Featured Research

from universities, journals, and other organizations

Galileo Flyby Reveals Callisto's Bizarre Landscape

Date:
August 24, 2001
Source:
National Aeronautics And Space Administration
Summary:
A spiky landscape of bright ice and dark dust shows signs of slow but active erosion on the surface of Jupiter's moon Callisto in new images from NASA's Galileo spacecraft.

A spiky landscape of bright ice and dark dust shows signs of slow but active erosion on the surface of Jupiter's moon Callisto in new images from NASA's Galileo spacecraft.

Related Articles


The pictures taken by Galileo's camera on May 25 from a distance of less than 138 kilometers, or about 86 miles, above Callisto's surface give the highest resolution view ever seen of any of Jupiter's moons.

"We haven't seen terrain like this before. It looks like erosion is still going on, which is pretty surprising," said James Klemaszewski of Academic Research Lab, Phoenix, AZ. Klemaszewski is processing and analyzing the Galileo Callisto imagery with Dr. David A. Williams and Dr. Ronald Greeley of Arizona State University, Tempe.

Callisto, about the same size as the planet Mercury, is the most distant of Jupiter's four large moons. Callisto's surface of ice and rock is the most heavily cratered of any moon in the solar system, signifying that it is geologically "dead." There is no clear evidence that Callisto has experienced the volcanic activity or tectonic shifting that have erased some or all of the impact craters on Jupiter's other three large moons.

The jagged hills in the new images may be icy material thrown outward from a large impact billions of years ago, or the highly eroded remains of a large impact structure, Williams said. Each bright peak of dust is surrounded by darker dust that appears to be slumping off the peak. Right: the Galileo spacecraft

"They are continuing to erode and will eventually disappear," Klemaszewski said. One theory for an erosion process is that, as some of the ice turns into vapor, it leaves behind dust that was bound in the ice. The accumulating dark material may also absorb enough heat from the Sun to warm the ice adjacent to it and keep the process going. The new images show areas where the sharp knobs have apparently eroded away, leaving a plain blanketed with dark material.

The close-up images show craters as small as about 3 meters across, or about 10 feet, though not as many as some predictions anticipated. One scientific goal from the high-resolution images is to see how many small craters are crowded onto the surface. Crater counts are one way to estimate the age of a moon's surface, and since Callisto has been so undisturbed by other geological processes, its cratering density is useful in calibrating the estimates for Jupiter's other moons.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, CA, manages Galileo for NASA's Office of Space Science, Washington, DC.

Additional information about Galileo's mission is available online at:

http://galileo.jpl.nasa.gov

The close-ups and the first complete Callisto global color picture from Galileo are available on the Internet at:

http://www.jpl.nasa.gov/images/callisto


Story Source:

The above story is based on materials provided by National Aeronautics And Space Administration. Note: Materials may be edited for content and length.


Cite This Page:

National Aeronautics And Space Administration. "Galileo Flyby Reveals Callisto's Bizarre Landscape." ScienceDaily. ScienceDaily, 24 August 2001. <www.sciencedaily.com/releases/2001/08/010824080606.htm>.
National Aeronautics And Space Administration. (2001, August 24). Galileo Flyby Reveals Callisto's Bizarre Landscape. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2001/08/010824080606.htm
National Aeronautics And Space Administration. "Galileo Flyby Reveals Callisto's Bizarre Landscape." ScienceDaily. www.sciencedaily.com/releases/2001/08/010824080606.htm (accessed October 26, 2014).

Share This



More Space & Time News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: China Launches Moon Orbiter

Raw: China Launches Moon Orbiter

AP (Oct. 24, 2014) China launched an experimental spacecraft Friday to fly around the moon and back to Earth in preparation for the country's first unmanned return trip to the lunar surface. (Oct. 24) Video provided by AP
Powered by NewsLook.com
China Prepares Unmanned Mission To Lunar Orbit

China Prepares Unmanned Mission To Lunar Orbit

Newsy (Oct. 23, 2014) The mission is China's next step toward automated sample-return missions and eventual manned missions to the moon. Video provided by Newsy
Powered by NewsLook.com
Russian Cosmonauts Kick Off Final Spacewalk of 2014

Russian Cosmonauts Kick Off Final Spacewalk of 2014

Reuters - US Online Video (Oct. 22, 2014) Russian cosmonauts Maxim Suraev and Alexander Samokutyaev step outside the International Space Station to perform work on the exterior of the station's Russian module. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins