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STEREO spacecraft peek at both sides of the sun at once

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STEREO spacecraft A and B on opposite sides of the sunNASA’s STEREO mission has lived up to its name, placing two spacecraft in position to observe both sides of the sun simultaneously. Most solar missions are in mono, so to speak—they rely on a single observatory, from which only one hemisphere of the sun is visible at any given time.

But STEREO comprises twin spacecraft in orbit around the sun, one racing ahead of Earth and one trailing ever farther behind. The mission gathers data for the study of the solar wind and of dramatic solar blasts known as coronal mass ejections. The two STEREO craft launched in 2006 and went their separate ways. On February 6, the separation between the twin orbiters placed them directly opposite each other, with the sun in the middle. For the first time, the entire sun was within STEREO’s grasp. The whole sun as seen by the twin STEREO spacecraft

Of course, that privileged view will not last forever—as STEREO A (ahead) streaks onward from Earth’s perspective and STEREO B (behind) continues to lag, the orbiters are inching away from opposition and will see their fields of view begin to overlap once again. In fact, the craft are slowly closing in on a rendezvous in 2015, when they will cross paths on the far side of the sun.

Orbital diagram of the STEREO A (red) and STEREO B (blue) spacecraft on February 6 and combined STEREO image: NASA

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  1. 1. letxequalx 9:39 pm 02/7/2011

    Is it possible this system would work on Rush Limbaugh?

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  2. 2. watakawinkidink 11:32 pm 02/7/2011

    No, NASA would need much more planning. And sharks with frickin lasers attached to their heads.

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  3. 3. ConcernedCitizen 11:42 pm 02/7/2011

    …and of course now they can also more accurately measure the contribution of the sun-spot activity on the far side of the sun to its effects on Earth’s temperatures and put an end to the global warming myth.

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  4. 4. watakawinkidink 12:42 am 02/8/2011

    You would think. There has been a few hundred scientific, observable facts that offer a factual debate to every mass extinction theory. All of them end up in the same trash bin. Global warming, coronal mass ejections, gamma ray burst, i’m getting dizzy…

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  5. 5. jtdwyer 4:58 am 02/8/2011

    More importantly, we’ll be able to watch that catastrophic coronal mass ejection on our 3-d video systems as it fries the Earth! It’ll be really hot on the internet!

    P.S. I’m sorry, but couldn’t resist!

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  6. 6. psngray 11:44 am 02/9/2011

    What if had just one satellite in orbital opposition to the earth, couldn’t we get continuous stereo data?

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  7. 7. Quinn the Eskimo 6:14 pm 02/9/2011

    Earth fries in sudden, unexpected, Solar Mass Ejection! Film at 11.

    Next. After the break.

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  8. 8. JDahiya 7:02 am 02/28/2011

    Psngray, that may not work, given that it couldn’t possibly transmit signals throught the Sun. So it would certainly require at least one (solar) satellite more, to relay the signals. Given that the Earth is a much bigger target to aim at than another satellite, it would make more sense to send out two spacecraft, and have them both aim at the Earth. The Earth-based observations would then help to calibrate about half the data.

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