STEREO Satellites Spot Solar Flare Tsunami

westtxfun writes "The STEREO satellites recently confirmed the existence of solar mega-tsunamis when they captured height data after a sunspot recently erupted. The scale of this tsunami literally dwarfs the Earth's diameter — it was 62,000 miles high and raced across the surface at 560,000 mph! STEREO A and B orbit 90 degrees apart and luckily, one was overhead while the other saw the eruption on the limb. This gave NASA scientists enough data to confirm the tsunami wasn't a shadow, solving a modern solar mystery. The images are simply stunning, to boot."

Re:A way to solve tsunamis problems on Earth ?

[mcgrew]

Reading TFA is uncharacteristic for most slashdotters, but this one is definitely worthwhile.

Solar tsunamis pose no direct threat to Earth. Nevertheless, they are important to study. "We can use them to diagnose conditions on the sun," notes Gurman. "By watching how the waves propagate and bounce off things, we can gather information about the sun's lower atmosphere available in no other way."

"Tsunami waves can also improve our forecasting of space weather," adds Vourlidas, "Like a bull-eye, they 'mark the spot' where an eruption takes place. Pinpointing the blast site can help us anticipate when a CME or radiation storm will reach Earth."

And they're pretty entertaining, too. "The movies," he says, "are out of this world."

Pun aside, the movies ARE great. RTFA please, everyone! You'll be glad you did.

Ahead, not OVERhead...

[Anonymous Coward]

Just correcting the summary, one spacecraft is *ahead* of the other (and of Earth) -- not "overhead". Also, they don't orbit 90-deg apart. They were ~90-deg apart for the even in question but are currently 127-deg apart. This value will increase as they continue in their orbits around the Sun. (By Feb 6, 2011 they will be 180-degrees apart, and will both be "behind" the Sun in ~mid-2015.)

Re:It is probably 62 miles

[Remus Shepherd]

Did you see the animation? That wave looks to be easily 1/14th of the solar diameter, especially near the origin.

What I learned from this article is that sunspots explode. Never knew that; I thought they faded away...

Re:Surf's up

[jbezorg]

Someone with mod points and an agenda to "clean up slashdot"? Half-life and Portal references were modded "offtopic" on the recent LHC article. Or maybe someone is just modding random comments following the order of the mod selection dropdown. "offtopic" for the first comment, "flamebait" the second, "troll" the third...

120, not 90

[necro81]

A correction from the summary: the two spacecraft are nearly 128 degrees apart, not 90. They were launched into slightly different heliocentric orbits [wikipedia.org] that cause the angle between them to increase by about 21 degrees per year. They've already passed through the L4 and L5 Lagrangian points [wikipedia.org] of the Sun-Earth system. In Feb 2011, they'll be on opposite sides of the Sun, then start to converge once again.

Re:They really thought it might be a shadow?

[gyrogeerloose]

It seems counter-intuitive but the sun's corona is brighter than it's actual surface. It's possible that some cooler ejecta from a solar flare could cast a shadow.

Re:Large CME?

[JRManuel]

It depends. If the CME is headed toward the Earth, it could. Otherwise, no. CMEs are like shotgun blasts: a lot of scatter, but you still have to aim the gun in the right direction.

Re:Recent? Try February.

[oneiros27]

Actually, I confirmed it with one of the scientists (Joe Gurman) cited in the article -- there was an article from March that was inaccurate, and this was a correction to that previous article.

But, instead of marking it as a correction, it was posted as a new article. (I can't find the older article, so I don't know if it was removed)

They also linked straight to the movie, rather than to the explanation of what is being seen in the movie, or cite the original posting of the article, which had different images:

http://stereo.gsfc.nasa.gov/news/SolarTsunami.shtml [nasa.gov]
http://www.nasa.gov/mission_pages/stereo/news/solar_tsunami.html [nasa.gov]

Joe also said that this was in fact "tsunami-like" in that it was the result of an initially downward wave that reflected back up, as opposed to other CMEs.

(and I probably should've added a disclaimer earlier -- I work for the STEREO Science Center)

Hey Poindexter!

[paiute]

It's tsunamis, not tsunami's.