Space junk is a term for defunct man-made objects in the Earth orbit, which no longer serve a useful function. Space junk has been amassing since the first artificial satellite, Sputnik 1, escaped Earth’s gravity on October 4, 1957.
In fact, that momentous event started the Space Age as we began to explore the universe further with more than 4,700 launches till now. But, in the unquenchable thrist to conquer the universe, we are leaving enormous trash in universe.
The junk includes parts of rockets and the satellites (once they die). Also space junk includes bits and pieces lost to space including paint chips, nuts and bolts, garbage bags, screwdriver, spatula, etc.
But the number has increased sharply in recent decades due to the 2009 satellite collision and China’s 2007 destruction of the Fengyun-1C weather satellite during an anti-satellite missile test (it created more than 3,000 fragments).
On March 27, 2019, India announced it also successfully completed an anti-satellite missile test, creating a new cloud of at least 400 pieces of debris, which increased the risk of impacts to the International Space Station (ISS) by an estimated 44 percent over a 10-day period(However, the positive side was unlike China’s high-altitude test in 2007, India’s missile targeted a low-altitude satellite, Microsat-R, which means most of this debris is expected to re-enter Earth’s atmosphere over a time).
With the growing amount of space junk, there are fears that satellite collisions could set off a chain reaction (called the Kessler syndrome after American scientist Donald Kessler) in which the space debris would destroy other satellites and as a result the low Earth orbit would become unusable.
Junk left on the Moon
Not only have we left a lot of space junk in Earth’s orbit, there are objects on the lunar surface as well. Some things were abandoned on the Moon by astronaunts, but others were placed there as mementos.
Three Moon buggies from Apollo 15, 16 and 17
54 uncrewed probes that have crashed or landed on the Moon
190,000 kg of material left by humans on the Moon
First spacecraft and probes left on the Moon by different countries:
1959: Luna 2 (USSR)
1969: Ranger 4 (USA)
1993: Hiten (Japan)
2006: SMART-1 (Europe)
2008: Chandrayaan-1 (India)
2009: Chang’e-1 (China)
2019: Beresheet (Israel)
Strange objects left on the Moon
1969: A golden olive branch (Apollo 11)
1969: Art by Andy Warhol (Apollo 12)
1971: Three golf balls (Apollo 14)
1971: A falcon feather (Apollo 15)
1972: A photograph of astronaut Charles Duke’s family (Apollo 16)