KCRW ‘To The Point’ Interview: Cassini’s Grand Finale

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Artist’s impression of Cassini passing through the gap between Saturn and the planet’s rings (NASA/JPL-Caltech)

After all the excitement of last night’s Cassini mission checking in and transmitting data to NASA’s Deep Space Network, I joined Warren Olney on his NPR-syndicated show “To The Point” this morning to chat about the mission and why the “Grand Finale” is an awesome, yet bittersweet, part of Saturn exploration. Listen to the 10 minute segment here. It was great as always to chat with Warren, thanks for having me on the show!

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Cassini Survives First Saturn Ring Dive and Returns Historic Photos

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NASA/JPL-Caltech

UPDATE (1:30 a.m. PT): A firehose of Cassini data has opened up and raw images of the spacecraft’s approach to the ring plane are coming in at a rapid pace. You can see the raw images appear online at the same time Cassini’s science team sees them here. At time of writing (and without any scientific analysis) the images have been of Saturn’s polar vortex and various views of the planet’s upper atmosphere. It’s going to take some time for more detailed views to become available, but, wow, it’s exhilarating to see Cassini images arrive at such a rate. Here are a few:

Original: As NASA planned, just before midnight on Wednesday (April 26), the veteran Cassini spacecraft made radio contact with the Goldstone 70-meter antenna in California, part of the Deep Space Network (DSN), which communicates with missions in space. Within minutes, Goldstone was receiving data, meaning the spacecraft had not only survived its first ring dive of the “Grand Finale” phase of its mission, but that it was also transmitting science data from a region of space that we’ve never explored before.

“We did it! Cassini is in contact with Earth and sending back data after a successful dive through the gap between Saturn and its rings,” tweeted the official NASA Cassini account just after the DSN confirmed it was receiving telemetry.

“The gap between Saturn and its rings is no longer unexplored space – and we’re going back 21 times,” they added.

Around 22 hours prior to Cassini’s signal, the spacecraft made its daring transit through the gap between Saturn’s upper atmosphere and innermost ring after using the gravity of Titan on Friday (April 21) to send it on a ballistic trajectory through the ring plane. But during that time the spacecraft went silent, instead devoting resources to carrying out science observations during the dive.

Of course there was much anticipation for Cassini to “phone home” tonight and it did just that right on schedule and now we can look forward to another 21 dives through Saturn’s rings before Cassini burns up in the gas giant’s upper atmosphere on Sept. 15, ending its epic 13 year mission at the solar system’s ringed planet.

“No spacecraft has ever been this close to Saturn before. We could only rely on predictions, based on our experience with Saturn’s other rings, of what we thought this gap between the rings and Saturn would be like,” said Earl Maize, Cassini Project Manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in a statement. “I am delighted to report that Cassini shot through the gap just as we planned and has come out the other side in excellent shape.”

So now we wait until images of this never-before-explored region of Saturn are released.

Read more about Cassini’s historic ring dive in my Space.com interview with Cassini deputy project scientist Scott Edgington.

Cassini Says “Ciao!” to Pan, Saturn’s Ravioli Moon

Never before has a space probe come so close to the pint-sized moon embedded in Saturn’s rings — and when NASA’s Cassini buzzed Pan, the spacecraft revealed what a strange moon it really is.

NASA/JPL-Caltech/Space Science Institute

This is Pan, a 22 mile-wide moon that scoots through Saturn’s rings, orbiting the gas giant once every 13.8 hours. And it’s weird.

Resembling a giant ravioli or some kind of “flying saucer” from a classic alien invasion sci-fi comic, Pan is known as a “shepherd moon” occupying the so-called Encke Gap inside Saturn’s A Ring. This gap is largely free of particles and it has become Pan’s job to hoover up any stray material — the moon’s slight gravity pulls particles onto its surface and scatters others back out into the ring system. This gravitational disturbance creates waves that ripple through the ring material, propagating for hundreds of miles.

On March 7, NASA’s Cassini mission came within 15,268 miles of Pan, revealing incredible detail in the moon’s strange surface. It’s thought that its characteristic equatorial ridge (a trait it shares with another Saturn moon Atlas) is caused by the gradual accumulation of ring material throughout the moon’s formation and with these new observations, scientists will be able to better understand how Pan came to be.

NASA/JPL-Caltech/Space Science Institute

As Cassini rapidly approaches the end of its mission, eventually orbiting through Saturn’s ring plane as a part of its “Grand Finale,” we can expect more of these striking views from orbit before the veteran probe is steered into Saturn’s atmosphere in September, bringing its historic mission to an end.