'Very high risk' defunct Russian satellite and Chinese rocket body will collide

Roughly 34,000 of them are more than 10 centimeters long. Therefore, there is no way to move one of them out of the way to avoid the potential collision.

It is believed that the Parus satellites acted as a relay system in the wider Tsyklon-B navigation constellation, which among other things provided increased accuracy to Russian Navy ballistic missile submarines during the Cold War. If a collision was to occur, it would be shortly before 2pm, over the Weddell Sea off Antarctica.

Californian company LeoLabs has been monitoring the old satellites, saying on Twitter on Thursday that it continued to be a "very high risk" event.

LeoLabs said that the Chinese rocket body was scheduled to pass directly over its Naseby space junk radar soon after the possible collision.

He added, "We have set to schedule a search status examination during this time to ensure that we only see two objects as expected and we hope to ensure that no new debris is discovered".

Watching this very carefully will be NASA and Roscosmos.

It would use the radar to check whether debris had been created.

The risk has drawn comparisons with - but could be worse - than the 2009 collision between an Iridium communications satellite and another defunct Russian Cosmos satellite with a combined mass of 1510 kilograms that collided at a speed of 42,000km/h in 2009.

An artist's impression released on September 1, 2011 by the European Space Agency (ESA) shows the debris field in Low Earth Orbit (LEO) extending 2,000 km above the Earth's surface, which is based on actual data, not items in their actual size or density.

Experts have warned that two large pieces of space garbage are heading towards each other and could collide in the 01:56 GMT round tonight. If enough debris filled Earth's orbit, there would be great danger to active satellites and even rocket launches.

According to LeoLabs, and as of publication at 3pm EDT, the predicted miss distance for Cosmos 2004 and CZ-4C R/B is just 25 meters (+/-18 meters).

Possible collision of satellites on Friday.

On Wednesday, Rocket Lab spokeswoman Morgan Bailey said that given the size, speed and proximity of the objects being monitored by LeoLabs "everybody in the space industry will be watching it closely with concern".