SCIENCE - Life in Our Solar System

"What two discoveries suggest about life in the solar system" PBS NewsHour 3/6/2015

Excerpt

SUMMARY:  Science correspondent Miles O’Brien joins Judy Woodruff to discuss two space stories that center around the search for life and how it began.  NASA’s Dawn spacecraft arrived in orbit around the dwarf planet Ceres, which scientists believe shows signs of life-sustaining water.  Meanwhile, new research found that Mars once had enough water to cover 20 percent of the planet.

JUDY WOODRUFF (NewsHour):  Let’s close out our Friday with the continuing search, not just for life, but for a better understanding of how life began.

There’s a connection in two space stories today.  This morning, NASA said its Dawn spacecraft arrived in orbit around the dwarf planet Ceres, a journey of more than 300 million miles that lasted more than seven years.  Ceres lies in an asteroid belt between Mars and Jupiter.

And, yesterday, new research found that Mars once had even more water than we realized, enough to cover 20 percent of the planet and larger than our Arctic Ocean.

We’re joined by science correspondent Miles O’Brien.

So, Miles, tell us, what are they looking for on this tiny planet?

MILES O’BRIEN (NewsHour):  Well, wherever you look in the world on our world and you see liquid water, you will find life.  It doesn’t matter where.  You can be in the hot acidic springs of Yellowstone or deep below the ocean in the darkest places.  If there’s liquid water and an energy source, there is life.

And so this is what ties these two stories together.  Dawn is arriving at Ceres.  And there is lots of evidence that Ceres has quite a bit of water, perhaps an ice crust, perhaps even water geysers.  A dwarf planet, Judy, has a molten core.  And so there is reason to believe that there’s heat beneath the surface, which means there could be liquid water, which means there could be things alive there which date back 4.5 billion years.

It’s kind of mind-boggling, but this is like a snowball that’s been in the deep freeze, but it has a liquid core.  And so understanding what’s going on there will tell us a lot about the origins of life here and maybe elsewhere.