Further evidence has emerged that Mars still has some liquid water

Scientists analysing images of Mars have found even more signs that, in rare circumstances, Mars may have water flowing across its surface.

Mars is supposed to be a dead, dry planet. There are clear signs that liquid water used to flow across its surface - remember Nasa mocking up that video of the Mars of 3.7 billion years ago? - but one of the Curiosity rover’s jobs right now is to investigate what we take to be ancient river bed.

This makes it very surprising indeed that scientists saw dark, water-like streaks in the red dust, in 2011. This should not be happening on a planet with no atmosphere.

To be clear, this isn’t proof that there’s liquid water on Mars - it’s just that we’ve seen something that looks a heck of a lot like liquid water. Here’s a slideshow of eight images showing what we’re talking about, provided by Nature:

Those black lines, as spotted by the Mars Reconnaissance Orbiter, are known as “recurring slope lineae”, and they darken the Martian soil just as water darkens soil on Earth. They were originally found two years ago at seven sites in the highlands of southern Mars, at middle latitudes which warm up in the summer and freeze again in the winter.

This latest study, by the same team of planetary scientists led by Alfred McEwen of the University of Arizona in Tucson, has found a further 12 sites with streaks, all on or near the equator. The equator has roughly the same temperatures year-round, and that means that - if there’s liquid water flowing on the surface - there must be a mechanism in place to replenish it. Mars’ low atmospheric pressure means that liquid water on the surface should sublimate into a gas almost immediately.

We now know that there’s quite a lot of water on Mars, be it frozen on the surface at the poles, under the surface elsewhere on the planet, or bound up with the soil itself. The implication of a flowing water source is that it might be the most likely location of life that still exists on Mars - but, conversely, that also makes it more crucial that we don’t send improperly sterilised probes there. If those Earth microbes are to survive anywhere on Mars - and scientists recently discovered a whole new species of microbe that could survive in even the most sterile of spaceship construction labs - then they’ll survive on these slopes.

It's also exciting for future colonists, who will save on energy if they don't have to heat up ice for drinking water. Our best chance of figuring out the exact nature of these lines on Mars is from afar, with the Mars Reconnaissance Orbiter, until we can decide what further action to take. Perhaps even the first colonisers, whoever they be (maybe it'll be Mars One, who want to send people there on a one-way mission starting from 2024) will be able to take advantage of that water source.

Dark streaks on Mars that may be water. (Image: NASA/JPL-Caltech/U. of Arizona)

Ian Steadman is a staff science and technology writer at the New Statesman. He is on Twitter as @iansteadman.

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SRSLY #45: Love, Nina, Internet Histories Week, The Secret in Their Eyes

This week on the pop culture podcast, we chat Nick Hornby’s adaptation of Nina Stibbe’s literary memoir, our histories on the internet, and an Oscar-winning 2009 Argentinian thriller.

This is SRSLY, the pop culture podcast from the New Statesman. Here, you can find links to all the things we talk about in the show as well as a bit more detail about who we are and where else you can find us online.

...or subscribe in iTunes. We’re also on StitcherRSS and SoundCloud – but if you use a podcast app that we’re not appearing in, let us know.

SRSLY is hosted by Caroline Crampton and Anna Leszkiewicz, the NS’s web editor and editorial assistant. We’re on Twitter as @c_crampton and @annaleszkie, where between us we post a heady mixture of Serious Journalism, excellent gifs and regularly ask questions J K Rowling needs to answer.

The Links

Love, Nina

The first episode on iPlayer.

An interview with Nina Stibbe about the book.

Internet Histories Week

The index of all the posts in the series.

Our conversation about MSN Messenger.

The Secret in Their Eyes

The trailer.

For next week

Anna is watching 30 Rock.

If you’d like to talk to us about the podcast or make a suggestion for something we should read or cover, you can email srslypod[at]gmail.com.

You can also find us on Twitter @srslypod, or send us your thoughts on tumblr here. If you like the podcast, we’d love you to leave a review on iTunes - this helps other people come across it.

We love reading out your emails. If you have thoughts you want to share on anything we’ve discussed, or questions you want to ask us, please email us on srslypod[at]gmail.com, or @ us on Twitter @srslypod, or get in touch via tumblr here. We also have Facebook now.

Our theme music is “Guatemala - Panama March” (by Heftone Banjo Orchestra), licensed under Creative Commons. 

See you next week!

PS If you missed #44, check it out here.