The year 2019 marked the beginning of a new solar cycle and fast-forward four years, this cycle has resulted in an increase in the Sun’s disruptive activities. Currently, the sun is halfway into the new solar cycle, and this is the period when the number of sunspots will continue to increase which in turn would amplify the number of solar eruptions.
Surprisingly, scientists have started noticing the ill effects of this phenomenon as the satellites in low-Earth orbit (LEO) are taking the hits.
What is a solar cycle?
Before understanding the effects of a solar cycle, it is important to understand what a solar cycle is in the first place. According to NASA, the Sun has electrically-charged hot gas which moves around and generates a magnetic field and the solar cycle is a result of this movement of the solar gas. Every 11 years or so, the Sun’s magnetic field completely flips, causing its poles- South and North- to change positions.
Whenever a cycle starts or is nearing its end, the number of sunspots is lower and so are incidents of solar flares and coronal mass ejections that send powerful bursts of energy and material into space.
Increased solar activities are causing satellites to lose altitude
Due to the increased solar activities starting early this decade, the number of satellites losing their altitude has significantly increased. Anja Stromme, ESA’s Swarm mission manager, told Space.com that satellites of the Swarm constellation have lost altitude by about two and a half kilometers in the last five or six years.
“But since December last year, they have been virtually diving. The sink rate between December and April has been 20 kilometers per year,” Stromme added. The Swarm constellation consists of three satellites that are operated by the ESA and are used to measure the Earth’s magnetic field.
This surely is bad news for the ones to be launched in the near future along with those already in orbit, as the solar activities increase, they would sink the satellites further into the Earth’s atmosphere. And since the lower part of the atmosphere offers the most drag, these sinking satellites might eventually plunge into Earth causing communication blackouts.
Notably, we are currently facing the 25th solar cycle which is steeply increasing, according to Stromme. “We do not know if this means that it will be a very tough solar cycle. It could slow down, and it could become a very weak solar cycle. But right now, it’s increasing fast”, she told Space.com