There are thousands of space debris orbiting the earth: what risks do they represent?

Last Friday, during the early morning, A racing car flew over the Spanish sky. This turned out to be one of the millions of remains of rockets and satellites that move at high speed in low Earth orbit and whose disposal is one of the great questions still to be resolved for science.

As a result of the event, the Institute of Space Sciences of Spain quickly ruled out that the car was a missile, as initially thought, considering this striking luminous object that moved through Spanish space a piece of space junk, arousing the interest of astronomy fans.

It turns out that this type of phenomenon is more common than you think. In 2023, around this same time, several observers in Sacramento, in the United States, were dismayed by streaks of light that suddenly illuminated the night sky. Shortly afterwards it was learned that they were flaming remains of communications equipment removed from the International Space Station two years earlier.

It could be millions

Low Earth orbit has become a depository for space debris, where most of it is objects generated by human actions. This is how you can recognize pieces of spaceships, small specks of paint from a spaceship, parts of rockets, satellites that no longer work or explosions of objects in orbit that fly through space at high speed.

According to the latest data from the European Space Agency (ESA), Around the Earth there are some 35,150 cataloged debris, weighing 11,500 tons, from 640 ruptures, explosions, collisions or anomalous events that caused its fragmentation.

However, according to sources from ESA itself, “Not all space debris is tracked and catalogued.” YesOur estimates point to the presence of more than 131 million useless space debris objects between 1 millimeter and 10 centimeters orbiting at an average of 36,000 kilometers per hour around the Earth.

This type of space debris moves at high speeds, as they can be close to 29,000 kilometers per hour, almost seven times faster than a bullet.

Risks and lack of regulation

There are many experts who agree that space junk poses a great danger to the safety of people and their property on Earth.

The professor at the University of Malaga (Spain) José Luis Torres warns of these risks: “Any piece larger than one centimeter is potentially lethal in the event of a collision with operational satellites”of which there are currently about 6,000 in orbit.

Researcher Hugh Lewis, a space junk expert at the University of Southampton (United Kingdom), believes that the amount of space junk “has been underestimated” and that the amount of debris in orbit could multiply by 50 between now and 2100 based on planned operations.

Precisely in this context, the lack of express regulation stands out, beyond an international treaty of the United Nations of non-obligatory compliance. “Space debris is an example of what is called market failure, because since there are no property rights, no one manages it,” indicates Torres.

The atmosphere is a useful ally in removing space debris, since below 480 kilometers above the surface most objects disintegrate naturally in the thick lower atmosphere and burn up in less than 10 years.

However, above 100 kilometers, where the atmosphere is thinner, the opposite occurs and debris is lost to space.

Space debris experts agree that “It is not the responsibility of a single country, but of all the countries that navigate in space”and in that its management is both an international challenge to solve and an opportunity to preserve the space environment for future exploration missions.

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