Archives

Results for the planet’s dayside were described in Part I. Here we discuss the nocturnal hemisphere, with details of infrared thermal emission (IRTE) imaging and the Ashen Light (AL). Images of the IRTE revealed up to nine topographic features upon the surface of the planet and enabled the slow rotation rate of the surface to be measured for the first time from amateur images. D. Gasparri recorded subtle, IR-absorbing low-altitude clouds of large scale, which were more prominent in 2009 than in 2017. The 2017 inferior conjunction saw remarkable high resolution reached by P. Miles & A. Wesley: the small bright spots they resolved upon the planet’s surface might provide evidence for active volcanism. The AL was recorded in a small number of visual observations, with only a few sightings confirmed by a second observer. The few positive AL sightings seem to be linked to solar Coronal Mass Ejection events. We review possible mechanisms to account for the AL.

This report describes and analyses observations of the brighter or more interesting comets discovered or at perihelion during 2014, concentrating on those visually observed or discovered by amateur observers. Magnitude parameters are given for all comets with observations. Any evolution in the magnitude parameters of those periodic comets with multiple returns is discussed. Additional information on the comets discussed here, and on other comets seen or at perihelion during the year, may be found on the Comet Section’s visual observations Web pages.

A summary by the Assistant Director of the Aurora & NLC Section of noctilucent cloud (NLC) activity during the 2017 season.

This paper examines claims that the explorer Henry Hudson saw sunspots with the naked eye during sea voyages in both 1590 & 1609. It is argued that there is no evidence to link Hudson with the 1590 observations, and that the presumed sunspot of 1609 – accepted by some leading experts in the history of solar activity – is based on a false premise.

Fourteen successive morning and evening elongations of Venus from 2007–’17 are reviewed. The work of 153 observers covered the time period of ESA’s Venus Express and Japan’s Akatsuki missions, and wavelengths from 335–1750nm. Part II will discuss phenomena of the nocturnal hemisphere: the infrared thermal emission from the planet’s surface, and the Ashen Light.

In this study we examine a lunar dome, identified using CCD terrestrial imagery, LROC WAC images, Clementine multispectral data and the LROC WAC-based GLD100 DTM. The dome lies near Cavalerius A and Hevelius A, in a complex region known as Hevelius Formation, showing evidence of ancient (pre-Orientale) mare volcanism and cryptomare deposits.

Alice Grace Cook (1877–1958, and usually known by her middle name) was one of the first female Fellows of the Royal Astronomical Society. She was also briefly the Director of the British Astronomical Association Meteor Section. However, she is a little-known figure. This paper presents an overview of her life and contributions to astronomy.

This article presents a synopsis of the activity in Jupiter’s North Equatorial Belt (NEB) from 1986–2010, and of the speeds of dark formations on its south edge and bright streaks (‘rifts’) in its interior. In particular I discuss NEB expansion events (NEEs), which took place every 3–5 years during this time, and how the various features of the NEB are involved in them.