Featured Research

from universities, journals, and other organizations

New Discovery At Jupiter Could Help Protect Earth-orbit Satellites

Date:
March 12, 2008
Source:
British Antarctic Survey
Summary:
Radio waves accelerate electrons within Jupiter's magnetic field in the same way as they do on Earth, according to new research. The discovery overturns a theory that has held sway for more than a generation and has important implications for protecting Earth-orbiting satellites.

This true color mosaic of Jupiter was constructed from images taken by the narrow angle camera onboard NASA's Cassini spacecraft on December 29, 2000, during its closest approach to the giant planet at a distance of approximately 10 million kilometers (6.2 million miles).
Credit: NASA/JPL/Space Science Institute

Radio waves accelerate electrons within Jupiter's magnetic field in the same way as they do on Earth, according to new research published in Nature Physics this week. The discovery overturns a theory that has held sway for more than a generation and has important implications for protecting Earth-orbiting satellites.

Related Articles


Using data collected at Jupiter by the Galileo spacecraft, Dr Richard Horne of British Antarctic Survey (BAS) and colleagues from the University of California, Los Angeles, and the University of Iowa found that a special type of very low frequency radio wave is strong enough to accelerate electrons up to very high energies inside Jupiter's magnetic field.

According to lead author, Dr Richard Horne, "We've shown before that very low frequency radio waves can accelerate electrons in the Earth's magnetic field, but we have now shown that exactly the same theory works on Jupiter, where the magnetic field is 20,000 times stronger than the Earth's and the composition of the atmosphere is very different. This is the ultimate test of our theory."

"On Jupiter, the waves are powered by energy from volcanoes on the moon Io, combined with the planet's rapid rotation -- once every 10 hours. Volcanic gasses are ionized and flung out away from the planet by centrifugal force. This material is replaced by an inward flow of particles that excite the waves that in turn accelerate the electrons."

Understanding how electrons are accelerated will help scientists make better predictions of when satellites are at risk of damage by high-energy charged particles. These particles encircle the Earth in the Van Allen radiation belts and can damage satellites by causing malfunctions and degrading electronic components. However, the number of particles in the radiation belts can change dramatically within a few minutes, which is why more accurate forecasting is needed.

The discovery also has other scientific implications for Jupiter -- it overturns a theory that has held sway for more than 30 years. According to Dr Horne,

"For more than 30 years it was thought that the electrons are accelerated as a result of transport towards Jupiter, but now we show that gyro-resonant wave acceleration is a very important step that acts in concert. Once the electrons are accelerated, they are transported closer to the planet and emit intense synchrotron radiation out into interplanetary space. Our theory provides the missing step to explain this high intensity radiation from Jupiter, which was first detected on Earth more than 50 years ago."

The paper 'Gyro-resonant electron acceleration at Jupiter', is published in Nature Physics on 9 March 2008.

Background information

Wave acceleration

The waves accelerate the electrons by a process known as gyro-resonance -- a process where the electrons spiral around the Earth's magnetic field at the same rate as the waves rotate around the magnetic field -- around 3,000 times a second, or 3 kiloHertz. The waves were found to be particularly strong outside the orbit of Jupiter's moon Io and are known as whistler mode chorus waves. The same waves are found in the Earth's magnetic field and are measured by BAS scientists in the Antarctic.

Van Allen radiation belts

Jupiter, like the Earth, has belts of energetic charged particles (electrons and ions) that surround the planet like a ring doughnut. They are named after James Van Allen who discovered the Earth's radiation belts 50 years ago using the first US satellite, Explorer I. Jupiter's belts were also discovered by Van Allen when Pioneer 10 flew past the planet in 1973 on its way to the outer planets. Jupiter's magnetic field constrains the particles to move in a spiral along the magnetic field. The particles 'bounce' between mirror points in the northern and southern hemispheres, and drift around the planet.

Galileo spacecraft

Launched by the space shuttle in October 1989, the NASA spacecraft Galileo was sent to explore Jupiter and its moons, reaching the planet in December 1995. Unfortunately the high-gain antenna failed to deploy properly and the spacecraft could only send a trickle of information back to Earth via its low-gain antenna. Nevertheless, several important new discoveries were made about Jupiter, its moons, magnetic field and particles. As a result, NASA is planning another mission, called Juno, which will study Jupiter's atmosphere, auroral light emissions, and magnetic field. Juno is due for launch in 2011.


Story Source:

The above story is based on materials provided by British Antarctic Survey. Note: Materials may be edited for content and length.


Cite This Page:

British Antarctic Survey. "New Discovery At Jupiter Could Help Protect Earth-orbit Satellites." ScienceDaily. ScienceDaily, 12 March 2008. <www.sciencedaily.com/releases/2008/03/080309151238.htm>.
British Antarctic Survey. (2008, March 12). New Discovery At Jupiter Could Help Protect Earth-orbit Satellites. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2008/03/080309151238.htm
British Antarctic Survey. "New Discovery At Jupiter Could Help Protect Earth-orbit Satellites." ScienceDaily. www.sciencedaily.com/releases/2008/03/080309151238.htm (accessed October 31, 2014).

Share This



More Space & Time News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Antares Liftoff Explosion

Raw: Antares Liftoff Explosion

AP (Oct. 29, 2014) Observers near Wallops Island recorded what they thought would be a routine rocket launch Tuesday night. What they recorded was a major rocket explosion shortly after lift off. (Oct 29) Video provided by AP
Powered by NewsLook.com
Raw: Russian Cargo Ship Docks at Space Station

Raw: Russian Cargo Ship Docks at Space Station

AP (Oct. 29, 2014) Just hours after an American cargo run to the International Space Station ended in flames, a Russian supply ship has arrived at the station with a load of fresh supplies. (Oct. 29) Video provided by AP
Powered by NewsLook.com
Journalist Captures Moment of Antares Rocket Explosion

Journalist Captures Moment of Antares Rocket Explosion

Reuters - US Online Video (Oct. 29, 2014) A space education journalist is among those who witness and record the explosion of an unmanned Antares rocket seconds after its launch. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
Rocket Explosion Under Investigation

Rocket Explosion Under Investigation

AP (Oct. 28, 2014) NASA and Orbital Sciences officials say they are investigating the explosion of an unmanned commercial supply rocket bound for the International Space Station. It blew up moments after liftoff Tuesday evening over the launch site in Virginia. (Oct. 28) Video provided by AP
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