Featured Research

from universities, journals, and other organizations

IBEX spacecraft images the heliotail, revealing an unexpected structure

Date:
July 10, 2013
Source:
Southwest Research Institute
Summary:
NASA's Interstellar Boundary Explorer spacecraft recently provided the first complete pictures of the solar system's downwind region, revealing a unique and unexpected structure.

The conditions necessary to make the heliosphere, namely the balance of an outward pushing stellar wind and the inward compression of surrounding interstellar gas is so common, that perhaps most stars have analogous structures, called astrospheres. Photographs of three such astrospheres are shown, as taken by various telescopes.
Credit: NASA/ESA/JPL-Caltech/GSFC/SwRI

NASA's Interstellar Boundary Explorer (IBEX) spacecraft recently provided the first complete pictures of the solar system's downwind region, revealing a unique and unexpected structure.

Related Articles


Researchers have long theorized that, like a comet, a "tail" trails the heliosphere, the giant bubble in which our solar system resides, as the heliosphere moves through interstellar space. The first IBEX images released in 2009 showed an unexpected ribbon of surprisingly high energetic neutral atom (ENA) emissions circling the upwind side of the solar system. With the collection of additional ENAs over the first year of observations, a structure dominated by lower energy ENAs emerged, which was preliminarily identified as the heliotail. However, it was quite small and appeared to be offset from the downwind direction, possibly because of interactions from the galaxy's external magnetic field.

As the next two years of IBEX data filled in the observational hole in the downwind direction, researchers found a second tail region to the side of the previously identified one. The IBEX team reoriented the IBEX maps and two similar, low-energy ENA structures became clearly visible straddling the downwind direction of the heliosphere, indicating structures that better resemble "lobes" than a single unified tail.

"We chose the term 'lobes' very carefully," says Dr. Dave McComas, IBEX principal investigator and assistant vice president of the Space Science and Engineering Division at Southwest Research Institute. "It may well be that these are separate structures bent back toward the downwind direction. However, we can't say that for certain with the data we have today."

The team adopted the nautical terms port and starboard to distinguish the lobes, as the heliosphere is the "vessel" that transports our solar system throughout the galaxy.

IBEX data show the heliotail is the region where the Sun's million mile per hour solar wind flows down and ultimately escapes the heliosphere, slowly evaporating because of charge exchange. The slow solar wind heads down the tail in the port and starboard lobes at low- and mid-latitudes and, at least around the Sun's minimum in solar activity, fast solar wind flows down it at high northern and southern latitudes.

"We're seeing a heliotail that's much flatter and broader than expected, with a slight tilt," says McComas. "Imagine sitting on a beach ball. The ball gets flattened by the external forces and its cross section is oval instead of circular. That's the effect the external magnetic field appears to be having on the heliotail."

The IBEX spacecraft uses two novel ENA cameras to image and map the heliosphere's global interaction, providing the first global views and new knowledge about our solar system's interaction with interstellar space.

"We often think we know what we're going to study in science, but the work sometimes takes us in unexpected directions," says McComas. "That was certainly the case with this study, which started by simply trying to better quantify the small structure incorrectly identified as an 'offset heliotail.' The heliotail we found was much bigger and very different from what we expected."

The paper, "The heliotail revealed by IBEX," by D.J. McComas, M.A. Dayeh, H.O. Funsten, G. Livadiotis, and N.A. Schwadron, was published today in the Astrophysical Journal.

IBEX is part of NASA's series of low-cost, rapidly developed Small Explorer space missions. Southwest Research Institute in San Antonio leads the IBEX mission with teams of national and international partners. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the Explorers Program for NASA's Science Mission Directorate in Washington.


Story Source:

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


Journal Reference:

  1. D. J. McComas, M. A. Dayeh, H. O. Funsten, G. Livadiotis, N. A. Schwadron. The Heliotail Revealed by the Interstellar Boundary Explorer. The Astrophysical Journal, 2013; 771 (2): 77 DOI: 10.1088/0004-637X/771/2/77

Cite This Page:

Southwest Research Institute. "IBEX spacecraft images the heliotail, revealing an unexpected structure." ScienceDaily. ScienceDaily, 10 July 2013. <www.sciencedaily.com/releases/2013/07/130710141901.htm>.
Southwest Research Institute. (2013, July 10). IBEX spacecraft images the heliotail, revealing an unexpected structure. ScienceDaily. Retrieved January 28, 2015 from www.sciencedaily.com/releases/2013/07/130710141901.htm
Southwest Research Institute. "IBEX spacecraft images the heliotail, revealing an unexpected structure." ScienceDaily. www.sciencedaily.com/releases/2013/07/130710141901.htm (accessed January 28, 2015).

Share This


More From ScienceDaily



More Space & Time News

Wednesday, January 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Asteroid's Moon Spotted During Earth Flyby

Asteroid's Moon Spotted During Earth Flyby

Rumble (Jan. 27, 2015) Scientists working with NASA&apos;s Deep Space Network antenna at Goldstone, California discovered an unexpected moon while observing asteroid 2004 BL86 during its recent flyby past Earth. Credit to &apos;NASA JPL&apos;. Video provided by Rumble
Powered by NewsLook.com
Water Fleas Prepare for Space Voyage

Water Fleas Prepare for Space Voyage

Reuters - Innovations Video Online (Jan. 26, 2015) Scientists are preparing a group of water fleas for a unique voyage into space. The aquatic crustaceans, known as Daphnia, can be used as a miniature model for biomedical research, and their reproductive and swimming behaviour will be tested for signs of stress while on board the International Space Station. Jim Drury went to meet the team. Video provided by Reuters
Powered by NewsLook.com
Mars Rover Opportunity Celebrates 11-Year Anniversary

Mars Rover Opportunity Celebrates 11-Year Anniversary

Rumble (Jan. 26, 2015) Eleven years ago NASA&apos;s Opportunity rover touched down on Mars for what was only supposed to be a 90-day mission. Since then it has traveled 25.9 miles (41.7 kilometers), further than any other off-Earth surface vehicle has ever driven. Credit to &apos;NASA&apos;. Video provided by Rumble
Powered by NewsLook.com
NASA's On Course To Take Pluto's Best Photo Ever

NASA's On Course To Take Pluto's Best Photo Ever

Newsy (Jan. 25, 2015) NASA&apos;s New Horizons probe is en route to snap a picture of Pluto this summer, but making sure it doesn&apos;t miss its one chance to do so starts now. 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