Author: BBC World Service

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)

Vermillion red, vibrant orange, golden yellows, even violet – we're enchanted by the colours that make up a stunning sunset or sunrise. CrowdScience listener Paulina, a lighting designer from Chile, often uses the sunsets she sees from her balcony as inspiration for her designs. And during the day and night, the sky can be all sorts of shades of blue. But Paulina wonders why, in the colour palette of the sky, she never sees any green.

CrowdScience gazes skywards to investigate. Presenter Caroline Steel travels to the Arctic Circle to meet atmospheric physicist Katie Herlingshaw. Katie explains why we usually see the sky as blue, and what makes it transform into fiery reds and oranges at sunrise and sunset. We also peer into the science of perception, as neuroscientist Bevil Conway tells us what’s going on in our eyes (and brains) to make the colours we see in the sky.

But there are some rare occasions when the sky can appear to be green, such as in a rainbow or a green flash at sunset. And then there is the spellbinding green glow of the aurora - the Northern and Southern Lights. We visit the northernmost aurora observatory in the world to try to understand this phenomenon. Are green skies more common than we think?

Presenter: Caroline Steel Producer: Hannah Fisher Editor: Cathy Edwards Production Co-ordinator: Ishmael Soriano Studio Manager: Sarah Hockley

(Photo: View of sunset in Santiago, Chile. Photo montage courtesy of Paulina Villalobos)

Monty the giant schnauzer won best in show at the Westminster Kennel Club Dog Show. And rather than thinking of all things canine, this week the Unexpected Elements team turn their attention to all things giant.

First, we find out how a giant virus could help keep our planet cool.

Next up, we discover the origins of enormous Greek characters, such as the Titans and the Cyclops. We then find out how giant clams put solar panels to shame.

Plus, we’re joined by Professor Shinobu Ishigaki, director of the Museum of Dinosaur Research at the Okayama University of Science. He tells us about the ginormous footprints he found in the Gobi Desert, and what they could teach us about herbivorous dinosaurs.

That, plus many more Unexpected Elements.

Presenters: Caroline Steel, with Chhavi Sachdev and Camilla Mota. Producers: William Hornbrook, with Alice Lipscombe-Southwell, Debbie Kilbride, Imaan Moin and Noa Dowling.

The Lancet this week features a paper calling for a financially sustainable network of influenza labs and experts across Europe. Marion Koopmans was one of the 32 expert signatures, and she describes how Europe needs to learn some lessons from the model developed previously in the US. The ongoing worries around avian H5N1 would be a great example of why funding for that sort of frontline strategic science needs not to be reliant on ad-hoc, potentially political, funding grants.

This weekend, a conference is taking place in Asilomar, CA, to mark 50 years since the 1975 conference there at which scientists developed some rules and guidelines around the future practice of genetic science. The historic Asilomar conference is celebrated by many as the moment scientists first demonstrated that they could spot risks, and self-regulate their activities, around novel and disruptive technologies. Author and scientist Matthew Cobb of the University of Manchester, and Shobita Parthasarathy of the University of Michigan discuss how perhaps other perspectives on the Asilomar legacy should be considered.

Presenter: Roland Pease Producer: Alex Mansfield Production Coordinator: Jana Bennett-Holesworth

(Image: Herbert Boyer (UCSF) and Paul Berg (Stanford) at a conference at Asilomar, February 26, 1975. Credit: Peter Breining/San Francisco Chronicle via Getty Images)