In April 1998, nearly a year before MGS reached its Primary Mission mapping orbit, several tests of the spacecraft's ability to be pointed at specific features was conducted with great success (e.g., Mars Pathfinder landing site, Viking 1 site, and Cydonia landforms). In this orientation, opportunities to hit a specific small feature of interest were in some cases rare, and in other cases non-existent. Throughout the Primary Mission (March 1999 - January 2001), nearly all MGS operations were conducted with the spacecraft pointing "nadir"-that is, straight down. A chance to point the spacecraft comes about ten times a week. It's currently trundling around Jezero Crater, where it's expected to encounter rocks as old as 3.6 billion years.A key aspect of the Mars Global Surveyor (MGS) Extended Mission is the opportunity to turn the spacecraft and point the Mars Orbiter Camera (MOC) at specific features of interest. So, if you want to go searching for signs of life, she added, your best bet is to target rocks from that era.Īnd that's what NASA's Perseverance rover is doing. "What we see is that all these minerals that incorporated this water into them all formed before 3 billion years ago," Ms Scheller said. In the search for life on Mars, it's not enough to know how Mars's water was lost we also need to know when. 'Seven minutes of terror': How hard it is to land on Mars.The blue sunsets are spectacular but the radiation bites.What happens now Perseverance has landed on Mars?.
'It won't be easy': NASA is officially looking for past life on Mars. There are glimpses of ancient Mars on present-day Earth. What's beneath Mars's surface remains largely a mystery for now. Some clays can hold around 13 per cent water, while others can have more than 30 per cent. Not all water-trapping minerals are created equal, either. "My approach would be to be a little bit cautious, and therefore maybe take the lower range of values for the total water mass," said Dr Caprarelli, who was part of a team that identified subsurface lakes near the planet's south pole. But how much wetter?"Įstimates for Mars's primordial water inventory can differ by an order of magnitude. "There is a lot of evidence that Mars was wetter initially, and I don't argue with that. "We show in our study that the combination of loss of water to sequestration and loss of water to space augments this effect," Ms Scheller said. Indeed, Curiosity rover discovered Mars's deuterium-to-hydrogen ratio is much higher than Earth's. Over time, as atmospheric hydrogen dwindles, the amount of deuterium relative to hydrogen increases. It also fits with what's known as the planet's deuterium-to-hydrogen ratio.ĭeuterium is a slightly heavier version of hydrogen - it has an extra neutron in its nucleus - and is less likely to escape into space. While Ms Scheller concedes the range is large, "it matches a bit better with what we were thinking from our geological data". That's up to three quarters of the volume of the Atlantic Ocean. The team's simulations suggest the Martian crust holds the equivalent of an ocean covering Mars to depths of between 100m and 1,000m. Without the ability to recycle its crust, much of the Red Planet's surface is billions of years old.Īnd it's these ancient rocks that are holding the better part of all that water that once graced the young Mars, according to the new study. On Mars, volcanic activity peaked between 3 and 4 billion years ago. Volcanic vents can then release those molecules as water vapour. Plate tectonics pushes huge swathes of crust down into the mantle layer below where it melts and releases water molecules from their crystalline strongholds. That's because Earth's surface is dynamic. This process, called weathering, takes place in Earth's crust too - but here, the water molecules aren't necessarily locked away for good.
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