Just a week after Curiosity celebrated its first Martian year in Gale Crater and we have yet another milestone anniversary in Solar System exploration: as of 10:48 p.m. EDT tonight Cassini will have been in orbit around Saturn for a full decade!
“There are times when human language is inadequate, when emotions choke the mind, when the magnitude of events cannot properly be conveyed by the same syllables we use to navigate everyday life. The evening of June 30, 2004 was such a time.”
– Carolyn Porco, Cassini Imaging Team Leader, CICLOPS “Captain’s Log” on June 30, 2014
That’s ten years and over 2 billion miles of discoveries and explorations of our Solar System’s most majestic planet and its incredibly varied family of moons. Over the course of its primary mission and three extended missions, we have been able to get a close-up look at Saturn and its moons like never before, witnessing first-hand the changes that occur as their seasons change. What’s been discovered by the Cassini mission about Saturn has offered invaluable insight into the evolution of our entire Solar System, as well as planets that could be found elsewhere in our galaxy.
“Having a healthy, long-lived spacecraft at Saturn has afforded us a precious opportunity,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “By having a decade there with Cassini, we have been privileged to witness never-before-seen events that are changing our understanding of how planetary systems form and what conditions might lead to habitats for life.”
Launched on October 15, 1997, the Cassini-Huygens spacecraft established orbit around Saturn on June 30, 2004 (July 1, UTC).
The weather forecast for Titan? Cloudy, hazy, and cold — just like every other day! The image here is a color-composite made from raw data captured by Cassini during a flyby on April 7, 2014, and it shows a look at the two main features of Titan’s atmosphere: a thick orange “smog” made of organic compounds created by the breakdown of nitrogen and methane by UV light, and a wispy blue upper-level haze composed of complex hydrocarbons.
Cassini was approximately 19,076 miles (30,700 km) from Titan when these particular images were captured.
We’ve known for quite some time now that lakes of liquid methane and ethane exist on the frigid surface of Saturn’s overcast moon Titan. While the sheer presence of large amounts of liquid on another world is fascinating, one thing that’s particularly intrigued scientists about these hydrocarbon lakes is their uncanny stillness — in many radar images they appear to be literally as smooth as glass, with no indication of movement or wave action of any sort. And although liquid methane isn’t water and probably behaves differently, with Titan’s substantial atmosphere it only makes sense that some sort of waves would get kicked up across lakes so vast, even from the most moderate seasonal breezes.
Now, a research team led by Jason Barnes of the University of Idaho has released findings showing what might be wave action — however small — captured by instruments aboard NASA’s Cassini spacecraft during several Titan flybys. And with the summer season approaching, this just might mean it’s “surf’s up” on Titan!
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…
By now you probably know about the lakes of liquid hydrocarbons on Titan. Thanks to Cassini, we know that Saturn’s largest moon is the one other place in the solar system where liquid can be found in stable amounts on the surface, except that it’s not water like we have here on Earth, but rather liquid methane. (Thank you for not smoking!) Now, radar measurements by Cassini show that Titan’s lakes are nearly all found in one 600 x 1100-mile region around its north pole — a true “land o’lakes!”
The animation above, made up of colorized radar data acquired over the past 9 years that the spacecraft has been in orbit around Saturn, takes us on a flyover tour of Titan’s northern lakes region. Fasten your seat belts!
A combination of exceptionally clear weather, the steady approach of northern summer, and a poleward orbital path has given Cassini — and Cassini scientists — unprecedented views of countless lakes scattered across Titan’s north polar region. In the near-infrared mosaic above they can be seen as dark splotches and speckles scattered around the moon’s north pole. Previously observed mainly via radar, these are the best visual and infrared wavelength images ever obtained of Titan’s northern “land o’ lakes!”
(But don’t even think about going swimming in these lakes — they’re filled with liquid METHANE, nearly 300 degrees below zero!)