Spacecraft Stares at the Sun to Stand Guard for the Earth

NY Times ^ | December 13, 2005 | WARREN E. LEARY

[neverdem]

Battered and somewhat broken, a sentinel stands between the Earth and the Sun, continually watching for impending solar storms and other activities. For a decade, the spacecraft - the Solar and Heliospheric Observatory, or SOHO - has not only peeled back many mysteries of the Sun but also revolutionized studies of the space weather that bathes every corner of the solar system.

Scientists and engineers around the world are celebrating SOHO's 10th anniversary and heralding it as one of the most productive spacecraft ever flown. Built by the European Space Agency and operated by NASA's Goddard Space Flight Center in Greenbelt, Md., it stares at the Sun 24 hours every day and sends back a steady stream of data and images documenting its influence on everything in its realm.

"SOHO brought home the point that we are living in the extended atmosphere of an active star," says Bernard Fleck, the solar physicist who is European project scientist for the spacecraft. "Aside from its scientific accomplishments, it really has revolutionized the whole space weather business and provided a practical early warning system for solar disruptions."

SOHO was launched on Dec. 2, 1995, and four months later took up a position about 930,000 miles from Earth at a point where the planet's gravity and that of the Sun hold it in a line between the two. There, the spacecraft's instruments can provide early warning of mass ejections of solar material that can affect astronauts in space, satellites and distant spacecraft, and power and communications systems on Earth.

Before SOHO, Earth had little or no warning before being hit by a shockwave of high-energy, radioactive particles from the Sun. The spacecraft now provides space weather forecasters up to three days' notice of Earth-directed disturbances, scientists say.

SOHO's suite of 12 instruments has also...

[neverdem]

Images by NASA
WATCHING THE HEAT An image of the Sun taken by the Solar and Heliospheric Observatory, top. The craft hovers between the Sun and the Earth in an illustration.

[bkepley]

thassa spicey meata balla

[ElkGroveDan]

Mama always told me not to look into the sights of the sun
Oh, but Mama, that's where the fun is

[cyberdasher]

neat article. . .

If this was an article about SUVs, the Times would almost certainly include a short snippet about how there is a general consensus among environmental scientists about how it is a fact that the emissions from such vehicles negatively impact our climate.

You think the Times would ever realize that the sun generates more change in our climate than humans ever will?

[manwiththehands]

Now we have three days notice before we know

WE'RE ALL GONNA DIE!"

[SlowBoat407]

Battered and somewhat broken, a sentinel stands between the Earth and the Sun, continually watching for impending solar storms and other activities.

Amazingly heroic writing for a Times person. Nice romanticism there.

[chimera]

ESA and NASA did good with this one. Quite an achievement to keep it going all that time (kinda like we did with Pioneer and Voyager). I always wondered where the information came from concerning solar eruptions. I assumed it was ground-based observations, but it was SOHO all along. Good on yer, little topper.

[Cinnamon]

Libs will find a way to blame Sun Flare changes on earth's climate polcies

[backhoe]

The Sun has a Thousand Faces--- Thread 3

[wallcrawlr]

[neverdem]

Thanks for the link.

[neverdem]

You think the Times would ever realize that the sun generates more change in our climate than humans ever will?

Yeh, when they feel that global cooling predicted 3 decades ago.

[united1000]

SOHO is the little satellite that could!

[Eaker]

Before SOHO, Earth had little or no warning before being hit by a shockwave of high-energy, radioactive particles from the Sun.

Either it can predict a flare before it leaves the Sun or we only get roughly 8 minutes warning.

[Salamander]

Heh heh...obscure....I like that.....;)

[Fatuncle]

No. Light's travel time from Sol is 8 + minutes. Particles, having more mass, are ejected at less speed, and can take hours to make the trip.

It is quite possible to see a magnetic shock wave and flare ejecta by the light it emits well before it hits.

[backhoe]

The subject of the Sun is a sentimental favorite of mine-- long ago, during the Cold War, I was the Polish Solar Observer's Society's lone American observer. Did Sunspot counts for compiling the Wolf Number.

[spunkets]

"Either it can predict a flare before it leaves the Sun or we only get roughly 8 minutes warning."

Light takes 8min. The satellite is placed st 1/10th of the distance to the Sun, so the warning for any light is only 0.8min. Light doesn't matter though, it's the dust kicked up from the Sun that does. That takes ~24 hrs, or longer to get here. That moving dust cloud is what the warning is for. What the satellite can see is the dust cloud interacting with Sunlight and itself. Folks on Earth can't see that, because it's covered up by the atmosphere and the Earht's ionized layers.

[Eaker]

1/10th the distance from the Sun would be 9,300,000 miles.

The rest makes sense though.

Thanks,

[MikeD]

I found out not too long ago that SOHO was only supposed to be a 2-year-mission, and space weather monitoring was NOT part of its mission. Now, there's actually talk about sending up a replacement without some of the space weather capability...