New-found planet may have life on it: Here's what we know so far

COULD there really be life on other planets, and would it resemble any known species on Earth...even the human race? Popular culture has been full of inventions of extraterrestrial creatures, from little green men with multiple eyes to white, pointy-faced Munch-style Scream faces, but almost 60 years on from the moon landings, we're still none the wiser.

Space scientists have been focusing mainly on Mars in recent years, but their Holy Grail could be closer to home: Barnard B, a 'Super-Earth' discovered just this week, is a mere six light years from our own planet and may well hold the key to the question we've been asking ourselves for decades: what does life elsewhere in the universe actually look like?

Among the 60-plus researchers from 10 countries, astronomer Ignasi Ribas from Spain's High Council of Scientific Investigation (CSIC)'s Institute of Space Sciences and member of the Catalunya Space Studies Institute is the main author of the reports being avidly digested worldwide about this unexpected discovery.

In an interview on Friday with the Spanish media, Ribas tells us, in a nutshell, what's been found out to date about this brave new world.

 

What's it like?

According to Ribas, Barnard B – named after the star it orbits, called Barnard – is at least 3.2 times the size of Earth, and its year lasts 233 Earth days. Its distance from Barnard, its sun, is 40% of that of our own, but the 'new' planet only gets 2% of the amount of light Earth receives; its sun is very weak, and the planet's temperature – at least at this time of year and in the parts seen so far – is an unthinkable -170ºC; unsurprisingly, it is covered in ice.

As yet, researchers are unsure what lies beneath the ice – whether it is rocky, or less dense, like a smaller version of Neptune.

What they do know is that the sun Barnard is nearly twice as old as our sun, between seven and 10 billion years, and relatively inactive.

Barnard B sits in the so-called 'ice line' – an area within the orbit of a star where volatile compounds such as water condense and become solid – meaning it is 'very improbable' the planet has water on its surface, Ribas reveals.

But it may have water in the subsoil, which could be conducive to life, despite the exceptionally hostile conditions.

“At times, life does find ways of adapting to be able to survive,” Ribas argues.

 

What type of life might survive in such extreme conditions?

Barnard B is 'far from what we would call an inhabitable zone', in Ribas' exact words – this being defined as a planet at the right distance from its sun to have unfrozen water on its surface.

“If it does have life – and we haven't ruled this out – it would be similar to what we expect would be found on Jupiter's and Saturn's frozen moons, such as Europa or Encelado,” Ribas explains.

 

Which of the Solar System's planets does Barnard B most resemble?

“It's precisely the type of planet which doesn't exist in our Solar System,” Ribas says.

“Barnard B is what we call a 'Super-Earth' – a space object larger than Earth but with 10 times less mass.”

Ribas discovered another planet in 2016, which he named Próxima B ('Near B'), and says Barnard B is similar insofar as both of them orbit much smaller stars and which give out far less heat than our own sun. This earlier planet, named after its sun, Próxima, is also very close to the Solar System, at just 4.2 light years away.

Próxima's temperature is 3,000ºC and Barnard's is 3,300ºC, although Próxima B's climate is milder – it is within what Ribas calls the 'inhabitable zone', meaning it could, potentially, have water on its surface.

 

What was involved in the Barnard B investigation?

Described as 'a major challenge' for space researchers and one of the biggest international space observation projects in history, the discovery involved collating more than 20 years' worth of data captured via over 770 methods using seven different instruments in observatories all over the world, and spending two years analysing them. And it could be no further information exists about either Barnard B or Próxima B, but the 60-strong team – which includes scientists from the Astrophysics Institutes of Andalucía and the Canary Islands, Madrid's Complutense University and Barcelona's Astrobiology Centre (CAB) - intends to keep studying both and looking out for possible signs of other planets in their vicinity.

 

How did the team find it?

The 'Doppler Technique' – one of numerous methods designed by astronomers to seek out planets impossible to spot by direct observation – was employed in the case of Próxima B and Barnard B. The presence of a planet creates effects on the star it orbits, meaning planets can be traced by observing stars.

“When a light source comes close to its observer, its spectrum moves slightly towards blue and its waves are shorter; when the light source moves further away, the spectrum shifts towards the red and its waves become longer,” Ribas explains.

“Gravity on the planet makes the star it orbits move, too.

“So, when we see a star apparently moving to and fro, we can probably infer that there's a planet orbiting it.”

Ribas' co-author Cristina Rodríguez-López says the discovery is a 'significant step forward' in the search for planets beyond the Solar System that may house suitable conditions for life to survive on their surface.

Spanish scientists were joined in this massive mission by space researchers from the UK, USA, France, Germany, Switzerland, Chile, Israel, China and Poland.