'We think this is a very small amount of water': Here are the key takeaways from Nasa's Reddit AMA

In a major announcement on Monday, Nasa said Mars appears to have flowing rivulets of water — at least in the summer — a finding that boosts the odds of life on the red planet. “Mars is not the dry, arid planet that we thought of in the past,” said Jim Green, director of planetary science for Nasa. [caption id=“attachment_2448242” align=“alignleft” width=“380”] Representational image. Reuters[/caption] Scientists in 2008 confirmed the existence of frozen water on Mars. Now instruments aboard Nasa’s Mars Reconnaissance Orbiter have yielded what researchers said is the strongest evidence yet that water in its liquid form, trickles down certain Martian slopes. These results “strongly support the hypothesis” of liquid water on Mars on Monday, concluded a research paper published in the journal Nature Geoscience. Soon after the announcement, Nasa started an ‘Ask me anything’ (AMA) on Redit to answer the queries of people from around the world. The AMA was hosted by Rich Zurek (Chief Scientist, Nasa Mars Program Office; Project Scientist, Mars Reconnaissance Orbiter), Leslie K Tamppari (Deputy Project Scientist, MRO), Stephanie L Smith (Nasa-JPL social media team) and Sasha E Samonchina (Nasa-JPL social media team). Here are some key takeaways from the AMA : The water discovered on Mars is very little

We think this is a very small amount of water — maybe just enough to wet the top layer of the surface of Mars. The streaks are ~4-5 meters wide and ~200-300 meters long.

The current rovers are not designed to approach the site with water

These features (where water is observed) are on steep slopes, so our present rovers would not be able to climb up to them. Because liquid water appears to be present, these regions are considered special regions where we have to take extra precautions to prevent contamination by earth life. Our current rovers have not been sterilised to the degree needed to go to an area where liquid water may be present.

Only three percent of Mars’s surface has been photographed in high-definition for observation

The next step is to look for more locations where brine flows may occur. We have covered 3 percent of Mars at resolutions high enough to see these features.

Humans could be on Mars by late 2030s

Presently, Nasa is looking into the possibility of sending humans to the vicinity of Mars in the early 2030s. In this scenario, the earliest humans to the surface would be in the late 2030s.

So far, there is no way to determine the existence of life form on the planet

The Curiosity rover does not have life detection instruments. It would look for confirmation that liquid water was present and how long during the day it was liquid. We think liquid water is essential for life (at least as we know it.) That does not mean that life is there; but, it’s a good place to look.

The water comes from the ice on the planet, although the exact science behind the phenomenon is unclear

• New impact craters on Mars sometimes have bright ice exposed in the bottom of the crater. This goes away over a few months. The ice, when exposed, is going from solid to vapor. Evaporation of a briny flow will also occur, so the water needs to be resupplied. We don’t know how.
• The ice caps freeze and sublime (solid to vapor.) The RSL water stays liquid because it has salts in it. Yes, we know there’s water on Mars. We’re looking for where it stays liquid for an extended period of time.
• We don’t know where the water in these hydrated salts come from. That is the next mystery to solve! They leading hypotheses are that (1) the salts are sucking up the water from the atmosphere, but you are correct, there isn’t much water in the atmosphere, and (2) that the water is coming from the subsurface. There is certainly more to learn!

Nasa planning to send new lander on Mars in 2016, another rover in 2020s

We are planning to send the InSight lander to Mars in 2016, which will be lander designed to detect Mars-quakes. We also have a rover in development for the 2020s (same basic design as MSL/Curiosity) and Nasa is considering the science that might fly on the next Mars orbiter to be launched sometime after the 2020 rover.

Scientists are also artists

It takes all kinds of creative minds to do science and engineering that no one has ever done before. Among our mission teams, you’ll find actors, musicians, sculptors, painters – the list goes on. For visual artists, two individuals who spring to mind are Bill Hartmann ( http://www.psi.edu/about/staff/hartmann/painting.html ) and Dan Goods ( http://www.directedplay.com/ ).

Good food is served at Jet Propulsion Laboratory (JPL)

The food at JPL is actually quite good! Wood-fired pizza, burgers, sandwiches, good salad bar, etc.

Click here to read the entire AMA.