As we, humans, intensify efforts to explore outer space and solve millions of mysteries, the issue of space debris has emerged as a major threat to our own planet. Space debris, also known as space junk, refers to the accumulation of human-made objects in Earth's orbit that are no longer in use or have broken apart. This debris poses a significant threat to operational spacecraft, satellites and future space missions. 

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There has been more space debris in orbit than operational satellites ever since the start of the space age on October 4, 1957. Space debris consists of defunct satellites, spent rocket stages, mission-related debris (lens caps, separation bolts, etc.) and fragments from disintegration, erosion and collisions. 

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The European Space Agency (ESA) annually publishes a Space Environment Report to provide a transparent overview of global space activities. The 2025 report, which has unveiled some alarming trends, is based on data collected until the end of 2024. 

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Key issues

1) ESA said that the amount of space debris in orbit continues to rise quickly. About 40,000 objects are now tracked by space surveillance networks, of which about 11,000 are active payloads. 

Space debris objects larger than 1 cm in size are large enough to be capable of causing catastrophic damage. ESA said that the actual number of space junk is estimated to be over 1.2 million, with over 50.000 objects of those larger than 10 cm (including approximately 9,300 active payloads). 

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2) ESA said that its debris modelling tool, MASTER, shows that in the low-Earth orbit range of around 550 km altitude, there is now the same order of magnitude of debris objects posing a threat as there are active satellites. 

3) In 2024, there were several major fragmentation events as well as several smaller ones. This has led to a large increase in objects in one year, with at least over 3,000 tracked objects added.

4) Overall, re-entry numbers caused by an anti-satellite missile test at the end of 2021 peaked in 2022 but it is fading. Meanwhile, the rapidly rising trend is visible in satellites re-entering the atmosphere. "This is a result of improved compliance with space debris mitigation guidelines to remove satellites at the end of their lifetime from important orbits," the report said. 

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Risks and Consequences

From collisions and environmental concerns, there are several risks and consequences of space debris. They can collide with operational spacecraft, causing damage or destruction. The growing amount of space debris increases the risk of accidents and reduces the safety of space missions. They can also contribute to the pollution of Earth's orbit and the degradation of the space environment. 

Several initiatives are underway to address the issue, including debris removal technologies, improved satellite design for end-of-life disposal, and international guidelines for space operations. 

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(With inputs from agencies)