Tag Archives: coronal holes

A Hole in the Sun

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Spacecraft Sees Giant ‘Hole’ In the Sun (Video)

SPACE.com

Megan Gannon
Spacecraft Sees Giant 'Hole' In the Sun (Video)
A space telescope aimed at the sun has spotted a gigantic hole in the solar atmosphere — a dark spot that covers nearly a quarter of our closest star, spewing solar material and gas into space.

The so-called coronal hole over the sun’s north pole came into view between July 13 and 18 and was observed by the Solar and Heliospheric Observatory, or SOHO. NASA released a video of the sun hole as seen by the SOHO spacecraft, showing the region as a vast dark spot surrounded by solar activity.

Coronal holes are darker, cooler regions of the sun’s atmosphere, or corona, containing little solar material. In these gaps, magnetic field lines whip out into the solar wind rather than looping back to the sun’s surface. Coronal holes can affect space weather, as they send solar particles streaming off the sun about three times faster than the slower wind unleashed elsewhere from the sun’s atmosphere, according to a description from NASA.

“While it’s unclear what causes coronal holes, they correlate to areas on the sun where magnetic fields soar up and away, failing to loop back down to the surface, as they do elsewhere,” NASA’s Karen Fox at the agency’s Goddard Space Flight Center in Greenbelt, Md., explained in an image description.

These holes are not uncommon, but their frequency changes with the solar activity cycle. The sun is currently reaching its 11-year peak in activity, known as the solar maximum. Around the time of this peak, the sun’s poles switch their magnetism. The number of coronal holes typically decreases leading up to the switch.

After the reversal, new coronal holes appear near the poles. Then as the sun approaches the solar minimum again, the holes creep closer to the equator, growing in both size and number, according to NASA.

The $1.27-billion (1 billion euros) SOHO satellite was launched in 1995 and is flying a joint mission between NASA and the European Space Agency (ESA). It watches solar activity from an orbit about the Lagrange Point 1, a gravitationally stable spot between Earth and the sun that is about 932,000 miles (1.5 million kilometers) from our planet.

from:    http://news.yahoo.com/spacecraft-sees-giant-hole-sun-video-153040642.html

Big Bird on The Sun

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‘Big Bird’ On Sun? NASA Spies Coronal Hole That Looks Like ‘Sesame Street’ Fave (PHOTOS)

Posted: 06/04/2012 8:48 am Updated: 06/04/2012 10:19 am

Big Bird Sun

This photo from NASA’s Solar Dynamics Observatory spacecraft, snapped on June 1, 2012, captures what looks like Big Bird on the surface of the sun. The feature is actually a coronal hole, a dark area of the sun’s upper atmosphere.

By: Mike Wall
Published: 06/01/2012 03:59 PM EDT on SPACE.com

A new photo from a NASA sun-watching spacecraft highlights a huge solar feature that looks a lot like the beloved Big Bird from the children’s television show “Sesame Street.”

The image, snapped today (June 1) by NASA’s Solar Dynamics Observatory (SDO) probe, actually shows a so-called coronal hole — an area where the sun’s corona, or outer atmosphere, is dark. But the resemblance to Big Bird, or one of his feathered kin anyway, is uncanny.

“I can’t get over how much this looks like Big Bird — but it is a coronal hole on the sun,” reads a Twitter post today by Camilla Corona SDO, the spacecraft’s rubber chicken mascot.

big bird sun

The rubber chicken’s Twitter feed is part of NASA’s social media outreach efforts. Officials pasted a picture of the “Sesame Street” character next to the ‘Big Bird’ coronal hole for comparison.

The image of Big Bird on the sun is an example of pareidolia, which is the tendency of the human brain to recognize animals or other prominent shapes in vague or random images. This view of an elephant’s head on Mars is another example.

Coronal holes are associated with “open” magnetic field lines, which extend out into interplanetary space rather than arc back to the solar surface. Coronal holes are often found near the sun’s poles, Camilla added, and the high-speed solar wind — a stream of charged particles flowing from the sun’s upper atmosphere — is known to originate in them.

The super-speedy solar wind from the ‘Big Bird’ coronal hole will reach Earth between June 5 and June 7, Camilla said.

After remaining relatively quiet for several years, the sun has entered an active phase of its 11-year solar cycle, firing off a number of strong flares and coronal mass ejections (CMEs) — huge clouds of solar plasma — in the past several months.

CMEs that hit Earth inject large amounts of energy into the planet’s magnetic field, spawning potentially devastating geomagnetic storms that can disrupt GPS signals, radio communications and power grids for days, researchers say. These storms can also super-charge the northern and southern lights, generating brilliant shows for skywatchers at high latitudes.

Experts think the current cycle, known as Solar Cycle 24, will peak in 2013.

The $850 million SDO spacecraft launched in February 2010. The probe’s five-year mission is the cornerstone of a NASA science program called Living with a Star, which aims to help researchers better understand aspects of the sun-Earth system that affect our lives and society.

http://www.huffingtonpost.com/2012/06/04/big-bird-sun-solar-feature-nasa-sesame-street_n_1567381.html?ref=science