Just two weeks ago the world learned of an asteroid that had an almost 3% chance of striking earth in less than a decade. Astronomers kept looking, and a team including Olivier Hainaut at ESO’s Very Large Telescope at Palanar, in Chile, have managed to narrow down the uncertainty such that we now know it will definitely not hit the earth. The secret of making such observations after most telescopes could no longer see it was down to the exceptionally dark skies there.

But these may be under threat. A plan has been made to build a large power plant, including sustainable hydrogen production around 11km away from the otherwise isolated site, and astronomers around the world are rallying to call for the plant to be built further away so that its construction will not spoil the otherwise unique observation conditions.

One of the signatories of a petition to that effect is Julia Siedel, also of ESO, who just last week published the first 3D atmospheric analysis of an exoplanet’s climate. As she explains, future similar observations using the forthcoming, co-sited Extremely Large Telescope could be thwarted before the telescope is even finished.

Back on earth, the Atlantic Meridional Overturning Current (AMOC) continues to bring warmer air and nutrients north towards the Arctic, and colder, denser water south in the global ocean overturn. But are reports of its collapse under climate change justified? A new paper this week suggests that for the next century at least it is stable though it might slow down. Jonathan Baker of the UK Met office explains how the winds in the south mean the cycle will keep turning, though it may slow down.

Talking of the Arctic, Yoel Fink of MIT has dressed a couple of royal marines in wearable computer fibres for their current icy patrol in the north of Canada. Far from going commando, their underwear is measuring temperature and calorific burn to help them avoid frostbite and the dangers of the extreme environment. Yoel’s paper this week describes the new device and the principle that in the future much of all of our healthcare will be provided by these sorts of wearable, stretchy, computing textiles monitoring our activities.

Presenter: Roland Pease Producer: Alex Mansfield Production co-ordinator: Jana Bennett-Holesworth and Josie Hardy

(Photo: Celestial conjunction at Paranal. Credit: Y.Beletsky/ESO)

The Dark Side and the Light (Ephesians 5)