Miloch wrote in
:

https://www.bbc.com/news/world-us-canada-51299638

A group tracking the satellites said it predicted a 1 in 20 chance of
a collision, calling it "alarming".

The satellites are not in operation, but it is feared a collision
could create pieces of debris that would damage other objects in
orbit.

The last time a major satellite collision occurred was in 2009.

--- The satellites may pass within 40ft (12m) of each other, some
550 miles (900km) above Pittsburgh at around 18:30 local time.

LeoLabs, a group that tracks space debris, reported that "it is still
unlikely that these objects will collide", but that due to the size of
the satellites, the chance of collision had gone up from prior
calculations.

The objects in question are an Infrared Astronomical Satellite (IRAS)
that was launched in 1983 and another experimental US craft, the
GGSE-4 satellite, launched in 1967.

The IRAS satellite has a 60ft (18m) boom - equipment designed to
deploy antennae or solar sails - trailing it, which increased the
probability of collision as of Tuesday afternoon calculations by
LeoLabs.

Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for
Astrophysics, said that given the size of the satellites - about the
size of a car and a rubbish bin - "a 15-to-30 metre predicted miss
distance is alarming" - a sentiment echoed by LeoLabs.

If they do collide, the debris poses no threat to the city, experts
say, it will burn up in the atmosphere before it can fall to Earth.
But the debris cloud that remains in orbit could threaten other
satellites.

Debris can remain in orbit for decades to centuries.

The last large collision of satellites happened in 2009, when a US
commercial Iridium spacecraft hit a defunct Russian satellite over
Siberia, producing thousands of pieces of debris.

International guidelines state that satellites in low earth orbit must
be removed from orbit 25 years after being decommissioned, but these
satellites were launched prior to the rule changes.

The situation has renewed discussions over the importance of cleaning
up space debris.

"Events like this highlight the need for responsible, timely
de-orbiting of satellites for space sustainability moving forward,"
LeoLabs said.

Currently, there are around 2,000 active satellites orbiting the
earth. There are also more than 23,000 pieces of debris larger than
10cm (4in) in orbit, according to Nasa.

According to data from the Union of Concerned Scientists, the US has
1,007 operating satellites, the most by far of any country. The
majority are commercial.

A 2019 article in the Massachusetts Institute of Technology (MIT)
Technology Review stated by 2025, there could be as many as 1,100 new
satellites launching per year.




India deliberately collided two satellites
awhile back creating even more space debris.


https://en.wikipedia.org/wiki/Mission_Shakti