Sneak Attacks from the Sun

December 8, 2010
This image combines all of STEREO's wavelengths into one three-dimensional photograph (visible with 3D anaglyph glasses). Credit: NASA

(PhysOrg.com) -- Our Sun can be a menace when it sends out powerful solar blasts of radiation towards the Earth. Astronomers keenly watch the Sun to learn more about what powers these solar eruptions, in hopes of being able to predict them. New research shows that one-third of the Sun's blasts are "sneak attacks" that may occur without warning.

"If space weather forecasters rely on some of the traditional danger signs, they'll miss a significant fraction of solar eruptions," said Suli Ma of the Harvard-Smithsonian Center for Astrophysics (CfA).

To reach their conclusion, Ma and her colleagues studied 34 solar eruptions over 8 months using the . STEREO allows us to study the Sun from two different angles simultaneously. It consists of two spacecraft, one ahead of Earth in its orbit and the other trailing behind. The researchers used it to ensure that the events leaving the Sun were definitely on the side facing the Earth.

STEREO is ideal for studying coronal , or CMEs. A CME is a huge eruption from the Sun that blasts a billion tons of highly charged particles into space at speeds greater than a million miles per hour. When those charged particles reach Earth, they interact with our planet's magnetic field, potentially creating a . Such a storm can interfere with , disrupt , or even short out orbiting satellites.

Previous to STEREO, astronomers thought that all Earth-facing CMEs were accompanied by warning signals like flares (smaller explosions accompanied by high-energy radiation), coronal dimmings (darkening of the corona caused by discharge of matter in the CME) or filament eruptions (long ribbons of plasma arching violently out from the ). Therefore, by watching for those signals, we could potentially predict an impending eruption.

This new research found that 11 of the 34 CMEs observed by STEREO were "stealthy," showing none of the usual signals. As a result, any system designed to watch for such warning signs could miss one-third of all solar blasts.

"Meteorologists can give days of warning for a hurricane, but only minutes for a tornado," explained Smithsonian astronomer Leon Golub. "Currently, space weather forecasting is more like tornado warnings. We might know an eruption is imminent, but we can't say exactly when it will happen. And sometimes, they catch us by surprise."

The team plans to continue looking for subtle clues that might allow us to predict an impending "stealth" CME. They caution that their study occurred during a prolonged minimum of solar activity; conditions may change as solar activity increases over the next few years.

"The Sun is entering its stormy season, ramping up toward its next period of maximum activity in 2013 and 2014," said Ma. "The more we learn and understand about it now, the better."

The paper discussing their findings appeared in the Oct. 10, 2010 issue of The Astrophysical Journal.

Explore further: Scientists weather a space storm to find its origin

Related Stories

Scientists weather a space storm to find its origin

August 2, 2005

A team of researchers from the UK and France used SOHO, ACE and the four Cluster spacecraft to study a huge eruption on the Sun, tracing its progress from birth to when it reached Earth.

Solar Eruption Seen in Unprecedented Detail

May 27, 2008

On April 9, the Sun erupted and blasted a bubble of hot, ionized gas into the solar system. The eruption was observed in unprecedented detail by a fleet of spacecraft, revealing new features that are predicted by computer ...

STEREO Reveals the Anatomy of a Solar Storm in 3D

April 28, 2009

(PhysOrg.com) -- Observations from NASA's twin Solar Terrestrial Relations Observatory (STEREO) spacecraft have allowed scientists to reveal for the first time the speed, trajectory, and three-dimensional shape of solar explosions ...

A New View of Coronal Waves

December 11, 2009

(PhysOrg.com) -- The corona is the hot outer region of the sun's atmosphere. The corona is threaded by magnetic fields that loop and twist upwards from the sun's surface, driven by motions of its dense atmosphere.

Understanding coronal mass ejections

October 29, 2010

(PhysOrg.com) -- The corona of the sun is the hot (over a million kelvin), gaseous outer region of its atmosphere. The corona is threaded by intense magnetic fields that extend upwards from the surface in loops that are twisted ...

Recommended for you

Distant planet's interior chemistry may differ from our own

September 1, 2015

As astronomers continue finding new rocky planets around distant stars, high-pressure physicists are considering what the interiors of those planets might be like and how their chemistry could differ from that found on Earth. ...

New Horizons team selects potential Kuiper Belt flyby target

August 29, 2015

NASA has selected the potential next destination for the New Horizons mission to visit after its historic July 14 flyby of the Pluto system. The destination is a small Kuiper Belt object (KBO) known as 2014 MU69 that orbits ...

Interstellar seeds could create oases of life

August 27, 2015

We only have one example of a planet with life: Earth. But within the next generation, it should become possible to detect signs of life on planets orbiting distant stars. If we find alien life, new questions will arise. ...

4 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

genastropsychicallst
1 / 5 (3) Dec 08, 2010
I already goth those eleven scientificalling cyclosigns on my website, from starting with the 'endless'sign until the quadrate'sign' without fictionaling. To be read on my website, Albert.
genastropsychicallst
1 / 5 (3) Dec 08, 2010
Oeps, sorry. I already goth those eleven scientificalling cyclosigns on my website, from starting with the 'endless'sign until the variable'sign' without fictionaling these. To be read on my website, Albert.
Raveon
not rated yet Dec 08, 2010
What's more I don't think we've ever seen the worst it can do yet.

(to the poster above, if your native language is English you really need to stop posting and go back to school or the asylum, whichever you just got released from)
Titto
1 / 5 (2) Dec 14, 2010
What's more I don't think we've ever seen the worst it can do yet.

(to the poster above, if your native language is English you really need to stop posting and go back to school or the asylum, whichever you just got released from)

NOT NICE MY FRIEND....WHO WANTS TO SPEAK ENGLISH!!
I CAN SPEAK 4 LANGUAGES AND YOU? I BET ONLY THE ONE?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.