It’s been suspected for nearly a decade that Saturn’s 315-mile-wide moon Enceladus harbors a hidden ocean beneath its frozen crust, thanks to observations by the Cassini spacecraft of icy plumes spraying from its southern pole, and now scientists have even more evidence supporting its existence: Doppler measurements of the moon’s gravity taken during Cassini’s flybys show variations indicative of a subsurface southern sea as deep as the Pacific’s Mariana Trench!
What a year for space exploration! With 2013 coming to a close I thought I would look back on some of the biggest news in space that I’ve featured here on Lights in the Dark. Rather than a “top ten” list, as is common with these year-end reviews, I’m going to do more of a month-by-month (hence the 12) to help recollect some of the amazing stories and sights that 2013 has brought us. And with some of the big headliners we’ve seen this year it’s easy to lose sight of the smaller (but no less fascinating) discoveries — so I’ll be sure to include some of those too. After all, when it comes to learning about the Universe there’s no “little” news!
Ready? Let’s go!
Cassini couldn’t make it to the mall this year to do any Christmas shopping but that’s ok: we all got something better in our stockings than anything store-bought! To celebrate the holidays the Cassini team has shared some truly incredible images of Saturn and some of its many moons for the world to “ooh” and “ahh” over. So relax, sit back and marvel at some sights from a wintry wonderland 900 million miles away…
Earth may display its seas on its surface for all the Universe to see, but further out in the Solar System liquid oceans are kept discreetly under wraps, hidden beneath cratered surfaces of ice and rock. And while Saturn’s moon Enceladus sprays its salty subsurface ocean out into space, other moons are less ostentatious — Europa, Ganymede, Titan… all are thought to have considerable underground oceans of liquid water, based on measurements of their mass, density, and shape.
Now, scientists are suggesting that Saturn’s 700-mile-wide moon Dione may also have a subsurface ocean… and may have even once exhibited icy geysers like its smaller sibling Enceladus.
Thanks to Cassini we’ve known about the jets of icy brine spraying from the south pole of Saturn’s moon Enceladus for about 8 years now, but this week it was revealed at the 44th Lunar and Planetary Science Conference outside Houston, Texas that Enceladus’ jets very likely reach all the way down to the sea — a salty subsurface sea of liquid water that’s thought to lie beneath nearly 10 kilometers of ice.
“To touch the jets of Enceladus is to touch the most accessible salty, organic-rich, extraterrestrial body of water and, hence, habitable zone, in our solar system.”
– Cassini imaging team leader Carolyn Porco
Enceladus, Saturn’s 318-mile-wide moon that’s become famous for its ice-spraying southern jets, is on astronomers’ short list of places in our own solar system where extraterrestrial life could be hiding — and on March 27, NASA’s Cassini spacecraft was in just the right place to try and sniff it out.
Why does Cassini team director Carolyn Porco think Enceladus is THE place in the solar system where we are most likely to find life? Find out here.