Space

April 26, 2013

NASA probe observes meteors colliding with Saturn’s rings

nasa-saturn
NASA’s Cassini spacecraft has provided the first direct evidence of small meteoroids breaking into streams of rubble and crashing into Saturn’s rings.

These observations make Saturn’s rings the only location besides Earth, the moon, and Jupiter where scientists and amateur astronomers have been able to observe impacts as they occur. Studying the impact rate of meteoroids from outside the Saturn system helps scientists understand how different planet systems in the solar system formed.

Our solar system is full of small, speeding objects. Planetary bodies frequently are pummeled by them. The meteoroids at Saturn range from about one-half inch to several yards (1 centimeter to several meters) in size. It took scientists years to distinguish tracks left by nine meteoroids in 2005, 2009 and 2012.

Details of the observations appear in a paper in the Thursday edition of Science.

Results from Cassini already have shown Saturn’s rings act as very effective detectors of many kinds of surrounding phenomena, including the interior structure of the planet and the orbits of its moons. For example, a subtle but extensive corrugation that ripples 12,000 miles (19,000 kilometers) across the innermost rings tells of a very large meteoroid impact in 1983.

“These new results imply the current-day impact rates for small particles at Saturn are about the same as those at Earth – two very different neighborhoods in our solar system, and this is exciting to see,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “It took Saturn’s rings acting like a giant meteoroid detector – 100 times the surface area of the Earth – and Cassini’s long-term tour of the Saturn system to address this question.”

The Saturnian equinox in summer 2009 was an especially good time to see the debris left by meteoroid impacts. The very shallow sun angle on the rings caused the clouds of debris to look bright against the darkened rings in pictures from Cassini’s imaging science subsystem.

“We knew these little impacts were constantly occurring, but we didn’t know how big or how frequent they might be, and we didn’t necessarily expect them to take the form of spectacular shearing clouds,” said Matt Tiscareno, lead author of the paper and a Cassini participating scientist at Cornell University in Ithaca, N.Y. “The sunlight shining edge-on to the rings at the Saturnian equinox acted like an anti-cloaking device, so these usually invisible features became plain to see.”

Tiscareno and his colleagues now think meteoroids of this size probably break up on a first encounter with the rings, creating smaller, slower pieces that then enter into orbit around Saturn. The impact into the rings of these secondary meteoroid bits kicks up the clouds. The tiny particles forming these clouds have a range of orbital speeds around Saturn. The clouds they form soon are pulled into diagonal, extended bright streaks.

“Saturn’s rings are unusually bright and clean, leading some to suggest that the rings are actually much younger than Saturn,” said Jeff Cuzzi, a co-author of the paper and a Cassini interdisciplinary scientist specializing in planetary rings and dust at NASA’s Ames Research Center in Moffett Field, Calif. “To assess this dramatic claim, we must know more about the rate at which outside material is bombarding the rings. This latest analysis helps fill in that story with detection of impactors of a size that we weren’t previously able to detect directly.”

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the Cassini-Huygens mission for NASA’s Science Mission Directorate in Washington. JPL designed, developed and assembled the Cassini orbiter and its two onboard cameras. The imaging team consists of scientists from the United States, England, France and Germany. The imaging operations center is based at the Space Science Institute in Boulder, Colo.




All of this week's top headlines to your email every Friday.


 
 

 
nasa-commercial-crew

Commercial Crew milestones met; partners on track for 2017 missions

NASA has taken another step toward returning America’s ability to launch crew missions to the International Space Station from the United States in 2017. The Commercial Crew Program ordered its first crew rotation mission fro...
 
 
boeing-space

Boeing awarded first-ever commercial human spaceflight mission

NASA issued a task order as part of Boeing’s $4.2 billion Commercial Crew Transportation Capability contract recently to include the company’s first-ever service flight to the International Space Station. The award ...
 
 
Photograph courtesy of NASA/JPL-Caltech

NASA’s Europa mission begins with selection of science instruments

Photograph courtesy of NASA/JPL-Caltech Bizarre features on Europa’s icy surface suggest a warm interior. This view of the surface of Jupiter’s moon Europa was obtained by NASA’s Galileo mission, and shows a color...
 

 
Photograph courtesy of NASA/JPL-Caltech/Lockheed Martin

NASA begins testing Mars lander in preparation for next mission to Red Planet

Photograph courtesy of NASA/JPL-Caltech/Lockheed Martin Engineers and technicians at Lockheed Martin Space Systems, Denver, run a test of deploying the solar arrays on NASA’s InSight lander. Photo taken April 30, 2015. Te...
 
 
Image courtesy of NASA/JPL-Caltech

NASA’s WISE spacecraft discovers most luminous galaxy in universe

Image courtesy of NASA/JPL-Caltech This artist’s concept depicts the current record holder for the most luminous galaxy in the universe. The galaxy, WISE J224607.57-052635.0, is erupting with light equal to more than 300 ...
 
 

Air Force launches hush-hush mini-shuttle into space

A mysterious space plane rocketed into orbit May 20, carrying no crew but a full load of technology experiments. The Air Force launched its unmanned mini-shuttle late morning, May 20. An Atlas V rocket lifted it up and out over the Atlantic. This is the fourth flight for the military research program, which is shrouded...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>