Elon Musk\u2019s Starlink satellites are falling back to Earth, with up to four burning up in the atmosphere each day, according to space trackers.<\/p>\n
Jonathan McDowell, an astronomer at the Harvard\u2013Smithsonian Center for Astrophysics, told EarthSky that he has recorded \u201can average of between one to two Starlink satellites deorbiting each day in 2025.\u201d That number, he said, could climb to around five per day as SpaceX continues to expand its global network.<\/p>\n
Founded in 2002, SpaceX has become a cornerstone of the global space industry, designing reusable rockets and building the Starlink satellite network that is now responsible for much of the deorbiting activity we see today.<\/p>\n
The company is also central to Musk\u2019s personal fortune, with him owning about 42% of SpaceX, a stake worth roughly $140 billion based on private-market valuations<\/p>\n
Videos showing Starlink satellites burning up in the atmosphere have circulated across social media in recent weeks, sparking public concern over whether they pose any danger to people on the ground.<\/p>\n
There are currently about 20,000 objects being tracked in low-Earth orbit, including 12,000 working satellites, 8,500 of which belong to Starlink.<\/p>\n
Most of these satellites have a lifespan of around five years and are designed to completely burn up in the atmosphere before reaching the surface.<\/p>\n
Burning bright, not dangerous<\/p>\n
So while the fiery trails streaking across the sky may seem alarming, scientists say Starlink reentries are not a threat. The concern, however, lies with other objects that are not under controlled reentry.<\/p>\n
\u201cEvery few months there\u2019s a report of a piece of space hardware that\u2019s reentered that ends up on the ground as a significant piece of debris,\u201d Dr. McDowell said.<\/p>\n
\u201cSo several times a year we\u2019re taking these potshots at people on the Earth and fortunately so far missing. So far we\u2019ve been very lucky, but it won\u2019t last.\u201d<\/p>\n
Unlike Starlink\u2019s self-burning design, uncontrolled debris from defunct satellites and rocket stages could survive atmospheric reentry and land on Earth.<\/p>\n
As the number of satellites in orbit grows, particularly from mega-constellations, the risk of collisions and debris fallout is increasing.<\/p>\n
Hidden costs in the sky<\/p>\n
Even though deorbiting Starlink satellites don\u2019t threaten people directly, scientists are examining whether their atmospheric burn-ups could have subtler consequences.<\/p>\n
Pollutants such as aluminum oxide particles released during reentry could influence the chemistry and temperature of the upper atmosphere.<\/p>\n
While this area of research is still developing, early models suggest the long-term effects could be more significant than previously believed.<\/p>\n
\u201cIt\u2019s not clear yet really, even in the age of the mega constellations, [whether] these effects are going to be big enough to be really problematic, but it\u2019s not clear that they won\u2019t,\u201d Dr. McDowell said.<\/p>\n
\u201cThat research is underway right now, and if it comes back that we\u2019re already doing damage to the atmosphere<\/a> in this way, we\u2019re going to have to rethink some of our disposal strategies.\u201d<\/p>\n For now, the spectacle of Starlink<\/a> satellites burning across the sky remains more of a visual phenomenon than a safety hazard.<\/p>\n