SOLAR SYSTEM

Detailed explanation-1: -Space junk, or orbital debris, currently threatens human space exploration, scientific research missions, and emerging commercial space services. There are approximately 8, 000 metric tons of debris currently in orbit, including at least 900, 000 individual pieces of debris that are potentially lethal to satellites.

Detailed explanation-2: -Broken down satellites, used rocket parts and other pieces of trash-even astronaut gloves-pollute the near-space environment. That can pose big problems for spacecraft and any astronauts in them.

Detailed explanation-3: -How fast are orbital debris traveling? In low Earth orbit (below 1, 250 miles, or 2, 000 km), orbital debris circle the Earth at speeds of between 4 and 5 miles per second (7 to 8 km/s). However, the average impact speed of orbital debris with another space object will be approximately 6 miles per second (10 km/s).

Detailed explanation-4: -Kessler syndrome: A scenario in which the density of objects in low-Earth orbit is high enough that collisions between objects cause a cascade, with each collision generating space debris that increases the likelihood of further collisions. The Soviet Union launched the first satellite, Sputnik 1, into space in 1957.

Detailed explanation-5: -A breakup in space, especially a collision, can involve a lot of energy, and the pieces are flung away at extremely high speeds. Since there is no air to slow the pieces down the fragments would all fly away from one another and rapidly disappear from view.