Svitloo

He has the ability to align two pictures of a subject taken from slightly different angles to give a sense of perspective - making a 3D view of a scene. He and collaborator Claudia Manzoni did this for the shortlist of possible sample sites on Bennu. They established the safest places to approach.

"I always say you need art as well as science," Sir Brian told BBC News. "You need to feel the terrain to know if the spaceship is likely to fall over or if it will hit this 'rock of doom' that was right on the edge of the eventual chosen site, called Nightingale. If that had happened it would have been disastrous."

Scientists say limiting temperature rise to 1.5C is crucial to avoid the most dangerous impacts of climate change - although these increase with every extra increment of warming.

The 1.5C warming limit was partly designed to avoid crossing so-called "tipping points".

These are thresholds beyond which changes could accelerate and become irreversible in different parts of the Earth's climate system, such as the collapse of the Greenland Ice Sheet.

But it's not clear precisely where these thresholds sit. Some may have already been crossed; some may be further away than first thought.

The mysterious phenomenon of dark energy might provide a solution. In the 1990s, astronomers found that the expansion of the Universe was speeding up, rather than slowing down as might have been expected.

"Something out there is having an 'anti-gravity' effect - it's pushing rather than pulling. We don't know what that is, but it makes up most of the Universe. We call it dark energy," says Prof Tamara Davis, a cosmologist at the University of Queensland in Australia.

On the micro-scale, there are tiny columns or pillars within the rock that trace the connections between the individual "mats" of microbes that build the stromatolites.

"These are strongly, strongly representative of a kind of microbial growth texture, which we call palisade structures," Dr Hickman-Lewis explained.

Two big engine firings from Orion's European Space Agency-provided propulsion unit - the first occurring last Thursday, and the second in the past few hours - have since turned the ship for home.

Nasa is describing the return as its "priority one" for the mission. Engineers want to see proof that the vehicle can survive the heat of re-entry into Earth's atmosphere.

The Ariane doesn't have the energy to send Juice directly to Jupiter, certainly not within a useful timeframe.

Instead, it will dispatch the spacecraft on a path around the inner Solar System. A series of fly-bys of Venus and Earth will then gravitationally sling the mission out to its intended destination.

Arrival in the Jovian system is expected in July 2031.