I was told that the *real* dreamtime stories about impact craters usually don’t have cosmic connections whatsoever, e.g. in one case (Wolf Creek?) the story is that a giant snake came out of the ground, causing the hole with the raised rim. There were signs at Gosses Bluff back then telling
alleged dreamtime stories that do include an impact, but in the light of that geologist’s experience that may be doubtful. Actual literature references on that complex would be appreciated, actually. Image at;
MPML /R. Kowalski. My paper entitled “Solar-Radiation Heating Effects on 3200 Phaethon” was finally published in the latest issue of PASJ, as follows,
http://pasj.asj.or.jp/v61/n6/610621/610621.pdf of which PDF file is freely downloadable now. Katsu OHTSUKA
MPML /B. Warner. Issue 37-1 of the Minor Planet Bulletin (Jan-Mar 2010) is now available as a free PDF download at: http://www.minorplanetobserver.com/mpb/default.htm Other recent issues are also available on that page.
MPML/R.Stoss. SkyMapper is among the first of a new breed of surveying telescopes which are able to scan the nighttime skies more quickly and deeper than ever before. The SkyMapper telescope will provide a deep digital map of the southern sky which will allow astronomers to study everything from nearby objects such as asteroids in our solar system to the most distant objects in the universe called quasars. The data taken by the SkyMapper
telescope will be shared with astronomers around the world via the Virtual Observatory initiative, so that every possible use can be made of this resource.
MPML/A. Milani. A new book “Theory of orbit determination” by Milani & Gronchi, 392 pages, has been published by Cambridge University Press. If purchasing this book support the BAA by accessing Amazon via the BAA Journal webpage.
MPML/M. Clark. “An unusual meteorite with an interesting orbit has been tracked to the ground using a photographic observatory that records time-lapse images of fireballs traveling across the sky.
NASA/JPL NEO Program. A newly discovered asteroid designated 2009 VA, which is only about 7 meters in size, passed about 2 Earth radii (14,000 km) from the Earth’s surface Nov. 6 at around 16:30 EST. This is the third-closest known (non-impacting) Earth approach on record for a cataloged asteroid. The two closer approaches include the 1-meter sized asteroid 2008 TS26, which passed within 6,150 km of the Earth’s surface on October 9, 2008, and the 7-meter sized asteroid 2004 FU162 that passed within 6,535 km on March 31, 2004. On average, objects the size of 2009 VA pass this close about twice per year and impact Earth about once every 5 years.
MPML/S. Degenhardt. Preliminary results of the occultation on Nov 21, 2009 by the potential binary asteroid (234) – view a 4 minute video
MPML/R.Stoss. MINOR PLANET CENTER EDITORIAL NOTICE. (Guidelines for submitting observations to the MPC)
General Observing Practices
The number of observers submitting astrometric observations to the MPC has risen rather dramatically in the past year. This has been accompanied by a rather worrying and troublesome increase in poor observing practice, with many sub-standard quality observations reported to the MPC.
Observers should strive to provide the best quality observations to the MPC. Poor quality observations cause the MPC significant extra work and reflect badly on the observer.
Some good practice advice follows:
* Observe each object at least three times over the course of an hour or so on each night. If the object is a known object, this can be relaxed to 30 minutes or more, as long as the motion of the object in that period is significant.
* Provide two nights of observation for “new” objects, obtaining three to six observations on each night, with at least one hour of coverage on each night.
* If you have a suspected new NEO, more than six observations may be useful if they are obtained over the course of several hours.
* In following-up interesting objects, provide good coverage of at least one hour.
* Never, under any circumstance, provide a single, isolated observation on a single night. A single observation shows no evidence of motion and there is no guarantee that the observer has not measured an image defect, a star or a variable object (star, nova or supernova).
* Stacked observations should always be marked as such and the individual images should be stacked so as to provide two observations, noting that an individual image can appear in only one stack. In very rare cases, a single stack may be all that is available: such situations will be handled on a case-by-case basis.
Please note that a new version of Astrometrica will be released which will add the ‘K’ stack code automatically (RD)
* Observations of “new” objects in support of discovery claims should be spaced by at least one and no more than five nights.
It is hoped that self-regulation by observers will be sufficient. If this does not prove to be the case by the end of this month, we will implement additional filters to reject automatically entire batches that contain single observations or new objects with insufficient nightly coverage.
Observers are informed that batches submitted with “corrected”, “correction”, “remeasured” or “remeasurement” in the subject line or ACK line are treated as being corrections to observations published previously and are filed by the automated routines for manual examination by MPC staff. The processing of such batches may be delayed.
It is also worth remarking that resubmission of observations or batches that were rejected by the automated AUTOACK routines do not need to be indicated as resubmissions, as the MPC has no
internal record of the original, rejected batch.
Observations of Dual-Status Objects
A number of objects are designated as both minor planets and comets. Examples include (2060) Chiron = 95P/Chiron and (4015) Wilson-Harrington = 107P/Wilson-Harrington. Astrometry of dual-status objects must be reported under the minor-planet designation, with the magnitudes reported in the asteroidal form. If observations are reported under the comet designation the AUTOACK routines
will change the designation into the minor-planet designation. If there are “nuclear” or “total” magnitudes reported on the observations this causes problems further down the processing pipeline because minor planets cannot be marked with “N” or “T” magnitudes.
Observing at Remote Sites
Observers who use multiple remote observing sites are requested to be extra vigilant in indicating where the observations were made. A number of observations have been received recently when, at the time of observation, the object was below or the sun was above the local horizon at the observing site.
Indication of Observers, Measurers and Telescope Details
In anticipation of the short-term plans for automatic MPEC preparation by the MPC, we remind observers that information given with the OBS, MEA and TEL keywords in the observational header must conform to the formats described here. Observers who do not adhere exactly to these instructions will find that their observations
on automatically-prepared MPECs will not be credited in the way they intended.
‘Naming Pluto’ – a DVD exploring the chain of events surrounding the naming of the planet (as it was then defined) Pluto. Reviewed in the 2009 Issue of the BAA Journal.
Websites which might be of interest
French Astronomical Society (SAF) planetary observations commission – Occultations, Eclipses and Transits
ARPS Website updates
The following pages have been updated;
Observations received, Nov Dec 2009 Observations
And first the good news. The next MACE (Meeting on Asteroids and Comets in Europe) will be held 2010 May 21-23 in Visnjan, Croatia where the very first MACE took place.
Occultation scan be recorded by the CCD drift scan method. How to do this can be found on John Broughton’s website which also references software, ScanTracker and ScanAnalyser, he wrote to do the job.
MPML/David Herald. LimovieAverage is a program that bins the measurements made by Limovie, and normalises the measurements on the basis of a comparison object. Its use is relevant to measuring the light curve of an object. The zip file is available for download at: http://www.asteroidoccultation.com/observations/
The direct download address is: http://www.asteroidoccultation.com/observations/LimovieAverage.zip
MPML/Hristo Pavlov. Following the release of Occult 126.96.36.199 here is the new minor update of OccultWatcher that can now recognize the double star flag from the new Occult predictions and will display events that involve known double stars on a red background. This should be an indication for you that the star coordinates used for the prediction may have a bigger error and for such events bigger path shifts should be anticipated. This doesn’t mean that those predictions are not good, it only means you should treat them as being more likely to have a path shift and take this into consideration when planning a mobile station for example. If you have a version of C2A lower than 2.0.35 installed on your system; uninstall it through the Windows Configuration Panel, download the full 2.0.36 version from the C2A Web site and install it, in Occult Watcher, go into the configuration of the C2A Add-in and change the C2A access path from “C:\Program Files\C2a for Windows” to “C:\Program Files\C2A”. If you have version 2.0.35 installed on your system; download the 2.0.36 C2A update from the C2A Web site and install it (it is much smaller than the full version), in Occult Watcher, go into the configuration of the C2A Add-in and make sure that the C2A access path is “C:\Program Files\C2A”.
If you don’t have C2A yet then go to http://www.astrosurf.com/c2a/english/download.htm
MPML/J Lecacheux. Asteroid (93) Minerva revealed to be a triple asteroid by astronomers using the 10m Keck telescope.
MPML/Andrea Milani. The proper elements, computed with the synthetic method, for more than 4,000 Hungaria asteroids are available on the AstDyS site at
http://hamilton.dm.unipi.it/astdys/index.php?pc=5 The theory behind this computation and many consequences, including the dynamical structure of the Hungaria region, the family classification, etc., are discussed in a preprint available from http://adams.dm.unipi.it/~milani/preprints/ This paper also contains a discussion on “close asteroid couples”, which was actualy started on MPML in January 2008.
MPML/E P Grondine. Argentina can lay claim to the world’s largest crater field, a volcanic area in Patagonia known as the “Devil’s Slope,” according to a study released Tuesday. Covering 400 square kilometers (154 square miles), the Bajada del Diablo field is peppered with at least 100 depressions left by the collisions of meteorites or comets 130,000 to 780,000 years ago, the study found.
MPML/Spacefilght Now. Craters on Vesta and Ceres could tell Jupiter’s age
EUROPEAN PLANETARY SCIENCE CONGRESS NEWS RELEASE
September 14, 2009
Crater patterns on Vesta and Ceres could help pinpoint when Jupiter began to form during the evolution of the early Solar System. A study modeling the cratering history of the largest two objects in the asteroid belt, which are believed to be among the oldest in the Solar System, indicates that the type and distribution of craters would show marked changes at different stages of Jupiter’s development. Results will be presented by Dr. Diego Turrini at the European Planetary Science
Congress in Potsdam, Germany, on Monday 14 September. The study, carried out by scientists at the Italian National Institute for Astrophysics in Rome, explored the hypothesis that one or both objects formed during Jupiter’s formation by modeling their cratering histories during the birth of the giant planet. Their simulation described Jupiter’s formation in three stages: an initial accretion of its core followed by a stage of rapid gas accretion. This is, in turn, followed by a phase where the gas accretion slows down while the giant planet reaches its final mass. During the last two phases Jupiter’s gravitational pull starts to affect more and more distant objects. For each of these phases, the team simulated how Jupiter affected the orbits of asteroids and comets from the inner and outer Solar System, and the likelihood of them being moved onto a collision path with Vesta or Ceres. “We found that the stage of Jupiter’s development made a big difference on the speed of impacts and the origin of potential impactors. When Jupiter’s core approaches its critical mass, it causes a sharp increase in low-velocity impacts from small, rocky bodies orbiting nearby to Vesta and Ceres which lead to intense and uniform crater distribution patterns. These low-speed collisions may have helped Vesta and Ceres gather mass. Once Jupiter’s core has formed and the planet starts to rapidly accrete gas, it deflects more distant objects onto a collision course with Ceres and Vesta and the impacts become more energetic. Although rocky objects from the inner Solar System are the dominant impactors at this stage, the higher energies of collisions with icy bodies from the outer Solar System make the biggest mark,” said Dr. Turrini. The third stage of Jupiter’s formation is complicated by a period known as the Late Heavy Bombardment, which occurred around 3.8 to 4.1 billion years ago. During this time a significant number of objects, rich in organic compounds, from the outer Solar System were injected on planet-crossing orbits with the giant planets and may have reached the Asteroid Belt. In addition, Jupiter is thought to have migrated in its orbit around this time, which would have caused an addition flux of impactors on Vesta and Ceres. The team will have an opportunity to confirm their results when NASA’s Dawn space mission reaches Vesta in 2011 and then flies on for a further rendezvous with Ceres in 2015. Dawn will gather information on the structure and the surface morphology of the two asteroids and send back high-resolution images of crater patterns. “If we can see evidence of an underlying intense, uniform crater pattern, it will support the theory that one or both of these minor planets formed during the final phases of Jupiter accretion, provided that they aren’t obliterated by the later heavy bombardment. Dawn will also measure concentrations of organic material, which may give us further information about the collisional history with organic-rich objects from the outer Solar System,” said Dr. Turrini.
MPML/Ron Balke. In Search of Dark Asteroids (and Other Sneaky Things)
NASA Science News
September 15, 2009
Ninjas knew how to be stealthy: Be dark. Emit very little light. Move in the shadows between bright places. In modern warfare, though, ninjas would be sitting ducks. Their black clothes may be hard to see at night with the naked eye, but their warm bodies would be clearly visible to a soldier wearing infrared goggles.
To hunt for the “ninjas” of the cosmos – dim objects that lurk in the vast dark spaces between planets and stars – scientists are building by far the most sensitive set of wide-angle infrared goggles ever, a space telescope called the Widefield Infrared Survey Explorer (WISE). WISE will scan the entire sky at infrared wavelengths, creating the most comprehensive catalog yet of dark and dim objects in the cosmos: vast dust clouds, brown dwarf stars, asteroids – even large, nearby asteroids that might pose a threat to Earth. Surveys of nearby asteroids based on visible-light telescopes could be skewed toward asteroids with more-reflective surfaces. “If there’s a significant population of asteroids nearby that are very dark, they will have been missed by these previous surveys,” says Edward Wright, principal investigator for WISE and a physicist at the University of California in Los Angeles. The full-sky infrared map produced by WISE will reveal even these darker asteroids, mapping the locations and sizes of roughly 200,000 asteroids and giving scientists a clearer idea of how many large and potentially dangerous asteroids are nearby. WISE will also help answer questions about the formation of stars and the evolution and structure of galaxies, including our own Milky Way. And the discoveries won’t likely stop there. “When you look at the sky with new sensitivity and a new wavelength band, like WISE is going to do, you’re going to find new things that you didn’t know were out there,” Wright says. Stars emit visible light in part because they’re so hot. But cooler objects like asteroids emit light too, just at longer, infrared wavelengths that are invisible to the unaided eye. In fact, any object warmer than absolute zero will emit at least some infrared light. Unfortunately, this fact makes building an infrared telescope rather difficult. Without a coolant, the telescope itself would glow in infrared light just like all other warm objects do. It would be like building a normal, visible-light telescope out of Times Square billboard lights: The telescope would be blinded by its own glow. To solve this problem, WISE will cool its components to about 15°C above absolute zero (or -258°C) using a block of solid hydrogen. Mission scientists chose solid hydrogen over liquid helium, which is often used in research for cooling materials to near absolute zero, because a smaller volume of solid hydrogen can do the job. “The cooling power is much higher for hydrogen than for helium,” Wright explains. When launching a telescope into space, being smaller and lighter saves money. Previous space telescopes such as the Infrared Astronomical Satellite (IRAS) have mapped the sky at infrared wavelengths before, but WISE will be hundreds of times more sensitive. While other missions could only see diffuse sources of infrared light such as large dust clouds, WISE will be able to see asteroids and other point sources. After it launches into orbit as early as this December, WISE will spend 6 months mapping the sky, during which it will download its data to ground stations 4 times each day. Analyzing that data should give scientists some new insights into the cosmos. For example, one theory posits that most of the stars in the Universe were formed in the press of colliding galaxies. When galaxies collide, interstellar clouds of gas and dust smash together, compressing the clouds and starting a self-perpetuating cycle of gravitational collapse. The result is a flurry of starbirth. Newborn stars are usually concealed by the dusty clouds they are born in. Ordinary light cannot escape, but infrared light can. WISE will be able to detect infrared emissions from the most active star-forming regions. This will help scientists know how rapidly stars are formed during galactic collisions, which could indicate how many of the universe’s stars were formed this way. WISE will also target dim “failed stars” called brown dwarfs that outnumber ordinary stars by a wide margin. Mapping brown dwarfs in the Milky Way may reveal much about the structure and evolution of our own galaxy. And this could be just the beginning of the discoveries scientists make once WISE puts the spotlight on stealthy denizens of the dark.
MPML. Richard Kowalski, the discoverer of asteroid 2008 TC3, now has his own piece of it thanks to funds raised by MPML subscribers lead by Herbert Raab.
MPML/Brian D Warner. The free electronic download for The Minor Planet Bulletin 36-4 (2009 October-December) is now available at
http://www.minorplanetobserver.com/mpb/default.htm This has 62 pages, bringing the volume 36 total to 194 pages. The MPB is going almost all-electronic starting with 37-1 (2010 January-March). See the full details on page 194 of the 36-4 issue. Includes papers by ARPS members Peter Birtwhistle and Roger Dymock.
MPML/E P Grondine. Personally signed copies of my book “Man and Impact in the Americas”, my catalogue of recent comet and asteroid impacts in the Americas and the First Peoples’ memories of them, are available to MPML participants for $20, plus $5 shipping US ($25), or plus $15 shipping overseas ($35 total). This is a much lower price than $35 through Amazon. Orders may be sent to E.P. Grondine, P.O. Box 158, Kempton, IL 60946. Be sure to add any special signing requests you may have (for example if the copy is a gift), and especially mention to me if you have Native American ancestry.
Websites which might be of interest
OrbitViewer – added to Links page under ‘Asteroids in general’
ARPS Website updates
January 2010 Observations
Table of contents
The rotation period of asteroid (4080) Galinskij – short paper published in the December 2009 issue of the BAA Journal
Websites which might be of interest
ARPS Website updates
What to observe page – ARPS input to 2010 BAA Handbook added
Meetings page – new meetings added
Asteroid news page – reference to (93) Minerva being a binary added
Links page – websites listed above added
What to observe page – reference to drift-scan timing added
Surprise Collision on Jupiter Captured by Gemini Telescope. Jupiter is sporting a glowing bruise after getting unexpectedly whacked by a small solar system object, according to astronomers using the Gemini North telescope on Mauna Kea in Hawai’i. A spectacular new mid-infrared image is available for download. The new feature on Jupiter was first seen by Australian amateur astronomer Anthony Wesley on July 19th. The object that caused the impact scar could have been a small comet or asteroid. Using the SL9 impacts as a guide, the impacting object was probably just a few hundreds of meters in diameter. Such small bodies are nearly impossible to detect near or beyond Jupiter unless they reveal cometary activity, or, as in this case, make their presence known by impacting a giant planet. The impact site is dark in visible-wavelength images. This mid-infrared composite image was obtained with the Gemini North telescope on Mauna Kea, Hawai’i, on 22 July at ~13:30 UT with the MICHELLE mid-infrared spectrograph/imager. The impact site is the bright yellow spot at the center bottom of Jupiter’s disk. The image was constructed from two images: one at 8.7 micron (blue) and one at 9.7 micron (yellow). The excellent quality of the Gemini images reveals that the morphology of this new impact bears a striking resemblance to that of the larger impact sites seen after the comet Shoemaker-Levy 9 crashed into Jupiter in 1994. The impact was also imaged by the Hubble Space Telescope.
NASA’s Jet Propulsion Laboratory is introducing a new Web site that will provide a centralized resource for information on near-Earth objects – those asteroids and comets that can approach Earth. The “Asteroid Watch” site also contains links for the interested public to sign up for NASA’s new asteroid widget and Twitter account. The new Asteroid Watch site is online at http://www.jpl.nasa.gov/asteroidwatch.
According to a new interim report (also here) from the National Research Council, NASA’s current near-Earth object surveys will not meet the congressionally mandated goal of discovering 90 percent of all objects over 140 meters in diameter by 2020.
New research may have answered a piece to the puzzle – how big were the first planetesimals? The paper, “Asteroids Were Born Big” is available now online from the ScienceDirect website and will be available in a future edition of the journal Icarus. It is also available here.
The Late Heavy Bombardment may have been more cometary than asteroidal. Paper here.
Jupiter targeted again. Antony Wesley’s observations.
The UCAC3 catalog will be released in 2009 August
The Space Missions page includes details on all missions to asteroids.
– WISE, is a NASA-funded Explorer mission, to be launched in 2009 December. Among the objects WISE will study are asteroids, the coolest and dimmest stars, and the most luminous galaxies.
The Asteroid News page contains details of recent discoveries;
– companion to 2002 XH91 discovered
– 1994 CC found to be a triple asteroid
See Meetings page for details on all known meetings)
– The Malta Symposium on Hazardous Near Earth Asteroids will be held at the Russian Cultural and Scientific Center on Malta 2009 October 12-16
– This is a preliminary notice to announce that European Symposium on Occultation Projects (ESOP) XXIX will be held in the City of York, UK, from Friday August 20 to Tuesday August 24, 2010 (inclusive dates). The LOC has secured the York University Conference Centre and accommodation for the above dates.
Observations from members received during July and August 2009 can be accessed here.
Paper ‘A method of determining V magnitudes of asteroids from CCD images’ by Richard Miles and Roger Dymock published in the June 2009 issue of the BAA Journal can be found here. RECOMMENDED READING FOR ALL INTERESTED IN PHOTOMETRY.
Occult Version 188.8.131.52 can be downloaded from http://www.lunar-occultations.com/occult4/occult406%20update.zip Most users of Occult will not need to download this update. However note the ‘Other changes’ below. Anyone predicting Asteroid Occultations ***should*** download the update. The main change in this version concerns the probability estimates for occultations involving slow-moving asteroids. For all occultation predictions, there is an along-track uncertainty that is indicated as an uncertainty in the time of the event. That uncertainty necessarily involves a corresponding uncertainty in the rotational orientation of the Earth. Up until now, that uncertainty in the orientation of the Earth has not been allowed for in the prediction uncertainty – mainly because the effect is usually very small. However when the asteroid motion across the Earth is slow, the effect can be significant. This version adjusts the 1-sigma uncertainty lines, and the predicted uncertainty at a location, for this effect. This correction has immediate relevance for the occultation by Philosophia in Europe on May 2. The 1-sigma uncertainty lines are several 10’s of km further separated from the central path. And the event probability within the path drops in value by about 3% – from about 28% to 25%.
Other changes included are:
– on the main form, access to the 7-Timer weather prediction for your ‘home’ site (limited to cloud and temperature). This provides ready access to a 3-day cloud forecast.
– for lunar occultations, provided some base functionality for reporting double star observations – including the ability to copy and paste a LiMovie light curve directly into an email message from the clipboard..
Details of 2009 Planetary Society Gene Shoemaker Near Earth Object grants to Russell Durkee of Minn., Robert E. Holmes, Jr of Ill., and Gary Hug of Kansas can be found here.
An updated list of Damocloids can be found here.
A procedure developed by Adam Block and Ron Wodaski describing the use of Astrometrica can be accessed here.
A minor update of OccultWatcher and the IOTA Reporting Addin has been released. It can be accessed via Help/Check for updates and following the link to update. All resolved issues are minor except for a bug where version 1.0 of the IOTA Reporting Addin would fill in incorrectly the UCAC2 star number in the excel reports in some cases.
The New Horizons team is fondly remembering Venetia Burney Phair, the “little girl” who named Pluto, who died April 30 at her home in England at age 90. “Venetia’s interest and success in naming Pluto as a schoolgirl caught the attention of the world and earned her a place in the history of planetary astronomy that lives on,” says New Horizons Principal Investigator Alan Stern. In 2006, the New Horizons team named the spacecraft’s student dust counter instrument in her honor, calling it the “Venetia Burney Student Dust Counter.” For the full story, visit: http://pluto.jhuapl.edu/news_center/news/20090508.php.
The Astronomer reports; (6708) BOBBIEVAILE. D. Pray, Carbuncle Observatory, W. Brookfield, MA, U.S.A. et. al., report that photometric observations obtained Apr. 16 to May 3 reveal that minor planet (6708) is a binary system with an orbital period of 24.7 hr according to CBET 1794. The primary shows a period of 8.221 +/- 0.002 hr, assuming a bi-modal light curve, and it has a light curve amplitude of 0.08 mag, suggesting a nearly spheroidal shape. Mutual eclipse/occultation events with a depth of 0.31 mag indicate a lower limit on the secondary-to-primary mean-diameter ratio of 0.57.
The UK Spaceguard Centre in Knighton run by Jay Tate has a new telescope
Minor Planet Bulletin issue 36-3 (2009 July-September) is available as a free PDF download
Asteroid discovery statistics can be accessed here. Amateurs are still doing quite well it would seem.
From the Minor planet Mailing List
May 20, 2009
University of Colorado, Boulder
NASA STUDY SHOWS ASTEROIDS MAY HAVE ACCELERATED LIFE ON EARTH
WASHINGTON — A NASA-funded study indicates that an intense asteroid bombardment nearly 4 billion years ago may not have sterilized the early Earth as completely as previously thought. The asteroids, some the size of Kansas, possibly even provided a boost for early life. The study focused on a particularly cataclysmic occurrence known as the Late Heavy Bombardment, or LHB. This event occurred approximately 3.9 billion years ago and lasted 20 to 200 million years. In a letter published in the May 21 issue of Nature magazine titled “Microbial Habitability of the Hadean Earth during the Late Heavy Bombardment,” Oleg Abramov and Stephen J. Mojzsis, astrobiologists at the University of Colorado’s Department of Geological Sciences, report on the results of a computer modeling project designed to study the heating of Earth by the bombardment. Results from their project show that while the Late Heavy Bombardment might have generated enough heat to sterilize Earth’s surface, microbial life in subsurface and underwater environments almost certainly would have survived. “Exactly when life originated on Earth is a hotly debated topic,” said Michael H. New, the astrobiology discipline scientist and manager of the Exobiology and Evolutionary Biology Program at NASA Headquarters in Washington. “These findings are significant because they indicate that if life had begun before the LHB or some time prior to 4 billion years ago, it could have survived in limited refuges and then expanded to fill our world.” “Our new results point to the possibility life could have emerged about the same time that evidence for our planet’s oceans first appears,” said Mojzsis, principal investigator of the project. A growing scientific consensus is that during our solar system’s formation, planetary bodies were pummeled by debris throughout the Late Heavy Bombardment. A visual record of the event is preserved in the form of the scarred face of our moon. On Earth, all traces of the bombardment appear to have been erased by rock recycling forces like weathering, volcanoes or other conditions that cause the crust to move or change. Surface habitats for microbial life on early Earth would have been destroyed repeatedly by the bombardment. However, at the same time, impacts could have created subsurface habitats for life, such as extensive networks of cracks or even hydrothermal vents. Any existing
microbial life on Earth could have found refuge in these habitats. If life had not yet emerged on Earth by the time of the bombardment, these new subsurface environments could have been the place where
terrestrial life emerged. “Even under the most extreme conditions we imposed on our model, the bombardment could not have sterilized Earth completely,” said Abramov, lead author of the paper. “Our results are in line with the scientific consensus that hyperthermophilic, or ‘heat-loving,’ microbes could have been the earliest life forms on Earth, or survivors from an even more ancient biosphere. The results also support the potential for the persistence of microbial biospheres on other planetary bodies whose surfaces were reworked by the bombardment, including Mars.” NASA’s Astrobiology Program’s Exobiology and Evolutionary Biology Program and the NASA Astrobiology Institute at NASA’s Ames Research Center at Moffett Field, Calif., through its support of NASA’s Postdoctoral Program, provided funding for this research. The Astrobiology Program supports research into the origin, evolution, distribution and future of life on Earth and the potential for life elsewhere.
For more information about NASA’s astrobiology activities, visit: http://astrobiology.nasa.gov
If you are interested in Solar System dynamics then give Solex a try.
AIP4WIN version 2.3.0 is now available.
LISA, the joint NASA/ESA mission to study gravitational waves may be able to measure the mass of nearby asteroids. Passing asteroids may cause the three LISA satellites to wobble in a small but distinctive way. The paper will be published in Classical and Quantum Gravity – http://www.iop.org/EJ/abstract/0264-9381/26/8/085003
ESO 16/09 – Science Release. A new study published in Nature this week reveals that asteroid surfaces age and redden much faster than previously thought — in less than a million years, the blink of an eye for an asteroid. This study has finally confirmed that the solar wind is the most likely cause of very rapid space weathering in asteroids. This fundamental result will help astronomers relate the appearance of an asteroid to its actual history and identify any after effects of a catastrophic impact with another asteroid.
The STEREO spacecraft are entering the Earth’s L4 and L5 points which may hold small asteroids which could be leftovers from the collision between the Earth and a Mars sized body 4.5 billion years ago. More detail.
Peter Jenniskens led an expedition into the Nubian desert to recover hundreds of fragments from asteroid 2008 TC3 that exploded over the skies of Sudan last October. Astronomy Now interview
For the last two years, astronomers have suspected that a nearby white dwarf star called GD 362 was “snacking” on a shredded asteroid. Now, an analysis of chemical “crumbs” in the star’s atmosphere conducted by NASA’s Spitzer Space Telescope has confirmed this suspicion. Read more and more
Websites of interest that have been added to the Links page;
Astrometry ‘how-to’ by Tim Spahr of the Minor Planet Center
Portal to the universe. Although not an asteroid specific site it does include asteroid info and, as they say, much, much, more!!!
A Yahoo group for Project Pluto’s Find_Orb software has been set up at http://groups.yahoo.com/group/find_orb
OccultWatcher 3.2 has been released and can be downloaded from http://www.hristopavlov.net/OccultWatcher/publish.htm
Philippe Deverchère has released a new version of C2A that can now draw prepoint maps for occultation events. You’ll need to download and install C2A ver 2.0.31 to be able to do that. There is also a new version of the C2A Add-in for OccultWatcher. You can download this using the update process in Occult Watcher Go ‘Help’ -> ‘Check for Updates’ and then click on the update link to update the C2A Add-in. Then Go ‘Add-ins’ -> ‘Configure Add-ins’ -> ‘C2A Add-in’ to configure the new settings.
A new version of Occult is available and can be downloaded from IOTA website
Asteroid 7102 has been named after Neil Bone, Director of the BAA’s Meteor Section.
The April-June 2009 issue of The Minor Planet Bulletin can be download from here
The presentation on 2008 TC3 has been updated with information relating to the discovery of fragments
The latest release of the Asteroid Lightcurve Database (LCDB) is now available on the CALL site: http://www.minorplanetobserver.com/astlc/LightcurveParameters.htm This release contains data on 3824 objects in 11014 detail records. This is 403 objects more than the 2008 March release.
A new page, Video processing, describing how to subtract dark frames and make astrometric measurements from video has been added.
2009 BB77 was discovered by ARPS Director Richard Miles on 2009 January 30th while imaging comet 17/P Holmes. Orbit diagram and details here (JPL NEO Program website
(1) Ceres least distance from Earth for 150 years. Jean Meeus has indicated that the dwarf planet (1) Ceres approaches its least distance to the Earth (1.5832 AU) on 2009 February 25 between 2300-0000 UT. Jean tells me that the last time Ceres was nearer to the Earth than 1.5832 AU was on 1857 February 14, when its distance was 1.5815 AU. He has calculated future close approaches and has shown that no approach to the Earth closer than the present one takes place before A.D. 3000! Ceres will therefore be at its marginally greatest angular diameter (about 0.80×0.85 arcsec) at the moment. This does not mean it will be at its brightest since that depends on phase angle. On this occasion, Ceres attains a V magnitude of 6.88. Over the next 25 years, Ceres will actually be brightest on 2012 December 18 reaching V = 6.73. From Richard Miles, Director, Asteroids and Remote Planets Section.
If you want to know how Gauss worked out the orbit of (1) Ceres then read this
Version 184.108.40.206 of Occult is now available at: http://www.lunar-occultations.com/occult4/occult405%20update.zip Just unzip the download file into the Occult 4 directory. A full list of the changes is in the file Updates.txt that will be in the Occult 4 directory.
To estimate the approximate shape of an asteroid from occultation data usually requires positive reports from several observers however Andreas Eberle has developed a method of doing so from a single observation. A report can be accessed here.
Eleanor “Glo” Helin passed away in late January 2009. She was one of the pioneers of the search for Near Earth objects (NEO’s) and established and led the NEAT Project at JPL. The NEAT Program discovered hundreds of NEO’s, many comets, and 64 Potentially Hazardous Asteroids (PHA’s).
From BAA electronic bulletin 00380 – (7102) Neilbone. The following citation has appeared in M.P.C. 65121: (the asteroid was) discovered in 1936 July 12 by C. Jackson at Johannesburg. Neil Bone (b. 1959), a British observer and author of several books, founded the Aurora Section of what is now the Society for Popular Astronomy in 1981 and became director of the British Astronomical Association’s Meteor Section in 1992. He also compiles the “Society News” notes for Astronomy Now. We offer our sincere congratulations to Neil, not only for his accomplishments as described above but also for his many other achievements. Roger Pickard, President
A recent article in the RAS magazine ‘The Tunguska impact event and beyond’ by Bill Napier and David Asher referred to the website of the Holocene Impact Working Group The group includes researchers from different field of geoscience who believed that Holocene comet impacts were more frequent in the recent past than the accepted view. The Members and Publications pages list a number of books and papers.
Magnitude Alert Program (MAP) Alert Page for 2009 is here
A team of French and Italian astronomers have devised a new method for measuring the size and shape of asteroids that are too small or too far away for traditional techniques, increasing the number of asteroids that can be measured by a factor of several hundred. This method takes advantage of the unique capabilities of ESO’s Very Large Telescope Interferometer (VLTI). ESO 04/09 – Science Release
The MESSENGER spacecraft reached its orbital perihelion on 2009 Feb 9 and passed within 0.31 astronomical units (AU) of the Sun. The mission’s imaging team is taking advantage of the probe’s proximity to the Sun to continue their search for vulcanoids – small, rocky asteroids that have been postulated to circle the Sun in stable orbits inside the orbit of Mercury.
A paper ‘Long term impact risk for (101955) 1999 RQ36’ is available here
The Catalina Sky Survey (CSS) has set a new record for NEO discoveries – 565 in 2008 which breaks its 2007 record of 460.
A new book well worth a read. ‘The Hunt for Planet X – New Worlds and the Fate of Pluto’ by Govert Schilling, published by Springer (£14.25). The book is about the discovery of the Edgeworth – Kuiper belt and strongly focuses on the human side of the story, with many personal anecdotes. Probably the first popular-level book that gives an in-depth description of the discovery of Eris (2003 UB313), covers the row over the discovery priority of Haumea (2003 EL61) and the ‘demotion’ of Pluto from planet to dwarf planet. Don’t forget to buy your books at Amazon via the BAA Journal website
Please note that the BAA Observers’ Workshop, Asteroids Comets and Meteors, scheduled to take place in February 2009 has been postponed
Asteroid and Dwarf Planet data for 2009 has been added to the What to Observe page.
Observations by the Spitzer Space Telescope have revealed two asteroid belts around the star Epsilon Eridani
A paper describing the YORP effect in asteroid (1620) Geographis can be found here
2008 TC3 burnt up in the atmosphere over northern Sudan on 2008 October 7. A PowerPoint presentation put together (mainly) from MPML postings can be viewed here (updated 2008 December 17)
A new, intermediate release of the Asteroid Lightcurve Database (LCDB) maintained by Alan Harris, Petr Pravec and Brian D. Warner is available on the CALL site at http://www.minorplanetobserver.com/astlc/LightcurveParameters.htm Please note that it has yet to be completely cross- checked hence the ‘intermediate’ release
The new AstDys information system is now at; http://hamilton.dm.unipi.it/astdys
A dedicated follower of asteroids rather than fashion but possibly that as well !!. Peter Birtwhistle is about to or will have surpassed exactly 10,000 astrometric measures of near-Earth asteroids. He is currently at 9,880 and has also reported a further few thousand astrometric positions of asteroids that happened not to
turn out as NEOs. His very first one was 2002 LG3 on 2002 June 10/11 so it is an impressive statistic and is a monumental achievement requiring dedication, etc. in the face of the English weather! To put it in perspective, Siding Spring in Australia with a professional, Rob McNaught at the helm and others helping out have only managed 12,258 to date! I suspect that Peter has been the most successful and productive at performing NEO follow-up of all amateurs worldwide. Jim McGaha (Sabino Canyon, 854) in Tucson, Arizona started before Peter and is only up to 2,919. (Note by Richard Miles for the Skynotes presentation at the December 2008 meeting of the British Astronomical Association).
Issue 36-1 (2009 January-March) of the Minor Planet Bulletin is available as a free download from
Asteroid families can be identified by their colour – paper here
The UK NEO Information Centre has a new website address
On 2008 October 29 Richard Miles became the new Section Director and Roger Dymock assumed the role of Section Web Site Manager
2008 SV11 – an observing project for the New Year. See ‘What to Observe/Observing projects/Asteroid 2008 SV11’ page for further information
2008 TC3 burnt up in the atmosphere over northern Sudan on 2008 October 7. A PowerPoint presentation put together (mainly) from MPML postings can be viewed here
Close approaches of Potentially Hazardous Asteroids to the inner planets by Andrew Lowe. Andrew’s website has some interesting information on the use of on-line archives to discover asteroids.
Some developments in the reporting of absolute magnitudes can be found here
‘The Great Planet Debate: Science as Process’ conference can be accessed here
Observations recently received from members can be found here
Websites added to Links page;
Desert Moon Observatory
International Occultation Timing Association (IOTA)
Occultation Section of the Royal Astronomical Society of New Zealand
Shed of Science
BAA Observers’ Workshop No. 10, ‘Asteroids, Meteors and Comets’ added to Meetings page. Note date may change.
Study demonstrates how binary asteroids and asteroid moons might have formed
Dwarf planet 2005 FY9 named Makemake after the Polynesian creator of humanity and the god of fertility – IAU press release IAU0806
‘Bolides and Meteorite Falls’ International conference on the occasion of the 50th anniversary of the Pribram meteorite fall to be held at the Hotel Michael, Prague, Czech Republic, 2009 May 10-15
Rosetta spacecraft – asteroid (2867) Steins fly by
1st IAA Planetary Defense Conference, Protecting Earth from Asteroids, to be held in Granada, Spain 2009 April 27-30
MIT solves puzzle of meteorite-asteroid link
Astronomers find an unusual new denizen of the Solar System – 2006 SQ372
Minor Planet Bulletin 35-4 (Oct-Dec 2008) is now available as a free download (Zipped PDF)
International Team of Astronomers Finds Missing Link (not early man but an asteroid, 2008 KV42, possibly originating from the Oort Cloud !!!)
Possible existence of an outer planet beyond the Edgeworth-Kuiper Belt and much more by Patryk Sofia Lykawka
Two articles previously published in the Journal of the British Astronomical Association have been added to this website;
– ‘Asteroids: past, present and future’. 2007 Presidential Address by Richard Miles
– ‘The H and G magnitude system for asteroids’ based on 2007 February 24 BAA Observers’ Workshop at the Open University in Milton Keynes by Roger Dymock
Two books have been added to the ‘Books’ section
‘Setting up a Small Observatory’ by David Arditti
‘Clyde Tombaugh, Discoverer of Planet Pluto’ by David H. Levy
Two robotic telescope sites have been added to the ‘Links’ page
– Bradford Robotic Telescope
Observations recently received from members can be found here
Canada to launch NEOSSAT in 2010 to hunt for Near Earth Objects – more info here
Asteroid 6137 named after John Fletcher – more info here
Orbit@home is a distributed computing project to NEA search strategies and to monitor the NEA impact hazard
List of asteroid masses is available here
Pluto and Eris are Plutoids as well as dwarf planets – read IAU Press release IAU0804 for the full story
The Asteroid Dynamics website has a new interface under test here
The latest Minor Planet Bulletin, 35-3: 2008 July-September, is available as a PDF here
Is your PC clock accurate ? – read more here
Zhongguos and Griquas – all you need to know
Largest impact crater in the solar System ? – NASA report here
Andrew Elliot looking after the ARPS stand at the 2008 Exhibition Meeting
To return to the What is Happening page. Select here
To return to the Section home page. Select here