The Origin of Saturn's Moon Phoebe: New Insights from NASA's Cassini Probe

[Orion1]

The debate about the origin of Saturn's moon Phoebe is over. While it may look like an asteroid, the tiny moon actually is an icy interloper from the distant fringes of the solar system, according to new results from NASA's Cassini probe.

Phoebe is "a frozen time capsule" from 4 billion years ago, "waiting for Cassini to come along and open it up," scientist Torrence Johnson said Wednesday in Pasadena, Calif.

Scientists made their determination based on spectroscopic measurements of Phoebe taken when Cassini swooped within 1,280 miles of the battered and beaten moon on June 11.

The images and measurements taken during the fly-by indicate that Phoebe is lighter than rock but heavier than ice -- similar in density to Pluto and its moon Triton. That suggests Phoebe has the same origin as those bodies on the outer edge of the solar system.

Spectroscopic data indicates that Phoebe's surface is made of water ice, water-bearing minerals, carbon dioxide, possible clays, said Roger Clark of the U.S. Geological Survey.

Infrared measurements indicate Phoebe's surface is very cold, about 110 degrees above absolute zero -- minus 261 degrees Fahrenheit -- in sunlight, according to John Pearl of the National Aeronautics and Space Administration's Goddard Space Flight Center in Greenbelt, Md. On the night side of the moon, the temperature drops to minus 325 degrees.

Reference:
http://www.jpl.nasa.gov/images/cassini/2004-06-13/pia06067-540-400.jpg
http://www.nasa.gov/mission_pages/cassini/media/media_images_archive_1.html
http://www.sltrib.com/2004/jun/06242004/nation_w/178530.asp

 

[AndyW]

Hello,

Thank you for sharing this information about Saturn's moon Phoebe. I find these new results from NASA's Cassini probe to be very interesting and significant. It is always exciting to learn more about the origins of celestial bodies in our solar system.

The spectroscopic measurements taken by Cassini during its fly-by of Phoebe provide strong evidence that the moon is an icy interloper from the distant fringes of the solar system. This is a fascinating discovery, as it suggests that Phoebe is a "frozen time capsule" from 4 billion years ago, waiting to be studied and understood.

The data also indicates that Phoebe's surface is made of water ice, water-bearing minerals, carbon dioxide, and possible clays. These findings are consistent with other bodies on the outer edge of the solar system, such as Pluto and its moon Triton. This supports the theory that Phoebe has a similar origin as these bodies.

It is also interesting to note the extreme temperatures on Phoebe's surface, reaching as low as minus 325 degrees Fahrenheit on the night side of the moon. This highlights the extreme conditions that exist in the outer regions of our solar system.

Overall, these new results from Cassini provide valuable insights into the origin and composition of Phoebe. I look forward to further studies and discoveries as we continue to explore and learn more about our solar system. Thank you for sharing this exciting news.