Two satellites were involved in a near miss over Pennsylvania on Wednesday night, passing about 500 miles (800km) above the Earth’s surface.
The two satellites are defunct, but are still travelling at approximately 33,000 mph (53,000 kmph) in opposite orbits in space.
LeoLabs predicted on Wednesday that the satellites, an old NASA telescope known as IRAS and a decommissioned US military satellite called GGSE-4, had a one in 1,000 chance of colliding and it could be other active satellites at risk.
Dr Brad Tucker, from the Research School of Astronomy and Astrophysics at the Australian National University had said before the incident “these two big hunks of space junk” will be “really close”.
But the two inactive satellites “crossed paths without incident” at about 23.39 GMT, 18.39 local time, a spokesman for US Space Command said.
After they passed, LeoLabs tweeted: “Thankfully our latest data following the event shows no evidence of new debris. To be sure, we will perform a further assessment upon the next pass of both objects over Kiwi Space Radar occurring later tonight.
“We are pleased to report that in the first several radar passes of the two objects after the close approach, we see no evidence of new debris. This event has served to highlight the collision risks caused by derelict satellites in LEO.”
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On Twitter, US Space Command “confirmed the 2 inactive satellites (IRSA & GGSE-4) crossed paths without incident. 18th SPCS monitors space debris 24/7/365 & issues conjunction notifications every day to all Nations to support space flight safety”.
The IRAS was launched in 1983 as a joint project between NASA, Britain and the Netherlands but its mission only lasted 10 months.
There are about 4,500 satellites in space, with about 3,000 of those inactive.
The last time a huge collision occurred was 2009 when an inactive Russian communication satellite, Kosmos-2251, crashed with an active US commercial satellite called Iridium 33.
Last month the European Space Agency announced plans to remove debris from orbit as part of its ClearSpace-1 missions, which will launch in 2025.
There are more than 128 million pieces of debris smaller than 1cm in orbit around the Each, according to figures from the ESA’s Space Debris Office, as well as 900,000 pieces of space junk between 1-10cm and 34,000 pieces larger than 10cm.
SOURCE : https://news.sky.com/story/two-defunct-satellites-in-near-miss-over-pennsylvania-11921417