Close-up of Helene, one of Saturn’s many many moons
Helene, as seen by Cassini in 2011
Cool image time! Though the Saturn orbiter Cassini is long gone, having been sent into Saturn’s atmosphere to burn up in 2017, its image archive of magnificent pictures is still available to peruse. To encourage others to do so, NASA today issued a series of press releases, listing the spacecraft’s top ten pictures from 2011, 2012, 2013, 2014, and 2015.
The picture to the right, cropped, reduced, and sharpened to post here, comes from the 2011 collection and was taken on June 18, 2011. It shows a close-up of 21-mile-wide Helene, one of Saturn’s many many moons and only discovered in 1980. Back in 2010 I featured another Cassini image of Helene, but that picture did not reveal the small surface features seen in the photo to the right.
The light and dark streaks probably indicate dust flowing downhill on the surface. Though the gravity of this object is tiny, it will be enough for dust to act like almost like a liquid, flowing down grade and then pooling in the central pond at the lowest point near the center of the picture. That process is so much like liquid flowing that it appears to have even eroded gullies on slopes near the top and bottom of the picture.
Side note: NASA’s “Science Editorial Team” also issued a press release today that falsely and ignorantly claimed these releases were “to celebrate 10 years since arriving at Saurn,” implying that Cassini arrived in 2013 and is still functioning.
The problem is that Cassini arrived in orbit around Saturn in 2004 and as I noted above ended its mission in 2017. It thus appears that the NASA Science Editorial Team is unable to do even one five-second web search to find out what really happened.
Just another data point indicating the dark age we now live in.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Helene, as seen by Cassini in 2011
Cool image time! Though the Saturn orbiter Cassini is long gone, having been sent into Saturn’s atmosphere to burn up in 2017, its image archive of magnificent pictures is still available to peruse. To encourage others to do so, NASA today issued a series of press releases, listing the spacecraft’s top ten pictures from 2011, 2012, 2013, 2014, and 2015.
The picture to the right, cropped, reduced, and sharpened to post here, comes from the 2011 collection and was taken on June 18, 2011. It shows a close-up of 21-mile-wide Helene, one of Saturn’s many many moons and only discovered in 1980. Back in 2010 I featured another Cassini image of Helene, but that picture did not reveal the small surface features seen in the photo to the right.
The light and dark streaks probably indicate dust flowing downhill on the surface. Though the gravity of this object is tiny, it will be enough for dust to act like almost like a liquid, flowing down grade and then pooling in the central pond at the lowest point near the center of the picture. That process is so much like liquid flowing that it appears to have even eroded gullies on slopes near the top and bottom of the picture.
Side note: NASA’s “Science Editorial Team” also issued a press release today that falsely and ignorantly claimed these releases were “to celebrate 10 years since arriving at Saurn,” implying that Cassini arrived in 2013 and is still functioning.
The problem is that Cassini arrived in orbit around Saturn in 2004 and as I noted above ended its mission in 2017. It thus appears that the NASA Science Editorial Team is unable to do even one five-second web search to find out what really happened.
Just another data point indicating the dark age we now live in.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Hummmm. The link to the press release does not seem to work. Perhaps NASA is making a few adjustments to it.
This is a neat shot.
This is a very cool shot.
I looked at the Wikipedia listing for this moon and it has an animation for this and two other moons of Saturn
https://en.wikipedia.org/wiki/Helene_(moon)
The article notes that the moon is at L4 (Lagrange point). This provides the moo n with a unique orbit (as I see it) that may explain the streaks on the surface. If you watch the animation at the top of the article the orbit is truly quite unique as it does not fully move around the planet. This is probably a Lagrange characteristic kind of as I expected.
The interesting thing to note is the double oscillatory nature of the orbit. – see the animation.
I think this motion may be at least partially a source for the streaks. With this type of orbit, I wonder what stresses an artificial satellite may experience in such an orbit.