• The ESA is now tracking 40 000 objects orbiting Earth.
• However, the agency says there are over 1.2 million objects that are smaller than 10cm orbiting our planet, presenting a real danger to other orbital objects.
• The only way to deal with this problem is to start cleaning up our space junk.

Environmental activists often say that humans have left an indelible mark on the planet we occupy and evidence of our existence will remain long after we’re gone. However, there is a growing problem right above our heads that will surely leave a lasting mark for any intelligent species that happens upon our orb.

Of course we’re talking about space debris. While efforts are made to remove satellites and other spacecraft from orbit safely, a lot of junk gets left in space. The European Space Agency says it tracks around 40 000 objects orbiting the Earth. However, the agency reckons that space debris larger than 1cm but smaller than 10cm in size amounts to 1.2 million objects. An object that size moving at orbital velocity could cause some major damage.

One of the major causes of space debris is fragmentation events and in 2024, the ESA found that there were an additional 3 000 objects in orbit because of several large and small fragmentation events. Simply put – when one satellite bashes into another, you have multiple pieces of junk floating around in space. This isn’t just a problem for astronomers and scientists hoping to get a clear view of the universe, it’s a threat to commercial operations as well.

“There is a scientific consensus that even without any additional launches, the number of space debris would keep growing, because fragmentation events add new debris objects faster than debris can naturally re-enter the atmosphere, also known as the Kessler syndrome. This chain reaction can make certain orbits become unsafe and unusable over time as debris continues to collide and fragment again and again, creating a cascading effect,” the ESA notes.

This means that simply pausing launches isn’t good enough as, over a long enough period, Earth’s orbit could be clogged by junk. The ESA states that the time to actively clean up our orbital ecosystem has come.

Cleaning up our act

So how would be clean up space debris?

For one, prevention is better than cure so there are measures in place intended to prevent satellites from becoming space junk at all. This is however not always easy as sometimes a satellite or other vessel can become unresponsive

Projects like ESA’s Active Debris Removal / In-Orbit Servicing aim to do capture satellites like this and deorbits them. This is however, a complex and costly solution.

NASA actually has quite a few different ideas for dealing with space junk of all shapes and sizes. Some of these solutions are similar to the ESA but others involve using laser beams to nudge smaller objects out of orbit. However, these solutions come at a cost to not only launch, but develop.

One of the more interesting solutions NASA has fielded is recycling debris in space. However, while a fantastic idea, the agency reckons it will cost ~$1.4 billion to process all that junk into something useable.

The space junk problem is eventually going to impact everybody that has an interest or operations in space so it’s better to deal with it before it becomes impossible to safely launch new missions or satellite internet is taken offline by a catastrophic collision.

You can read more about this problem in ESA’s 2025 Annual Space Environment Report here.