September 21st, 2011
01:25 PM ET

A Quintet of Saturn's Moons

"A quintet of Saturn's moons come together in the Cassini spacecraft's field of view for this portrait.

Janus (179 kilometers, or 111 miles across) is on the far left. Pandora (81 kilometers, or 50 miles across) orbits between the A ring and the thin F ring near the middle of the image. Brightly reflective Enceladus (504 kilometers, or 313 miles across) appears above the center of the image. Saturn's second largest moon, Rhea (1,528 kilometers, or 949 miles across), is bisected by the right edge of the image. The smaller moon Mimas (396 kilometers, or 246 miles across) can be seen beyond Rhea also on the right side of the image.

This view looks toward the northern, sunlit side of the rings from just above the ringplane. Rhea is closest to Cassini here. The rings are beyond Rhea and Mimas. Enceladus is beyond the rings.

The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on July 29, 2011. The view was acquired at a distance of approximately 1.1 million kilometers (684,000 miles) from Rhea and 1.8 million kilometers (1.1 million miles) from Enceladus."

Source: NASA

Filed under: Light up the screen
September 21st, 2011
01:05 PM ET

26 pieces of falling satellite likely to survive plunge, NASA says

(CNN) - A satellite whose orbit is degrading is likely to crash back to Earth on Friday, and 26 pieces have a good chance of surviving the heat of re-entry, NASA said Wednesday.

Despite being pretty sure that the Upper Atmosphere Research Satellite, or UARS, will re-enter the atmosphere sometime Friday, U.S. time, Mark Matney of NASA's Orbital Debris team told CNN there is no way to know where it will fall.

Because the satellite travels thousands of miles in a matter of minutes, Matney said, even minutes before re-entry it will be impossible to pinpoint an exact location. On top of that, he said, "part of the problem is the spacecraft is tumbling in unpredictable ways and it is very difficult to very precisely pinpoint where it's coming down even right before the re-entry."

NASA says most of the six-ton spacecraft is made of aluminum, which has a relatively low melting temperature and will burn up on re-entry. But about half a ton of material is likely to make it through.

You can track UARS here.

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Filed under: In Space • News


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