Mars used to be covered in water and so could have been ideal for supporting life, according to Nasa scientists.
Researchers found that the planet was once covered in more water than Earth is now, by working out the amount of water that has since been lost to space. About 4.3 billion years ago, half of the northern hemisphere of Mars was covered in water, with the ocean more than a mile deep in some places.
“Our study provides a solid estimate of how much water Mars once had, by determining how much water was lost to space,” said Geronimo Villanueva, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the new paper. “With this work, we can better understand the history of water on Mars.”
The new data changes the idea of Mars as an inhospitable desert planet that has been unable to support life, as it is now. The lack of water on the planet has long been seen as a reason that Mars is uninhabited, but the planet may have been much more welcoming when it was young.
As recently as ten years ago, scientists thought that while Mars had some water it mostly came forth sporadically, and did not cover much of the planet. But scientists have discovered that much more water than expected has been lost from Mars, changing the idea of what it would have been like.
“With Mars losing that much water, the planet was very likely wet for a longer period of time than was previously thought, suggesting it might have been habitable for longer,” said Michael Mumma, a senior scientist at Goddard and an author of a paper on the findings, published in Science.
The researchers were able to estimate the amount of water lost using observations made by the Very Large Telescope at the European Southern Observatory. That told scientists how much water — as well as a variation on water — was on Mars, which they could then compare with the amount of water in a Mars meteorite from 4.5 billion years ago.
Where to explore in the solar system
Where to explore in the solar system
1/10 Mars - Olympus Mons
Olympus Mons is the largest volcano in the Solar System. At 22km high Olympus Mons is nearly three times as high as Mt Everest
2/10 Mars - Mount Sharp
Mount Sharp is the current focus point of the Mars Science Laboratory’s Curiosity rover. Sitting at the forefront of Martian research this location will hopefully unlock the secrets of Mars’s past.
3/10 Ida and Dactyl
Nestled deep within the asteroid belt is the asteroid 243 Ida. During a fly by of the Galileo space probe it was discovered that Ida had a companion. Orbiting around Ida was a tiny moon that was named Dactyl.
4/10 Jupiter - The Red Spot
Getting tired of leisurely cruises through the Caribbean? Why not float a dirigible through one of the oldest known storms in the Solar System. Jupiter’s Great Red Spot is large enough to contain three Earths and has been present for over 300 years.
5/10 Moon - Sea of Tranquility
As the landing site of the first ever humans to set foot on the Moon who wouldn’t want to walk in the footsteps on Neil Armstrong on the Sea of Tranquility?
6/10 Europa - Underwater seas
Europa’s underwater seas are one of the strongest candidates for potential life outside Earth. Scientists are waiting the day we can probe their icy depths.
7/10 Titan - Methane Lakes
Saturn’s Moon Titan is home to a nice thick atmosphere. Similar to the Earth it supports a full weather cycle. Unlike the Earth, rather than using water, Titan’s cycle is based on methane, often found in gas cookers here on Earth.
8/10 Mimas, the Death Moon
What better location for a holiday snap. The large Herschel crater on Mimas gives this moon an appearance of a certain dark lords ultimate weapon. When viewed from the right angle it appears that the Death Star is in orbit around Saturn.
The thick clouds of Venus make it an extremely mysterious place. It also has some of the most extreme weather we can find. Runaway greenhouse gases have shrouded the planet in a thick layer of cloud, heating it to nearly 600°C. It is also home to sulphuric acid rain and crushing atmospheric pressure. Make sure you pack a sturdy umbrella!
10/10 Oceans of Earth
One of the most unexplored places in the Solar System is our own oceans. 70% of the Earth is covered in ocean and as of yet we have only explored around 10% of them. With so much water to explore who knows what we may find lurking in the depths.
They also mapped the amount of water over time, allowing them to work out how it changes over years and seasons.
Scientists hope to learn yet more about Mars’ climate and environment through Nasa’s Mars Exploration Program. Nasa and the European Space Agency both have rovers headed to the planet in coming years, which will carry new instruments and tools to conduct research on the planet.