Featured Research

from universities, journals, and other organizations

Comet Collides With Solar Hurricane

Date:
October 1, 2007
Source:
NASA, Goddard Space Flight Center
Summary:
A NASA satellite has captured the first images of a collision between a comet and a solar hurricane. It is the first time scientists have witnessed such an event on another cosmic body.

This is a still taken from a visualization showing Comet Encke and the coronal mass ejection erupting from the surface of the Sun.
Credit: NASA

A NASA satellite has captured the first images of a collision between a comet and a solar hurricane. It is the first time scientists have witnessed such an event on another cosmic body. One of NASA's pair of Solar Terrestrial Relations Observatory satellites, known as STEREO, recorded the event April 20.

The phenomenon was caused by a coronal mass ejection, a large cloud of magnetized gas cast into space by the sun. The collision resulted in the complete detachment of the plasma tail of Encke's comet. Observations of the comet reveal the brightening of its tail as the coronal mass ejection swept by and the tail's subsequent separation as it was carried away by the front of the ejection.

"We were awestruck when we saw these images," says Angelos Vourlidas, lead author and researcher at the Naval Research Laboratory, Washington. "This is the first time we've witnessed a collision between a coronal mass ejection and a comet and the surprise of seeing the disconnection of the tail was the icing on the cake."

Encke's comet was traveling within the orbit of Mercury when a coronal mass ejection first crunched the tail then ripped it completely away. The comet is only the second repeating, or periodic, comet ever identified. Halley's comet was the first.

Scientists at the Naval Research Laboratory made the observations using the Heliospheric Imager in its Sun Earth Connection Coronal and Heliospheric Investigation telescope suite aboard the STEREO-A spacecraft. Coronal mass ejections are violent eruptions with masses greater than a few billion tons. They travel from 60 to more than 2,000 miles per second.

They have been compared to hurricanes because of the widespread disruption they can cause when directed at Earth. These solar hurricanes cause geomagnetic storms that can present hazards for satellites, radio communications and power systems. However, coronal mass ejections are spread over a large volume of space, mitigating their mass and power to create an impact softer than a baby's breath.

Scientists have been aware of the disconnection of the entire plasma tail of a comet for some time, but the conditions that lead to these events remained a mystery. It was suspected that coronal mass ejections could be responsible for some of the disconnected events, but the interaction between a coronal mass ejection and a comet never had been observed.

Preliminary analysis suggests the disconnection likely is triggered by what is known as magnetic reconnection, in which the oppositely directed magnetic fields around the comet are crunched together by the magnetic fields in the coronal mass ejection. The comet fields suddenly link together, reconnecting, to release a burst of energy that detaches the comet's tail. A similar process takes place in Earth's magnetosphere during geomagnetic storms, powering the aurora borealis and other phenomena.

Comets are icy leftovers from the solar system's formation billions of years ago. They usually reside in the cold, distant regions of the solar system. Occasionally, the gravitational tug from a planet, another comet or a nearby star sends a comet into the inner solar system, where the sun's heat and radiation vaporizes gas and dust from the comet to form its tail. Comets typically have two tails: one of dust and a fainter one of electrically conducting gas called plasma.

"Even though STEREO is primarily designed to study coronal mass ejections, particularly their impact on Earth, we hope this impact will provide many insights to scientists studying comets," said Michael Kaiser, STEREO project scientist at NASA's Goddard Space Flight Center, Greenbelt, Md.

The results will be published in the Oct. 10 issue of the Astrophysical Journal Letters.

View animation at: http://www.nasa.gov/mpg/191092main_encke_visualization.mpg


Story Source:

The above story is based on materials provided by NASA, Goddard Space Flight Center. Note: Materials may be edited for content and length.


Cite This Page:

NASA, Goddard Space Flight Center. "Comet Collides With Solar Hurricane." ScienceDaily. ScienceDaily, 1 October 2007. <www.sciencedaily.com/releases/2007/10/071001145018.htm>.
NASA, Goddard Space Flight Center. (2007, October 1). Comet Collides With Solar Hurricane. ScienceDaily. Retrieved July 27, 2014 from www.sciencedaily.com/releases/2007/10/071001145018.htm
NASA, Goddard Space Flight Center. "Comet Collides With Solar Hurricane." ScienceDaily. www.sciencedaily.com/releases/2007/10/071001145018.htm (accessed July 27, 2014).

Share This




More Space & Time News

Sunday, July 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

This Week @ NASA, July 25, 2014

This Week @ NASA, July 25, 2014

NASA (July 25, 2014) Apollo 11 celebration, Next Giant Leap anticipation, ISS astronauts appear in the House and more... Video provided by NASA
Powered by NewsLook.com
Space to Ground: Coming and Going

Space to Ground: Coming and Going

NASA (July 25, 2014) One station cargo ship leaves, another arrives, aquatic research and commercial spinoffs. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
How A Solar Flare Could Have Wrecked Earth's Electronics

How A Solar Flare Could Have Wrecked Earth's Electronics

Newsy (July 25, 2014) Researchers say if Earth had been a week earlier in its orbit around the sun, it would have taken a direct hit from a 2012 coronal mass ejection. Video provided by Newsy
Powered by NewsLook.com
Raw: ISS Cargo Ship Launches in Kazakhstan

Raw: ISS Cargo Ship Launches in Kazakhstan

AP (July 23, 2014) The Progress 56 cargo ship launched from the Baikonur Cosmodrome in Kazakhstan Wednesday. NASA says it will deliver cargo and crew supplies to the International Space Station. (July 23) 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:
from the past week

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