The world’s first artificial satellite, the Soviet Union’s Sputnik 1, was launched in October 1957. Just three months later, it fell out of orbit. As Sputnik hit the upper atmosphere at incredible speed, the friction would have caused it to heat up and almost entirely burn off. Some small remnants of the satellite would have remained in the upper atmosphere, like smoke and ash after a fire: humankind’s first space debris.
Seven decades on, scientists like us are only just beginning to piece together how this space debris might be damaging the ozone layer, the climate and even human health. We still don’t know how much of this debris the atmosphere can sustain before it causes significant environmental harm.
Today, the number of objects in orbit has surged to over 28,000. More than 11,000 of these are active satellites, with most belonging to commercial “mega-constellations”: groups of satellites that work together to deliver internet access. Examples include Starlink, operated by Elon Musk’s SpaceX, Amazon’s Kuiper or China’s Guowang.
