A Saturn moon makes waves
Cool image time! The image above, taken on January 16, 2017 during one of Cassini’s ring-grazing passes as it enters its last year at Saturn, has been reduced and cropped to post here. It shows clearly the waves caused by the gravity of the moon Daphnis as its travels within a gap in the rings of Saturn.
Daphnis (5 miles or 8 kilometers across) orbits within the 42-kilometer (26-mile) wide Keeler Gap. Cassini’s viewing angle causes the gap to appear narrower than it actually is, due to foreshorteneing. The little moon’s gravity raises waves in the edges of the gap in both the horizontal and vertical directions.
The image also shows many details about Daphnis itself, including a ridge at its equator that is thought to be an accumulation of material gathered from the rings.
The strangeness of Saturn’s rings is well illustrated here. Though made up of many solid particles, as a group the rings act almost like liquid. Note for example the ring on the far side of Daphnis. Its edge gets pulled out slightly as the moon goes by, but then the gravity of the rest of the ring pulls it back.
The universe is a wonderful place, as it is. No need to make up stuff (such as faces on Mars or fake civilizations on the Moon), as our imagination is probably insufficient to match the weirdness that is really out there.
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
Cool image time! The image above, taken on January 16, 2017 during one of Cassini’s ring-grazing passes as it enters its last year at Saturn, has been reduced and cropped to post here. It shows clearly the waves caused by the gravity of the moon Daphnis as its travels within a gap in the rings of Saturn.
Daphnis (5 miles or 8 kilometers across) orbits within the 42-kilometer (26-mile) wide Keeler Gap. Cassini’s viewing angle causes the gap to appear narrower than it actually is, due to foreshorteneing. The little moon’s gravity raises waves in the edges of the gap in both the horizontal and vertical directions.
The image also shows many details about Daphnis itself, including a ridge at its equator that is thought to be an accumulation of material gathered from the rings.
The strangeness of Saturn’s rings is well illustrated here. Though made up of many solid particles, as a group the rings act almost like liquid. Note for example the ring on the far side of Daphnis. Its edge gets pulled out slightly as the moon goes by, but then the gravity of the rest of the ring pulls it back.
The universe is a wonderful place, as it is. No need to make up stuff (such as faces on Mars or fake civilizations on the Moon), as our imagination is probably insufficient to match the weirdness that is really out there.
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
Note for example the ring on the far side of Daphnis. Its edge gets pulled out slightly as the moon goes by, but then the gravity of the rest of the ring pulls it back.
Is it moving right to left? If so, it looks like it distorts the ring by pulling it toward the moon before it passes.
“our imagination is probably insufficient to match the weirdness that is really out there.”
Amen.