The rings of Saturn
Cool image time! The picture on right, cropped by me to show here, was taken by Cassini on April 2, 2016. You can see the moons Dione (on left) and Epimetheus (on right) above the rings. The full image can be seen here.
I am sure there is a lot of important science contained within this image. I post it here however not because of any scientific reason but entirely because it is simply damn spectacular. More than a decade after Cassini arrived at Saturn, every new picture of the planet’s giant ring system still seems incredibly unbelievable.
The universe is an amazing place, isn’t it?
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 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 picture on right, cropped by me to show here, was taken by Cassini on April 2, 2016. You can see the moons Dione (on left) and Epimetheus (on right) above the rings. The full image can be seen here.
I am sure there is a lot of important science contained within this image. I post it here however not because of any scientific reason but entirely because it is simply damn spectacular. More than a decade after Cassini arrived at Saturn, every new picture of the planet’s giant ring system still seems incredibly unbelievable.
The universe is an amazing place, isn’t it?
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 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
Ab-so-lutely, an amazing place!
I was thinking this morning, before seeing this image, how much we have learned about our solar system and its origin in my 67 year lifetime.
When I was a pup, long before the internet, I went to the library to get the most accurate information on planetary science. We also had a the multi-volume Encyclopedia Britannica in our home and I recall it had a single fuzzy ground based telescope image of Saturn. The encyclopedia spoke of Saturn having four rings, but my older brother had written in the margin “Three rings not four!”
How far we have come in our knowledge thanks to the skills of the engineers, scientists, managers that created Cassini and the three spacecraft that preceded it. Well done!
We are accustomed now to this magnificent display of intricate, multiple narrow rings, rather than the disks originally supposed. But when the complex structure was discovered by the first fly-by, everyone was amazed. At least, everyone except Arthur Clarke who described the numerous bands in his novel “2001” (which had its space travelers going to Saturn, not Jupiter). I think he actually compared it to the groves of a phonograph record. The novel was many years before the fly-by. How did Clarke know!
Shout-out to Bob Z. for mentioning our comments above on the John Bachelor Show tonight. The universe is an amazing place!
Bernie Hutchins wrote:
“But when the complex structure was discovered by the first fly-by, everyone was amazed. At least, everyone except Arthur Clarke who described the numerous bands in his novel “2001” … The novel was many years before the fly-by. How did Clarke know!”
Clark liked to write with scientific accuracy, so he likely did some research. I will speculate that he may have discovered James Clerk Maxwell:
https://en.wikipedia.org/wiki/Rings_of_Saturn#Ring_theory.2C_observations_and_exploration
“In 1859, James Clerk Maxwell demonstrated that the rings could not be solid or they would become unstable and break apart. He proposed that the rings must be composed of numerous small particles, all independently orbiting Saturn. … Maxwell’s proposal was proven to be correct in 1895 through spectroscopic studies of the rings carried out by James Keeler of Allegheny Observatory and Aristarkh Belopolsky of Pulkovo Observatory.”
Arthur Clark knew at least a little about orbits, as he is the one who invented the geostationary communication satellite in a letter he wrote in 1945.
http://lakdiva.org/clarke/1945ww/
“An ‘artificial satellite’ at the correct distance from the earth would make one revolution every 24 hours; i.e., it would remain stationary above the same spot and would be within optical range of nearly half the earth’s surface. Three repeater stations, 120 degrees apart in the correct orbit could give television and microwave coverage to the entire planet.”
Knowing a little about orbits — that objects in orbits closer to the planet orbit faster than those farther from it — may have helped Clark understand that solid rings around Saturn would be structurally unstable.