Featured Research

from universities, journals, and other organizations

Scientists Snap Images Of Solar Wind Sweeping Past Earth

Date:
December 10, 2007
Source:
Naval Research Laboratory
Summary:
Large waves of solar material have been seen sweeping past Earth. The SECCHI team has obtained images of the density enhancements whose prior existence was known only from point measurements by in situ spacecraft.

A sequence of HI2B running difference images, showing the apparent motion of a large wave left to right past the Earth during July 19-20, 2007. The great brightness of the Earth produced several artifacts including the vertical streaks of CCD detector bleeding, the sometimes dark and sometimes bright areas around the Earth, and the reflections located across the optical axis on the opposite side of center. The trapezoidal area is an occulter inserted into th field to block the excessive intensity from the Earth when it moves to the right side of the field. The field of view is about 70 degrees centered 53.4 degrees west of the Sun. Solar north is up and the Sun is about 18.4 degrees beyond the left edge of the field.
Credit: Image courtesy of Naval Research Laboratory

Using the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instruments on board NASA's Solar Terrestrial Relations Observatory (STEREO) spacecraft, a consortium of scientists has seen, for the first time, large waves of solar material sweeping past Earth.

The SECCHI team has obtained images of the density enhancements whose prior existence was known only from point measurements by in situ spacecraft.

During relatively quiet solar conditions throughout the spring and summer of 2007, the SECCHI Heliospheric Imager HI-2 telescope on the STEREO B solar-orbiting spacecraft observed a succession of wavefronts sweeping past Earth. The scientists have compared these white-light images with in situ plasma and magnetic ?eld measurements obtained by near-Earth spacecraft, and found a perfect association between the occurrence of these waves and the arrival of high-density regions that rotate with the Sun. These compression regions are believed to form as high-speed wind from dark areas of the solar corona known as coronal holes run into the low-speed wind in front of it.

Currently, the researchers are tracking HI-2 waves backward toward the Sun to see exactly how they originate. Preliminary results suggest that the waves begin as blobs of material that are shed continuously from coronal streamers.

The STEREO twin spacecraft were launched on October 25, 2006 with the objective of obtaining stereoscopic observations of the Sun from a near-Earth orbit. After some initial maneuvers, which included a gravitational assist from the moon, the two spacecraft achieved their orbits with one spacecraft (A) located slightly closer to the Sun and gradually moving ahead of Earth and the other spacecraft (B) located slightly farther from the Sun and gradually falling behind. The angular distance between the A and B spacecraft increases at a rate of approximately 45 degrees per year and was about 26 degrees in early September 2007.

Each spacecraft is equipped with a suite of Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instruments. In addition to an extreme ultraviolet imager (EUVI), there are two coronagraphs (COR1 and COR2) and two heliospheric imagers (HI-1 and HI-2) pointing 13 degrees and 53 degrees off to the side.

The STEREO/SECCHI data used in this research were produced by an international consortium including NRL, Lockheed Martin Solar and Astrophysics Lab, NASA Goddard Space Flight Center, Rutherford Appleton Laboratory, University of Birmingham, Max-Planck-Institut fur Sonnensystemforschung, Centre Spatiale de Liege, Institut d'Optique Thorique et Applique, and Institut d'Astrophysique Spatiale.

The team's results will be discussed during an invited talk by Dr. Neil Sheeley of the Naval Research Laboratory (NRL) at the fall meeting of the American Geophysical Union in San Francisco, CA, in December. Dr. Sheeley's talk is entitled "Secchi Observations of Mass Flows in the Inner Heliosphere."The scientific paper is scheduled for publication in the March 1, 2008 issue of the Astrophysical Journal.


Story Source:

The above story is based on materials provided by Naval Research Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Naval Research Laboratory. "Scientists Snap Images Of Solar Wind Sweeping Past Earth." ScienceDaily. ScienceDaily, 10 December 2007. <www.sciencedaily.com/releases/2007/12/071207120825.htm>.
Naval Research Laboratory. (2007, December 10). Scientists Snap Images Of Solar Wind Sweeping Past Earth. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2007/12/071207120825.htm
Naval Research Laboratory. "Scientists Snap Images Of Solar Wind Sweeping Past Earth." ScienceDaily. www.sciencedaily.com/releases/2007/12/071207120825.htm (accessed April 18, 2014).

Share This



More Space & Time News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Baby Moon 'Peggy' Spotted In Saturn's Rings

New Baby Moon 'Peggy' Spotted In Saturn's Rings

Newsy (Apr. 15, 2014) A bump in the rings could be a half-mile-wide miniature moon. It was found by accident in Cassini probe images. Video provided by Newsy
Powered by NewsLook.com
Americas Glimpse Total Lunar Eclipse

Americas Glimpse Total Lunar Eclipse

AFP (Apr. 15, 2014) A total lunar eclipse, the first since December 2011, took place early Tuesday morning with the Americas getting the best glimpse. Duration: 1:19 Video provided by AFP
Powered by NewsLook.com
NASA Showcases Lunar Eclipse

NASA Showcases Lunar Eclipse

AP (Apr. 15, 2014) Star gazers in parts of North and South America got a rare treat early Tuesday morning - a total eclipse of the moon. (April 15) Video provided by AP
Powered by NewsLook.com
Spacecrafts Could Use Urine As Fuel Source

Spacecrafts Could Use Urine As Fuel Source

Newsy (Apr. 15, 2014) New research says the urea from urine could be recycled for fuel. Urea is filtered out of wastewater when making drinking water. 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:
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