Mercury could be home to alien life – hidden below its barren and battered surface.
That is the astonishing finding from a new study which has discovered possible salt glaciers on the tiny planet – similar to the extreme conditions that support life on Earth.
The findings could revolutionise the search for extraterrestrial life.
The glaciers are thought to lie in some of Mercury’s brilliantly-named ‘chaotic terrain’, officially known as Borealis Chaos, a landscape covered in craters and ridges around the north pole.
For many years astronomers thought the weird terrain may have been formed as a result of massive earthquakes racing through Mercury’s core after a huge collision with a comet or asteroid on the other side of the planet, but the exact cause is still unknown.
But more exciting than how it appeared is what it might be hiding.
‘Specific salt compounds on Earth create habitable niches even in some of the harshest environments where they occur, such as the arid Atacama Desert in Chile,’ said lead author Dr Alexis Rodriguez, from the Planetary Science Institute.
‘This line of thinking leads us to ponder the possibility of subsurface areas on Mercury that might be more hospitable than its harsh surface.
‘These areas could potentially act as depth-dependent “Goldilocks zones”, [comparable] to the region around a star where the existence of liquid water on a planet might enable life as we know it.
‘In this case, the focus is on the right depth below the planet’s surface rather than the right distance from a star.’
The lowdown: Mercury
- Mercury is pretty dinky – it’s only slightly bigger than our Moon and about a third the width of Earth
- It’s quick though, taking only 88 Earth days to whizz around the Sun
- However, one full Mercury day lasts 176 Earth days – more than two Mercury years!
- On average, it’s about 36 millions miles away from the Sun – the Earth is about 93 million miles away
- Mercury doesn’t have any rings or Moons
In short, the findings mean life could feasibly exist on Mercury.
‘This groundbreaking discovery of Mercurian glaciers extends our comprehension of the environmental parameters that could sustain life, adding a vital dimension to our exploration of astrobiology also relevant to the potential habitability of Mercury-like exoplanets,’ he said.
Dr Rodriquez and the team analysed data from Nasa’s now retired Messenger probe to find evidence of the salt glaciers – which aren’t like the glaciers we see on Earth.
Instead, they are large flows of salt trapped beneath the surface within the planet’s ‘volatile-rich layers’ (VRLs), bands of chemicals that evaporate when exposed to air. This is particularly intense on Mercury because it is so much hotter than Earth, being far closer to the Sun.
On Mercury, the Sun appears three times as large and is seven times as bright as it does here.
This meant finding the glaciers was something of a surprise, but the team is confident the remnants exposed by asteroid impacts were caused by salt flowing underneath.
If correct, the consequences would be enormous.
The search for extraterrestrial life has long focused on finding the conditions suitable for simple microbial organisms, water being the key ingredient.
However, even on Earth some highly-specialised bacteria are able to live in very dry conditions, including salt-loving bacteria.
These organisms are known as ‘extremophiles’ for their ability to thrive in harsh, extreme conditions.
Others include bacteria capable of living in very hot water around vents on the ocean floor – similar to those that might be found deep beneath the surface of icy moons.
Earlier this year, a mission to search for life on three of Jupiter’s icy moons blasted off. It will reach the gas giant in seven years.
MORE : Bizarre giant ‘candy floss’ planet is covered in clouds of sand
MORE : Mystery of ‘the Brick’ in middle of the Milky Way finally revealed
MORE : UK’s top UFO expert gives his verdict on the ‘ten aliens’ found by US government
Get your need-to-know
latest news, feel-good stories, analysis and more
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
