The Edge of the Solar System Is a Weird and Erratic Place

By Andrew Moseman | October 1, 2010 2:51 pm

IBEXThe edge of the solar system is not some static line on a map. The boundary between the heliosphere in which we live and the vastness of interstellar space beyond is in flux, stretching and shifting more rapidly than astronomers ever knew, according to David McComas.

McComas and colleagues work with NASA’s Interstellar Boundary Explorer (IBEX), a satellite orbiting the Earth with its eye turned to the edge of the heliosphere—the bubble inflated by the solar wind that encapsulates the solar system and protects us from many of the high-energy cosmic rays zinging across interstellar space. This week in the Journal of Geophysical Research, the team published the results of IBEX’s second map of the region, and found that its makeup has changed markedly over the span of just six months. Says McComas:

“If we’ve learned anything from IBEX so far, it is that the models that we’re using for interaction of the solar wind with the galaxy were just dead wrong.” [National Geographic]

Read More


Space Probe Launched to Study the Surprising Drop in Solar Wind

By Eliza Strickland | October 20, 2008 8:45 am

IBEX launchOn Sunday, a small space probe with a big mission took off from Earth in a flawless launch, setting off on a two-year assignment to map the edge of our solar system. The Interstellar Boundary Explorer soared into space aboard an Orbital Space Sciences Pegasus rocket that fired as planned at 12:48 p.m. CDT, moments after dropping from the belly of a modified airliner that flew across the South Pacific near Kwajalein Atoll [San Antonio Express-News].

The $169 million NASA probe will settle into a long, elliptical orbit around Earth that takes it beyond the interference of our planet’s magnetosphere, and almost as far as the moon. From there the IBEX will record the impacts of particles that are formed at the edge of our solar system’s protected space, a region known as the heliosphere. The solar wind, a stream of charged particles spewing from the sun at 1 million miles per hour, carves out a protective bubble around the solar system. This bubble … shields against most dangerous cosmic radiation that would otherwise interfere with human spaceflight [AP]. At the edge of the heliosphere, the solar wind slows down as it slams into interstellar space; IBEX will observe the particles created in this “termination shock” to chart the solar system’s perimeter.

Read More


NASA Spacecraft Will Soon Map the Solar System's Distant Edge

By Eliza Strickland | October 7, 2008 10:17 am

IBEXOn October 19, NASA will launch the small Interstellar Boundary Explorer (IBEX) into orbit on a mission to map the turbulent edge of our solar system, where the solar wind slams into interstellar space. While it won’t actually travel beyond all the planets to investigate the solar system’s far reaches, the coffee table-sized spacecraft must escape the area where Earth’s magnetic field reigns, which could interfere with its measurements. The $169 million observatory is due to climb 200,000 miles (322,000 kilometers) above Earth and settle into orbit there for a mission of at least two years. For comparison, the moon orbits about 240,000 miles (385,000 km) from Earth [SPACE.com].

The edge of the solar system is currently being explored directly by the Voyager 1 and Voyager 2 spacecrafts; both Voyagers launched 31 years ago and recently passed the point where the solar wind is slowed by interactions with the interstellar plasma, a point known as the termination shock. These crafts “are mak­ing fas­ci­nat­ing ob­serva­t­ions of the lo­cal con­di­tions at two points be­yond the ter­mina­t­ion shock that show to­tally un­ex­pected re­sults and chal­lenge many of our no­tions,” said [IBEX researcher David] Mc­Co­mas [World Science].

Read More


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles covering the day's most compelling topics.

See More

Collapse bottom bar