Earth’s newest space sentinel, the Deep Space Climate Observatory, is scheduled to launch to provide a 24-hour view of the Earth’s face and 20- to 30-minute warnings of threatening solar geomagnetic storms before they reach Earth.
“These geomagnetic storms can be very dangerous to critical infrastructure on Earth-power grids, aviation communications systems, satellites in orbit,” said Tom Berger of NOAA’s Space Weather Prediction Centre.
The $340 million National Oceanic and Atmospheric Administration spacecraft will observe both the sun and Earth from a stable point in space roughly one million miles (1.6 million kilometres) away from our planet.
Replacing a decades-old space weather satellite, the craft—nicknamed DSCOVR—is also meant to more accurately observe clouds, weather, vegetation, and pollution patterns with around-the-clock observations of the planet’s sunlit face.
Fast-moving blasts of charged particles erupting off the sun, called coronal mass ejections, can trigger geomagnetic storms if they strike Earth. The most dangerous blasts have a magnetic field that points south, opposite Earth’s magnetic orientation, which allows them to penetrate to the planet’s surface.
These monster storms can induce power surges along pipelines and electrical wires, even triggering transformer blowouts like those that knocked out power across the province of Quebec on March 13, 1989. The famed 1859 “Carrington event” solar storm burned out telegraph wires across North America and sparked northern lights above Hawaii and Cuba.
Until a solar blast reaches a satellite, Bogdan says, scientists can’t tell the direction of its magnetic field. That’s why DSCOVR will orbit at a gravitationally stable Lagrangian point closer to the sun. At this Lagrangian point, the Earth, the sun, and centrifugal force combine to hold the satellite steady.
Watching space weather was originally a secondary mission for DSCOVR when it was first suggested in 1998 by then U.S. Vice President Al Gore. Gore proposed having a satellite that would broadcast a continuous video of Earth from space, a view that might raise environmental awareness and measure how much sunlight is re-emitted back into space by the Earth’s surface, a crucial climate question.