Featured Research

from universities, journals, and other organizations

Telling time on Saturn: Undergraduate student shows how planet's magnetosphere changes with the seasons

Date:
May 3, 2013
Source:
University of Iowa
Summary:
An undergraduate student has discovered that a process occurring in Saturn's magnetosphere is linked to the planet's seasons and changes with them, a finding that helps clarify the length of a Saturn day and could alter our understanding of the Earth's magnetosphere.

A University of Iowa undergraduate student has discovered that a process occurring in Saturn's magnetosphere is linked to the planet's seasons and changes with them, a finding that helps clarify the length of a Saturn day and could alter our understanding of Earth's magnetosphere.
Credit: Image courtesy of NASA

A University of Iowa undergraduate student has discovered that a process occurring in Saturn's magnetosphere is linked to the planet's seasons and changes with them, a finding that helps clarify the length of a Saturn day and could alter our understanding of Earth's magnetosphere.

Related Articles


Saturn's magnetosphere is the third largest structure in the solar system, eclipsed only by the magnetic fields of the sun and Jupiter. Unlike Earth, which has a visible rocky surface and rotates once every 24 hours, Saturn is composed mostly of clouds and liquid gas layers, each rotating about the planet at its own rate of speed. This variation in rotation made it difficult for scientists to pin down time for the planet.

Decades ago, a strong and naturally occurring radio signal, called Saturn kilometric radiation (SKR), was believed to give an accurate measurement of a Saturn day. But data gathered by an ESA/NASA spacecraft proved otherwise.

Now, using data from NASA's Cassini spacecraft, which entered orbit around Saturn in 2004, UI space physicist Donald Gurnett and other scientists showed that the north and south poles have their own SKR "days" that vary over periods of weeks and years. How these different periods arise and are driven through the magnetosphere has become a central question of the Cassini mission, according to NASA officials.

The discovery by Tim Kennelly, a UI junior majoring in physics and astronomy, is one of the first direct observations of seasonal changes in Saturn's magnetosphere. In addition, the finding carries over to all planets having a magnetosphere, including Earth.

"I'm pleased to have contributed to our understanding of Saturn's magnetosphere so early in my career," says Kennelly, the lead author of the paper published online in the American Geophysical Union's (AGU) Journal of Geophysical Research. "I hope this trend continues."

Scientists have known for some time that Saturn's magnetospheric processes are linked together, from the activity generating the SKR emission relatively near the planet to the periodic signatures in Saturn's magnetosphere stretching millions of miles downstream in the planet's magnetotail. But they didn't know how they were linked.

Kennelly analyzed phenomena recorded between July 2004 and December 2011 by Cassini's UI-built Radio and Plasma Wave Science (RPWS) instrument and came to some novel conclusions about how the events are linked. First, he looked at inward-moving "flux tubes" composed of hot, electrically charged gas, called plasma. Focusing on the tubes when they initially formed and before they had a chance to dissipate under the influence of the magnetosphere, he found that the occurrence of the tubes correlates with activity in the northern and southern hemisphere depending upon the season.

Kennelly found that during winter in the northern hemisphere, the occurrence of flux tubes correlates with SKR period originating in the northern hemisphere. A similar flux tube and SKR correlation was noted for the southern hemisphere during southern winter. The events are strongly ordered, he says, and follow Saturn's seasonal changes.

This finding may alter how scientists look at Earth's magnetosphere and the Van Allen radiation belts that affect a variety of activities at Earth ranging from space flight safety to satellite and cell phone communications.

Commenting on his research experience, Kennelly says, "I'm really happy with the support I've received from Don Gurnett's group. They let me do a lot of the research on my own. I'm really appreciative." He adds that he will begin applying to graduate schools next semester and plans to earn his doctorate in plasma physics.

In addition to Kennelly, UI researchers include UI postdoctoral scholar Jared Leisner, associate research scientist George Hospodarsky and Donald Gurnett, head of the RPWS instrument investigation and the James A. Van Allen/Roy J. and Lucille A. Carver Professor of Physics and Astronomy.


Story Source:

The above story is based on materials provided by University of Iowa. The original article was written by Gary Galluzzo. Note: Materials may be edited for content and length.


Journal Reference:

  1. T. J. Kennelly, J. S. Leisner, G. B. Hospodarsky, D. A. Gurnett. Ordering of injection events within Saturnian SLS longitude and local time. Journal of Geophysical Research: Space Physics, 2013; 118 (2): 832 DOI: 10.1002/jgra.50152

Cite This Page:

University of Iowa. "Telling time on Saturn: Undergraduate student shows how planet's magnetosphere changes with the seasons." ScienceDaily. ScienceDaily, 3 May 2013. <www.sciencedaily.com/releases/2013/05/130503094951.htm>.
University of Iowa. (2013, May 3). Telling time on Saturn: Undergraduate student shows how planet's magnetosphere changes with the seasons. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2013/05/130503094951.htm
University of Iowa. "Telling time on Saturn: Undergraduate student shows how planet's magnetosphere changes with the seasons." ScienceDaily. www.sciencedaily.com/releases/2013/05/130503094951.htm (accessed March 3, 2015).

Share This


More From ScienceDaily



More Space & Time News

Tuesday, March 3, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: SpaceX Launches Rocket, Satellites on Board

Raw: SpaceX Launches Rocket, Satellites on Board

AP (Mar. 2, 2015) — SpaceX launched it&apos;s 16th Falcon 9 rocket from Cape Canaveral, Florida on Sunday night. The rocket was carrying two commercial communications satellites. (March 2) Video provided by AP
Powered by NewsLook.com
NASA EDGE: SMAP Launch

NASA EDGE: SMAP Launch

NASA (Mar. 2, 2015) — Join NASA EDGE as they cover the launch of the Soil Moisture Active Passive (SMAP) spacecraft live from Vandenberg Air Force Base.  Special guests include NASA Administrator Charlie Bolden, SMAP Project System Engineer Shawn Goodman and Lt Col Brande Walton and Joseph Sims from the Air Force.  No word on the Co-Host&apos;s whereabouts. Video provided by NASA
Powered by NewsLook.com
Astronauts Leave Space Station for Third Spacewalk

Astronauts Leave Space Station for Third Spacewalk

Reuters - News Video Online (Mar. 1, 2015) — NASA Commander Barry Wilmore and Flight Engineer Terry Virts perform their third spacewalk in eight days outside the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Spacesuit Water Leaks Not An Issue On Latest ISS Walk

Spacesuit Water Leaks Not An Issue On Latest ISS Walk

Newsy (Mar. 1, 2015) — Astronauts are ahead of schedule with hardware upgrades to the International Space Station, despite last week&apos;s spacesuit water leak scare. 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