It’s official: Cassini’s mission at Saturn is over. Today, at 6:31 a.m. EDT (10:31 UTC), Cassini entered the atmosphere of Saturn. A little over a minute later it sent its final transmission back to Earth before succumbing to the physical forces of entry. That signal, Cassini’s last piece of data, ended at 7:55 a.m. EDT (11:55 UTC). After over thirteen years in orbit Cassini is now a part of Saturn; its work is done.
About 14 hours earlier Cassini transmitted its final images of Saturn to Earth. You can see some of those below: Read the rest of this entry
Well, the day has come. Today is the last full day that NASA’s Cassini spacecraft will exist, and in fact right now it is on its final path—a grand soaring arc that will send it down into the atmosphere of Saturn itself on the morning of Friday, Sept. 15. It will be the closest to the ringed planet any spacecraft will have ever gotten, but it’s a trip that Cassini will not long survive. It’s the long-planned end of a glorious mission of exploration and discovery—not to mention beauty, art, and inspiration—and while Cassini itself will soon be gone, the enormous amount of data it has gathered in the twenty years since its launch will continue to drive discovery for many, many years to come.
(At least that’s what we’re all telling ourselves to make the loss a bit easier to bear.)
This has to be my favorite photo I captured during the August 21 solar eclipse from Charleston, SC. It shows a phenomenon called Baily’s Beads, which is caused by the last bits of Sun peeking through low points and between mountains along the limb of the Moon in the final moments before 100% totality. They’re only visible for a few seconds between the “diamond ring” effect (which I did not capture) and the appearance of the Sun’s outer corona, and I’m very happy to have caught them on camera!
From a “mere” 93 million miles away we’re able to view the surface of our home star the Sun very well with telescopes on Earth and in space…you can even observe large sunspots with your unaided eye (with proper protection, of course.) But the surface details of other stars tens, hundreds, or thousands of light-years away can’t be so easily resolved from Earth. The details are just too fine and get lost in the brilliance of the stars themselves.
But astronomers have now produced the best image yet of the surface of another star beyond our Solar System. Using the European Southern Observatory’s Very Large Telescope Interferometer, located on a high plateau in Chile’s Atacama Desert where the sky is some of the clearest and driest in the world, a team of scientists have mapped the movement of material in the atmosphere of Antares, a red supergiant star 700 times the size of our Sun that shines brightly in the heart of the constellation Scorpius. The observations enabled them to determine how material moves through Antares’ atmosphere and then construct an image of the star itself—the most accurate representation of another star besides the Sun.
Yes, it’s true. As of today, August 15, NASA’s Cassini spacecraft has less than 31 days—one full month—left in operation and, sadly, its existence. On September 15, 2017, Cassini will end its mission with a controlled dive into Saturn’s atmosphere…a journey that it will not long survive. But up until the very end Cassini, which has been exploring the majestic ringed planet and its family of moons since it arrived in the summer of 2004, will be making scientific observations and sending the data back to us here on Earth—at least as long as it possibly can. That data, in fact, will still be en route across the 900 million miles of space between us and Saturn for almost an hour after the spacecraft will have succumbed to the forces of atmospheric entry.
When Cassini’s final signal is received on Earth it will be a ghost message, sent from a ship that no longer exists.