Astronomers of the Future Club - May 2019 Meeting Report by Duncan Lunan
by Duncan Lunan - 13:46 on 16 June 2019
Astronomers of the Future Club - May 2019 Meeting Report
by Duncan Lunan
Photo Credit: Linda Lunan
At the meeting of the Astronomers of the Future Club in Troon on Thursday May 30th, the speaker was John Pressly of the Coats Observatory, Paisley, on “Pluto and New Horizons”. He began with a brief account of the refurbishment now under way at the Observatory, part of a £42 million redevelopment of the area. The Observatory will reopen to the public in 2022.
Pluto was discovered by Clyde Tombaugh, after a search taking more than nine years, begun by Percival Lowell, better known for his study of the supposed ‘canals’ on Mars. The name ‘Pluto’ was suggested by English schoolgirl Venetia Burney and passed unanimously by the Lowell Observatory staff, not least because it incorporated their founder’s initials. Such decisions now rest with the International Astronomical Union, and 85 years later they decided to demote Pluto to the status of ‘dwarf planet’, because it’s now known to be one of more than 1500 related bodies in the ‘Kuiper Belt’ of the outer Solar System.
The New Horizons mission to Pluto passed Jupiter in 2007, Pluto in 2015, and the Kuiper Belt asteroid Ultima Thule, the most distant object visited so far, in January 2019. The biggest surprise from Pluto was that its surface is relatively young and active, with none of its features more than 100 million years old. Its crust is mainly nitrogen ice, with deposits of frozen methane and mountains of water ice, which behaves like rock at that distance from the Sun. Nevertheless there is internal heating due to radioactivity, and there may well be a liquid water ocean inside Pluto.
Ultima Thule was thought to be a double asteroid, but has turned out to be a pancake-shaped disc, fused at right-angles to a spheroid, probably since the early history of the Solar System. Yet the surface, which is mostly covered by reddish organic compounds termed ‘tholins’, has bright areas which suggest more recent activity. With the low output of the onboard transmitter, it will take 20 months to download all the data and more surprises are expected. Meanwhile it’s thought that the New Horizons power supply can be made to last till 2030, ten years longer than planned, and as there’s still fuel in reserve a third encounter is possible, if a suitable target can be found.
The next meeting of the Astronomers of the Future Club will be on Thursday June 27th, from 19:15 to 21:00 hrs at the RSAS Barassie Works Club, 4 Shore Road, Troon, KA10 6AG. The speaker will be Chris O’Kane of the Astronomical Society of Glasgow, with “Memories of Apollo”, anticipating the 50th anniversary of the Moon landing next month. For more details, contact Alan Martin on 07947 331632, or see the AOTF Club web page (http://www.actascio.org/aotfclub.asp).
Duncan Lunan’s recent books are available from the publishers, through bookshops or on Amazon. Details are on Duncan’s website, www.duncanlunan.com.