Science Feature

Saturn's Rainbow Rings

It may be pretty, but this image of Saturn's famous rings is also a boon for astronomers.

Taken by Cassini's infrared composite spectrometer, this false color image shows the unlit side of Saturn's rings according to temperature overlayed on a second image of Saturn and its ring system. They are the most detailed temperature measurements of the planet's rings to date.

Relatively warm areas - 110 Kelvin (-281 degrees Fahrenheit) - appear in red, with cooler regions - about 70 Kelvin (- 333 degrees Fahrenheit) show up blue. The green areas represent temperatures of 90 Kelvin (-298 degrees Fahrenheit).

Released this month, this image was taken on July 1 just after Cassini entered orbit around Saturn.

The temperature data shows many features scientists had only been able to predict, among them that opaque ring regions (such as the outer A ring on the far right) are cooler, while more transparent areas like the Cassini Division (the red inside the A ring) and C ring (the inner yellow and red area) are warmer. Researchers believe the opaque areas are cooler because they let less light through.

Saturn itself is over exposed in this image, leading to its white appearance. In addition to the planet and its rings, Cassini also spotted the Saturnian moon Enceladus in this observation. The moon appears below the rings towards the image's center.

-- SPACE.com Staff

This image from NASA's Terra satellite shows land surface temperatures during June 26 though July 3, 2007, compared to average temperatures observed during the same period in 2000, 2001, and 2002. Red indicates higher temperatures than previously recorded; blue indicates lower ones.

Deep red marks the extreme heat that lingered over much of the western United States in early July 2007. Skyrocketing temperatures met or broke records from Las Vegas, Nevada, to Great Falls, Montana, according to news reports. The oppressive heat created prime fire conditions, so when dry thunderstorms (lightning storms with little or no rain) occurred on July 7, lightning sparked dozens of fast-moving wildfires.

Northern California, Oregon, and Washington appear cooler than in previous years, as indicated by the blue areas. The heat wave started midway through the week-long period shown in this image. Although temperatures may have soared at the end of the period, cooler temperatures earlier in the week dominate the signal. Land surface temperatures from July 4-11 show that these areas warmed considerably the following week.

The Southern Plains are dark blue where temperatures fell lower than they had been in previous years. During this period, torrential rains soaked the region, causing widespread flooding in Texas and Oklahoma, and in Kansas and Missouri.

The gray portions of the image in Kansas and Oklahoma could not be surveyed by MODIS because of continuous cloud cover during the week-long period.