Science & Tech
Planned NASA mission to the 'ignorosphere' could improve space weather forecasts
There is a layer of Earth's atmosphere that scientists know very little about. Dubbed the "ignorosphere," this layer at the edge of space plays a huge role in determining the intensity of space weather events.
A new space mission is in the works that will attempt to shed more light on the processes that take place there, but it won't be ready before the current solar cycle ends.
When bursts of charged particles from the sun that form the solar wind hit Earth, strange things happen in the planet's gaseous coat. Those heavy particles (protons, electrons and heavy ions) collide with atoms in the upper atmosphere, energizing them, Juha Pekka Luntama, the head of space weather at the European Space Agency (ESA), told Space.com.
Most of this energy exchange happens in the thermosphere, the second-highest layer of Earth's atmosphere that extends between altitudes of 60 miles to 360 miles (100 to 600 kilometers). The excess energy warms up the thermosphere and makes it swell. The density of the thin gases that fill this region of space increases. In turn, satellites in low Earth orbit face more drag and sometimes prematurely fall to Earth.
"It's like running against the wind," Anja Stromme, the manager of ESA's Swarm mission, which recently experienced problems maintaining altitude due to bad space weather, told Space.com.
Most of these changes happen in the lowest layer of the thermosphere at altitudes of 60 miles to 120 miles (100 to 200 km), just above the Karman line, a widely recognized boundary between Earth's atmosphere and outer space. Scientists sometimes call this region "the ignorosphere," due to the dearth of data collected there.
"It's too high for balloons but too low for satellites," said Stromme.
Without these measurements, space weather forecasters have little means to improve their predictions of changes that happen in this region in response to solar flares and other sun eruptions. They have no way of providing proper insights to satellite operators whose spacecraft are at risk. In February this year, SpaceX experienced first hand how serious this risk can be when it lost 40 brand-new Starlink satellites that were victimized by bad space weather right after launch.
"When we see an event on the sun, we can give a warning to satellite operators to be cautious and aware," Luntama said. "But it's very difficult to forecast exactly how big the impact is going to be and how much the atmospheric drag for the satellites will increase."
Read here:
https://www.space.com/nasa-esa-space-weather-mission-ignorosphere