Notes upon the 2013–14 apparition of Mars
Mars will be at opposition on 2014 April 8 (with a seasonal date defined by Ls = 114º, corresponding to early summer in the martian northern hemisphere) with a diameter of 15.1 arcseconds, bringing the planet a little nearer than in 2012. Closest approach occurs on April 14 and the declination will be around –5º. The planet’s diameter will be 6” or greater between 2013 mid-December and 2014 October, so observations (if not yet begun) ought to start as soon as possible.
For seasonally comparable oppositions from the past, the 1950 and 1952 approaches (at Ls = 97º and 136º respectively) will serve us well in showing the planet close to the N. summer solstice and in N. midsummer, respectively. From 1950 we offer some previously unpublished sketches from the notebook of Edward Collinson, then living at Felixstowe, who went on to become Mars Section Director from 1956 to 1979. Collinson (Fig. 1) experienced some spells of superb seeing in the spring of 1950 and, although the opposition was aphelic, he later told the writer that he did his best Mars work during that year (Fig. 2) The BAA’s most prolific contributor at the next opposition of 1952 was Tsuneo Saheki (Fig. 3), who lived at the time in Osaka, Japan. We have many of his original pencil sketches, and some are reproduced for the first time here (Fig. 4) to show some of the changeable features to look for in 2014. Saheki had a tendency to show small details in the form of streaks, whereas Collinson was more conservative, and Figs. 3 and 4 can be compared directly. Both observers placed the markings accurately.
The martian albedo features vary considerably over time due to shifting dust deposits on the surface. In the 1950s the planet looked rather different from what it does today. The IAU albedo map by G. de Mottoni also dates from that epoch, being based upon photographs obtained between 1941 and 1952. There was the very prominent Nepenthes curving out of the E. (or p.) side of Syrtis Major, running as far north as Thoth (or Nodus Alcyonius, the latter in a slightly different position some 10 degrees E. of where it is today). Cerberus–Trivium Charontis was much more prominent than it is now: it has been faint since the mid-1980s. In the old drawings there is also marked a very large development just E. of Utopia, which was known as Nodus Laocoöntis. Though not illustrated here, the features around Nilokeras were also subtly different from today, and Solis Lacus was much smaller. Future dust storms could modify these markings at any time: the Director has been waiting for the reappearance of Nepenthes for forty years – so far without success!
Although we can never predict exactly how the surface markings will appear, we can certainly anticipate white cloud and polar cap behaviour rather accurately, and as illustrations we refer readers to the images taken at the opposition of 1999, 15 years earlier. At opposition the planet will be experiencing early summer in the N. hemisphere (summer solstice being reached at Ls = 90º), and the decay of the N. polar cap will be well advanced. Look also for any rifts in the residual cap and outlying, recently detached parts. There will be extensive white cloud activity, and it is an optimum time for imaging the equatorial cloud belt in blue light: telescopically, this begins to be prominent around Ls = 45º. Also expect to see the several evening orographic clouds over the martian volcanoes. Another interesting feature, described and illustrated in the second Interim report on the 2011–12 apparition is the onset of cyclonic clouds over Baltia (NW of Mare Acidalium) at the edge of the NPC. The seasonal onset of the N. polar hood will be observable in 2014: it does not occur simultaneously at all longitudes, and it may dissipate and reform before becoming permanent. The time to watch is around Ls = 160º (2014 mid-July).
Small scale dust activity may be seen at almost any time, but large scale activity is not likely to be witnessed before the S. spring equinox at Ls = 180º (2014 mid-August). Any such event should be reported at once.
Map resources, references to books, and past reports, as well as the current Section Programme, are all posted on this website.
Mars in 2013–14: First Interim Report
Observations of Mars were commenced by some observers as early as the summer of 2013, and I thank P. Abel, M. Adachi, L. Aerts, T. Akutsu, K. N. L. Bailey, S. Ghomizadeh, D. Gray. R. Haddon, T. Ikemura, M. Kardasis, E. Morales, D. C. Parker, D. A. Peach, J. Sussenbach, G. Walker, and K. Yunoki for their early-morning contributions up to the time of writing (2013 late November).
Rather than giving a detailed report here, I have picked out four observations and describe their significance in the captions to Fig. 5. A recent change in the Nodus Alcyonius area is very significant, given that the feature had changed little in over 30 years.
Please send me your work regularly and help to make this another memorable opposition!
1 BAA Handbook for 2014.
2 According to M. Minami (in the Oriental Astronomical Association’s Communications in Mars Observations, No. 175
(1996)) Saheki was born (as Tsuneo Watanabé) on 1916 October 3. His main telescope was a 22-cm Newtonian.
He took the name Saheki upon his marriage in 1942, and from 1946 onwards he directed the OAA Mars Section
with much energy until his retirement in 1990. He often wrote reports in the OAA’s Journal, The Heavens, of which
the was once editor. One of his particular interests was the development of the feature Nodus Laocoöntis from
1946 onwards (see the Letter to the Editor entitled ‘Nodus Laocoöntis and A. W. Wilkinson’s map of 1948’ by
Takeshi Sato, together with the Director’s comments in J. Brit. Astron. Assoc., 96 (1985), 8–9), as well as the study
of short-term brightenings of ‘flashes’ on the planet’s surface. (See the BAA 2001 final report for reproductions of
Saheki’s 1954 observations: R.J.McKim, J. Brit. Astron. Assoc., 119 (2009), 123–43 and 205–11.) He was President
of the OAA 1990–93, and died, aged 79, on 1996 February 22. His BAA contributions were limited to the 1950s; it
is a pity that our Mars Section at that time (directed by P. M. Ryves, 1942–56) was much less active, and never
published his work at the time.
3 R. J. McKim, J. Brit. Astron. Assoc., 117 (2007) 314–30; see mars1999.pdf.
4 R. J. McKim, ibid., 123 (2013), 6-7.
Fig. 1. Edward Collinson at the
Fig. 2. Mars in 1950, drawn by E. H. Collinson (25-cm Newtonian, x350). (Mars Section archives.) A: Apr 6d 2145UT, ω = 229º. Cerberus–Trivium Charontis is much more prominent than today, and a small orographic cloud over Elysium follows it. The great curve of Nepenthes was seen to be highly broadened and (together with Casius) spotty, under excellent seeing conditions. B: Mar 24d 2215UT, ω = 350º. Ismenius Lacus is rather prominent, much more so than in recent decades. Otherwise this face of Mars is very much as it is today. The Syrtis Major was faint and pale bluish-grey, affected by evening cloud. Much fine detail was detected in superb seeing.
Fig. 4. Mars in 1952, by T. Saheki (20-cm Newtonian). (Mars Section archives.) A: May 12d 1100UT, ω = 244º, x285. The temporary dark area known as Nodus Laocoöntis, east of Nodus Alcyonius, is dark and complex, having reached its peak area in the early 1950s. The Syrtis Major is covered by morning cloud except at its northern tip. B: May 7d 1500UT, ω = 348º, x330, x400. The ‘canals’ are rather strongly depicted here, and the NPC is considerably smaller than in March. An evening cloud projects slightly beyond the limb, and partly covers the Syrtis Major.
Fig. 3. Tsuneo Saheki observing Mars in 1956.
Fig. 5. Images and drawings of Mars in 2013. A: Sep 26d 1049UT, ω = 267º, ASI 120MM RGB image with 40-cm SCT, D. C. Parker. Despite the 4.3 arcsecond diameter, this image shows a new dark streak running NE from a rather faded Nodus Alcyonius, the small patch just below the disk centre (and NE of the tip of Syrtis Major). Fragments of Nepenthes may be visible. This change must be the result of recent dust activity, and similar detail was also shown there by Peach on Sep 20. Images from Oct–Nov (several observers) subsequently showed Nodus Alcyonius and the S. part of Casius considerably faded. Nodus Alcyonius had appeared strongly at each apparition since 1982, but in 1980 and for a few oppositions immediately beforehand it was faint: it acts as a useful ‘litmus test’ for dust deposition in the area. As of 2013 Nov the area more reminds the writer of the 1978 opposition. B: Sep 30d 0535UT, ω = 152º, drawing with 41-cm Dall–Kirkham Cassegrain, x365, x535, D.Gray. Elysium is light on the morning limb and a bright patch marks the place of Olympus Mons just p. the CM. C: Oct 6d 0527UT, ω = 091º, RGB image with 36 cm SCT, D.A.Peach. There are traces of the seasonal annular rift within the N. polar cap. Solis Lacus is conspicuous to the south, and equatorial evening cloud covers Chryse–Xanthe. It is still too early for the development of a conspicuous equatorial cloud belt.
Richard McKim, Director