In the northern winter months we are surrounded by the stark beauty of chilled landscapes. From the darkness of the far north, broken perhaps only by starlight and the glow of aurora, to the brisk grey streets of Manhattan and its now skeletal trees with their claw-like limbs and knobbly stubs pressed to the skies, [...]
In the northern winter months we are surrounded by the stark beauty of chilled landscapes. From the darkness of the far north, broken perhaps only by starlight and the glow of aurora, to the brisk grey streets of Manhattan and its now skeletal trees with their claw-like limbs and knobbly stubs pressed to the skies, this is not a time of complexity or color.
In my winter funk, I find myself thinking that this must be what it would feel like to be among the outer planets, frigid and dimly lit by a distant Sun, where our senses would register little difference between winter and summer. Perhaps the most stunningly austere is Saturn. Despite its vast ring system and 62 moons, this giant world appears in visible light as a smooth and positively minimalist sculpture, emotionally cold and distant. However it is also extraordinarily beautiful. So, as a last thought before our Gregorian new year, here are some examples of Saturn's aloof majesty.
Saturn just past its equinox, imaged by the Cassini mission from a distance of 526,000 miles.
A giant and its brood. Titan seen above Saturn's rings, tiny Prometheus, Janus, and Mimas lurking closer to the equator. Giant shadows cast by the rings onto Saturn's upper atmosphere (NASA/JPL)
A tiny moon (Epimetheus, 72 miles across) is a little dim speck towards the center of the frame, vast Saturn looming over it (NASA/JPL/Cassini))
The haze enshrouded and frigid moon Titan, almost eclipsing icy Dione (itself the 3rd largest moon around Saturn) in the background. The shadows of Saturn's rings (seen horizontally across this image) play onto its atmosphere (NASA/JPL)
Some of Saturn's moons orbit close enough to the plane of the rings to cast long shadows at the time of equinox. In this case the culprit is Mimas, creating what looks like a tear in the fabric of space itself (NASA/JPL).
Uplit by the Sun and more generally by reflected sunlight from Saturn, the two moons Tethys (left) and Enceladus (right) appear to pass by each other. In reality Tethys is 162,000 miles further from Enceladus in this snapshot. Below Enceladus is a plume of water vapor being expelled hundreds of miles into space from its "cryo-geysers", a signature of what may be liquid water reservoirs beneath its ice crust.
Magnificent Saturn, subtle blue and gold tones, while its moon Dione circles in silence (NASA/JPL). The Sun's radiation is 100 times fainter out here than at the Earth, and Saturn's upper atmosphere can be as cold as -280 F.
The views expressed are those of the author(s) and are not necessarily those of Scientific American.
ABOUT THE AUTHOR(S)
Caleb A. Scharf
Dr. Caleb A. Scharf is Director of Astrobiology at Columbia University,and has an international reputation as a research astrophysicist, and asa lecturer to college and public audiences. The UK's Guardian newspaperhas listed his blog Life, Unbounded, as one of their "hottest scienceblogs," while an editor at Seed Magazine called it "phenomenal.Informed, fresh, and thoughtful." Scharf is author and co-author of morethan 100 scientific research articles in astronomy and astrophysics. Hiswork has been featured in publications such as New Scientist, ScientificAmerican, Science News, Cosmos Magazine, Physics Today, and National Geographic, as well as online at sites like Space.com and Physorg.com. His textbook for undergraduate and graduate students, Extrasolar Planets and Astrobiology, won the 2012 Chambliss Prize of the AAS. His articles and reviews have appeared in such prestigious publications as Science, Nature, The Astrophysical Journal, and Monthly Notices of the Royal Astronomical Society. Dr. Scharf is a regular keynote speaker at academic meetings, such as for the American Physical Society, museums, and both public and private venues, including the American Museum of Natural History and the Rubin Museum of Art in New York. He has been a guest on Krulwich on Science at NPR, William Shatner's "Weird or What?" and has served as a consultantt o editors and producers at National Geographic Magazine, The Science Channel, The Discovery Channel, and The New York Times.