H
Adios, Arecibo
appy new year everyone. Hopefully 2021 will be much better than 2020, which ended with
disaster at the world-famous Arecibo radio telescope. At the beginning of December the cables
holding Arecibo’s 816 metric tonne instrument platform gave way, sending the platform crashing
into the telescope’s dish far below. It’s scary how quickly the telescope collapsed, from the rst
auxiliary cable breaking in August, to a main cable in November, and then the entire structure
unravelling less than a month after that. Camera footage provided by the National Science
Foundation shows the dramatic moment of collapse, which you can view at
nsf.gov/news/special_reports/arecibo/index.jsp.
In losing Arecibo, we haven’t just lost a telescope, we’ve lost an icon. Famed for the message that it
beamed to the M13 globular star cluster in 1974 (as targets go, it wasn’t the best place to hope to
nd life), Arecibo did so much more than that. It discovered pulsars, made important advances in
fast-radio-burst research, and its planetary radar was a vital rst line of defence against potentially
hazardous asteroids, by tracking their movements and helping scientists characterise them.
Although Arecibo was a xed-dish telescope – meaning that it could not move to point at a target,
but had to wait for that target to wheel overhead as the Earth rotated – its 305-metre dish was
enormous, the largest in the world until the construction of China’s FAST telescope in 2016, which
gave Arecibo a level of resolution unmatched by other radio telescopes.
It’s not yet clear whether a replacement for Arecibo is on the cards, and even if it is, it would take
many years to come to fruition. It may well be that any replacement will not be one single large
telescope, but an array of smaller telescopes working in unison, as at the Allen Telescope Array in
California, or the forthcoming Square Kilometre Array in South Africa and Australia. Where that
would leave a replacement for Arecibo’s powerful radar transmitter is, however, uncertain.
What is certain are the winners of the competition in our October issue, in conjunction with
publishers Collins, to win books and tickets to see the Astrophotographer of the Year exhibition at
the National Museums Greenwich in London. We asked the question, who was the overall winner
of this year’s astrophotography competition. e answer was Nicolas Lefaudeux for his image of the
Andromeda Galaxy. First prize of tickets and books went to Jayme Meadows of Suffolk. e runners
up, who each receive a bundle of books, were Peter Johnson of Cambridgeshire and Colin Spraggs
from Cornwall. Congratulations to you all.
e next, February, issue goes on sale on 21 January.
ViewAdios, Arecibo
January 2021
Astronomy Now