A million miles from Earth, a new satellite with a long history is now keeping an eye on both our own planet and the particles flowing from the sun. The satellite, positioned 92 million miles from the sun, is called DSCOVR, short for Deep Space Climate Observatory.
After NASA released an image of the Earth produced by DSCOVR yesterday, President Obama tweeted the picture. "Just got this new blue marble photo from @NASA," he wrote. "A beautiful reminder that we need to protect the only planet we have."
But the craft is more than just a machine that takes stirring pictures of Earth. The satellite is, in a sense, two-faced: It will examine our planet and the sun's activity, placed as it is between the two bodies.
"The key thing is that it has a unique viewpoint," Gavin Schmidt, the director of NASA's Goddard Institute for Space Studies, told VICE News.
The information that DSCOVR picks up about the Earth's atmosphere from its special viewpoint between our planet and the sun will help complement data that is being gleaned from other angles by satellites orbiting Earth, and that can help scientists with their weather and climate models, said Schmidt, who's not involved in the DSCOVR program.
But aside from gazing at the Earth, the satellite serves another key purpose: It's a sentry in space helping alert scientists at the National Oceanic and Atmospheric Administration (NOAA) to potentially damaging solar weather.
Doug Biesecker, the chief program scientist for DSCOVR at NOAA, compares the satellite to a buoy off the coast of Florida, which might warn meteorologists of an approaching hurricane.
"That's what DSCOVR is for space weather," Biesecker told VICE News. "Space weather is solar activity, things happening on the sun, that have an impact on systems here on Earth."
In this case, the metaphorical hurricane is a kind of solar phenomenon called a coronal mass ejection, which can damage power grids. If NOAA detects that damaging space weather is approaching, it can provide a 15-60 minute warning to companies that operate power grids, or even airlines that fly routes over the North Pole.
"The solar wind blows off of the sun at a million miles an hour," David Hathaway, a scientist at NASA's Ames Research Center, who is not involved in the mission, told VICE News. Usually the Earth's magnetic field shelters the planet from the wind. Sometimes, a coronal mass ejection occurs, which may or may not coincide with a solar flare, Hathaway said, and depending on its orientation, that ejection can pose a threat to systems on around the globe.
"It's sticking its finger out and testing the solar wind," Hathaway said. "[DSCOVR] measures the density of the plasma, the speed of the plasma, and the strength of the magnetic field, and the direction of the magnetic field. It's really like a weather vane in the solar wind, telling you the conditions, moment by moment."
The new satellite, parked a million miles away, is in what NOAA's Biesecker calls a "commissioning phase," and should be fully online in October. Right now, NOAA uses a satellite called ACE for its solar information, which dates to 1998. "It's been great, but it's a very old satellite," Biesecker said, "and given the importance of these data to protecting the power grid, and other systems like GPS, it was very important to get an operational replacement up."
The DSCOVR satellite has a long history. The idea for it reportedly came to Al Gore in a dream in 1998. The purpose of that satellite, which was eventually called Triana, was to take constant pictures of the earth and make them public. But it was grounded during the Bush administration.
The satellite, which had already been built and has been dubbed by some "GoreSat," was stored in a clean room and kept in "pristine" condition, Biesecker said. When NOAA realized they needed to replace ACE, they asked NASA if they could have the Gore-era satellite.
"So we and the Air Force funded NASA to bring it out of storage. We checked it out, [and] saw that it was still in good health," Biesecker said, although it needed a new battery and other fixes. "We didn't want it for the Earth-science side of it, we wanted it for the space weather," he added. That required making changes to the craft.
And so a satellite whose original mission was to image the earth ended up being launched, in February, because it will help NOAA monitor the sun.
The image that NASA released yesterday shows North America beneath swirling clouds.
"I've already been lucky enough to see images of the rest of the globe, and [they] are spectacular — the whole world will be able to participate," Biesecker said. "That was in fact the original idea, the Al Gore idea, we'll call it."
While the solar weather data will come down continuously, he said, the images of Earth will be downloaded once per day, when the United States faces the satellite.
The pictures of the Earth — the blue marble images — will be taken multiple times daily, Biesecker said. "So what will be pretty cool, as you get those, if you stitch them together into a movie," he added, "you'll see the way everything is changing in terms of the clouds, and storms moving across the earth."
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