IBEX Shows a Slower Sun — And No Bow Shock

**Carol** Sun May 13, 2012 1:09 pm

Carol: Admin; Posts : 31775
Join date : 2010-04-07
Location : Hawaii

Post n°1

IBEX Shows a Slower Sun — And No Bow Shock

Carol Sun May 13, 2012 1:09 pm

IBEX Shows a Slower Sun — And No Bow Shock
http://www.skyandtelescope.com/community/skyblog/newsblog/IBEX-Shows-a-Slower-Sun-150955205.html

The heliosphere is a magnetic bubble that protects the solar system from interstellar space as the Sun plows its way through the galaxy. For decades, scientists believed that the bubble was moving quickly enough to form a bow shock, but that view has been revised in light of new data from the Interstellar Boundary Explorer (IBEX). NASA's Interstellar Boundary Explorer has discovered that the Sun has no bow shock, overturning decades of scientific research. the Sun is still moving (albeit slowly) through the Local Interstellar Cloud, a fluff of higher density gas roughly 30 light-years across. Combined with a relatively strong interstellar magnetic field, the Sun's slower advance is no longer enough to push interstellar gas into a bow shock. At best, it makes a "bow wave," a region of slightly increased density — more like a fast-moving boat than a fighter jet. Since its launch in 2008, the Interstellar Boundary Explorer (IBEX) has measured energetic neutral atoms (ENAs) from its orbit around Earth. These high-speed neutral atoms are created when charged particles in the solar wind interact with atoms coming from beyond the solar system. ENAs provide a unique way of imaging the shape of the magnetic bubble that surrounds the solar system. Neutral atoms can freely cross magnetic field lines, penetrating the Sun's magnetic bubble from interstellar space. Once these ENAs reach Earth, IBEX records them and the directions they came from.

_________________
What is life?
It is the flash of a firefly in the night, the breath of a buffalo in the wintertime. It is the little shadow which runs across the grass and loses itself in the sunset.
With deepest respect ~ Aloha & Mahalo, Carol

**Carol** Sun May 13, 2012 1:13 pm

Carol

Carol: Admin; Posts : 31775
Join date : 2010-04-07
Location : Hawaii

Post n°2

Re: IBEX Shows a Slower Sun — And No Bow Shock

Carol Sun May 13, 2012 1:13 pm

IBEX Shows a Slower Sun — And No Bow Shock May20_Eclipse_series_big

Partial — and Annular — Eclipse of the Sun
to Sweep North America Sunday, May 20th
http://www.skyandtelescope.com/about/pressreleases/Partial-151-and-Annular-151-Eclipse-of-the-Sun-to-Sweep-North-America-Sunday-May-20th-150977245.html

As the solar eclipse on May 20th progresses, its partial and annular phases will look very similar to this eclipse on May 10, 1994. Photo by Fred Espenak / SkyandTelescope.com. Permission is granted for one-time, nonexclusive use in print and broadcast media, as long as the credit above is given. Web publication must include a link to SkyandTelescope.com. - Fred Espenak / SkyandTelescope.com

If you happen to be in a swath of land running from Northern California to Texas, you'll also get a very special kind of partial eclipse: an annular eclipse, in which the rim of the Sun becomes a brilliant ring completely encircling the black silhouette of the Moon. The Sun will be moving down the afternoon sky when a dark dent begins to intrude into one edge. The dent will deepen, eventually turning the Sun into a fat crescent — or, for western half of the continent, a thin crescent. The dent is the silhouette of the new Moon traveling along its monthly orbit around the Earth.

Most Westerners can see the entire eclipse from beginning to end before sunset. Farther east, sunset puts an end to the show while the eclipse is still in progress — affording weird and spectacular sunset scenes just above the west-northwest horizon.

IBEX Shows a Slower Sun — And No Bow Shock May20_Eclipse_map_380px

_________________
What is life?
It is the flash of a firefly in the night, the breath of a buffalo in the wintertime. It is the little shadow which runs across the grass and loses itself in the sunset.
With deepest respect ~ Aloha & Mahalo, Carol