Mercury is well known for its brutal cracked and cratered surface and long considered as “completely inhospitable”. Now a shocking new theory suggests Mercury “chaotic terrain” may have been formed by volatiles.
These are elements and chemical compounds able to swiftly switch states underneath Mercury’s surface.
Such volatiles, such as water, are essential for life as we know it to exist.
Consequently, potential presence on Mercury is an exciting development for those hunting for alien life.
The study, led by Planetary Science Institute researcher Dr Alexis Rodriguez, examined Mercury’s chaotic terrain in closer detail.
The team suggest volatiles once shaped a planet with surface temperatures hot enough to melt lead.
Red planet Mars has a similarly chaotic terrain, but the landscape Earth’s nearest neighbour was likely caused by outflow channels.
With no such channels on Mercury, researchers instead tied the terrain to a powerful asteroid impact which left the Caloris basin, a massive crater still visible on the planet’s surface.
Until now, space experts believed Mercury’s chaotic terrain was created by earthquakes triggered on Mercury following the impact.
However, the new study, suggests this was not possible because of the unfeasible time scale.
Co-author Daniel Berman, also of the Planetary Science Institute, said: “A key to the discovery was the finding that the development of the chaotic terrains persisted until approximately 1.8 billion years ago, two billion years after the Caloris basin formed.”
This was the “first, kind of, smoking gun,” Dr Rodriguez told Space.com.
The researchers were able to date these features using data and images from the NASA MErcury Surface Space ENvironment GEochemistry and Ranging (MESSENGER) spacecraft.
“Instead of bringing down buildings you’re bringing down mountains … entire mountain ranges.”
The researchers suggest if earthquakes following the impact caused the chaotic terrain, then those smaller features wouldn’t have been preserved.
These observations informed the team’s findings that this previous notion about the chaotic terrain’s formation was flawed.