- The Chicago Astronomer -
Copyright 2004-2014 All rights reserved by Joseph Guzman Administrator/Founder/Chief Astronomer.
All text and images are the property of the original authors/artists and shall
not be used without permission.
Post by Chicago Astronomer Joe on Jul 12, 2005 21:24:05 GMT -6
Strange Hyperion Looks Like a Sponge
From Universe Today...
(Jul 12, 2005) NASA's Cassini spacecraft has gotten a good look at Saturn's unusually shaped moon Hyperion. It has many fresh craters, giving it a spongy looking appearance. Scientists estimate that the moon is only 60% as dense as water, which means that much of its interior must be completely empty space. The images were gathered during a recent Hyperion flyby, when Cassini came within 168,000 km (104,000) of the moon.
Post by Chicago Astronomer Joe on Oct 1, 2005 6:38:24 GMT -6
Great new image of "the Sponge"
Cassini made its first flyby of Saturn's moon Hyperion last week, and took this amazing photograph. The spacecraft got within 500 km (310 miles), and you can clearly see how unusual this spongy-looking moon is. Scientists think that Hyperion is little more than a pile of rubble, loosely held together by its own gravity because much of its mass is just empty space. Hyperion is only 266 kilometers (165 miles) across, has an irregular shape, and spins in a chaotic rotation.
Post by Chicago Astronomer Joe on Feb 4, 2006 6:38:01 GMT -6
Rough and Tumble Hyperion
Fri, 03 Feb 2006) Cassini captured this image of Saturn's moon Hyperion during a distant encounter in December, 2005. Hyperion is only 280 km (174 miles) across, and is covered with closely packed pits, giving it a spongy appearance. This photo was taken when Cassini was 228,000 kilometers (142,000 miles) from Hyperion.
The tumbling and irregularly shaped moon Hyperion hangs before Cassini in this image taken during a distant encounter in Dec. 2005. This still image is part of a movie sequence of 40 images taken over about two hours as Cassini sped past the icy moon (see the related movie).
Hyperion (280 kilometers, or 174 miles across) is covered with closely packed and deeply etched pits. The warming action of the Sun on water ice lying beneath a darkened layer of surface material apparently has deepened and exaggerated the depressions already created by impacts.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 23, 2005 at a distance of 228,000 kilometers (142,000 miles) from Hyperion and at a Sun-Hyperion-spacecraft, or phase, angle of 77 degrees. Resolution in the original image was about 1.4 kilometers (0.9 mile) per pixel. The image was magnified by a factor of two and contrast-enhanced to aid visibility.