Voice Off Screen: So the evolution of Mars from a warm and wet planet to the cold and dry desert
we see today is one of our solar system's biggest secrets
and shedding a little bit of light on that secret is NASA's MAVEN mission.
Here to tell us more about it from NASA's Goddard Space Flight Center in
Greenbelt, Maryland is NASA Scientist Dr. Jared Espley. Thank you
for joining us.
Thank You.
Voice Off Screen: So MAVEN is returning some exciting results on the martian atmosphere
what are we seeing?
So MAVEN is NASA's most recent Mars mission, its actually in orbit around the planet
right now. It's main purpose is to investigate what caused
most of the martian atmosphere to disappear over time.
What I really mean by that is that we know that ancient Mars was a warm, wet
and possibly habitable environment. Whereas modern Mars is
clearly a cold, dry, and desolate place. So the question we'd like to answer is
"how did that come to be?" and with MAVEN we have the instruments to actually directly observe
this. We're seeing that the solar wind, this thin stream of gas flowing out
from the sun, is actually washing over the martian atmosphere and blowing it away
bit by bit so that over billions of years its been lost in an interplanetary
space forever.
Voice Off Screen: Fascinating
So what role does atmosphereic loss play in Mars' ability to
support life?
So everywhere that we find with life on Earth its associated with water.
So the question really comes down to
"Where can we find the water at Mars?" and so as
we talked about we actually think that Mars used to have a lot of liquid water on it
surface, but we see only today dry riverbeds, dry lakes,
dry gullies so something had to have happened to cause the atmosphere
and the water to go away, so that water could have either flown off
into space, been driven away into space, or gone into the subsurface.
And with MAVEN we're starting to see it clearly was driven off into space at least
a part. And so we're able to start addressing that question of where the water went.
Where the atmosphere went, and therefore the potential for life at Mars.
Voice Off Screen: Now what is MAVEN telling us about the impact of the Sun
on the martian climate?
So like we just talked about the main culprit
we think at the moment is the solar wind to drive away the martian atmosphere
but one of the really interesting things of course is the Sun itself has these beautiful
solar storms, these filamentary archs
of high energy gas that come flowing off of the Sun that makes these solar
storms. And as these storms wash over the planet we wonder if they would be
they would be able to create even greater atmospheric loss than just a steady state solar
wind. So we're interested in studying the steady state solar wind and comparing it
to what the atmosphere does when the huge solar storms wash over the planet.
Voice Off Screen: Interesting. So now a recent NASA discovery has found
water on Mars' surface. So how do MAVEN's results help us
understand what has actually happened to water on the planet?
Right, so that was a really interesting result because it showed that there was thin films
of water that occur seasonally on Mars today. So liquid water today
on the surface of the planet. And then MAVEN is interested in the big picture question
of how water has evolved over time at Mars at a planet
ary scale. What happened to the water that carved the dry river beds that we see?
And so together with the results of tiny bits of liquid water available today
and it's history of water that we're getting from MAVEN and how it's been lost to space
mostly, which is starting to answer the big picture question of the evolution of
water at Mars.
Voice Off Screen: Where can we go to learn more
about MAVEN and NASA's future with Mars?
You can learn more at
nasa.gov/maven, there's all kinds of really cool science visualizations
and interesting videos about our mission and the results that we're getting.
Voice Off Screen: Dr. Jared Espley thank you so much for joining us.
Thank you.