Part 1 of 2 Parts
The beautiful northern and southern auroral lights are a result of what is called space weather. The solar wind generated by the Sun is guided by the Earth’s magnetic fields to the North Pole and the South poles. This is usually a relatively harmless phenomena unlike the more powerful solar storms that can knock out satellites.
The Starlink company found out just how destructive these solar storms can be in February of 2022. On January 29th, the Sun sent out a class M 1.1. flare and related coronal mass ejection (CME). Materials from the Sun traveled out on the solar wind and arrived at the Earth a few days later. On February 3rd of 2022, Starlink launched a group of forty-nine satellites to an altitude of only one hundred and thirty miles above the surface of the Earth. Unfortunately, they did not last long in their low orbit.
A group of researched from NASA Goddard Space Flight Center and the Catholic University of America examined the specifics of that particular solar storm. Their analysis identified a mass of plasma that struck our planet’s magnetosphere. The event that spawned that mass of plasma was a halo coronal mass ejection from an active region in the northeast quadrant of the Sun.
The solar materials traveled out at around four hundred and twenty-five miles per hour as a shock-driving magnetic cloud. Think of it as a long ropy mass of solar materials writhing its way through space. As the mass traveled, it expanded and hit solar facing satellites. These included STEREO-A which is space-based observatory orbiting the Sun at the same distance as the Earth. As the satellite slowly catches up with the Earth, it allows scientists to see the structure and evolution of solar storms as they blast out from the Sun and move through space. Eventually, the cloud of solar plasma impacted the Earth’s magnetosphere and created a powerful geomagnetic storm.
One of the side effects of space weather that can influence satellites is warming in a region called the “thermosphere”. That warming increases the density of the upper atmosphere over a short period of time and causes it to swell. A denser atmosphere causes “atmospheric drag”. This occurs when the thicker atmosphere slows down anything moving through it. The denser atmosphere also causes things to heat up.
On January 29th of 2022, the atmosphere thickened enough so that it affected the group of newly launched Starlink satellites. They began to experience atmospheric drag which eventually caused them to deorbit and burn up as they fell to Earth. This event was an expensive lesson about the effects of space weather. It provided people on Earth with a great display of what happens when satellites fall back to Earth. It could have been avoided if Starlink had delayed their launch to account for the threat posed by the solar plasma ejection. They had been warned of the threat and chose to launch anyway.
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