The US Strategic Command UU It confirmed a spectacular fireball witnessed in Saskatchewan and Alberta on Friday night when the body of the Antares rocket caught fire when it re-entered Earth's atmosphere.
Initially, the witnesses were baffled by the bright light streak, which many thought was a crashing plane or a meteor.
Some described it as melting metal or as slow-motion fireworks.
But the US Strategic Command UU confirmed on Sunday that it was space junk that burned out of orbit and fell toward Earth.
"The 18th Space Control Squadron removed an Antares rocket body from the US satellite catalog as a decomposed object after it re-entered the atmosphere on November 24, 2017, over North America (near Saskatchewan) ) approximately 11:48 pm CDT, "said current operations chief Maj. Brian Maguire
Thanks @Dunlap_Obs -the people witnessed the reentry of @OrbitalATK & # 39; s # Antares reinforcement rocket NORAD ID 2017-071B in #Saskatchewan This AM synchronization location matches the prediction of the spatial path. @CBCCanada article: https://t.co/HuubCyjBve @amsmeteors page: https://t.co/rCQBcf031O pic.twitter.com/LPUdMtJGGH  ] –
The rocket makes the mission possible
The Antares rocket was launched on November 12 on a refueling mission to the International Space Station.
It was used to propel the ISS Cygnus CRS OA-8E spacecraft into space and when it did its job, it fell into orbit along with thousands of pieces of space junk left over from other missions.
Because objects can remain in orbit for decades, there are objects that have been circulating around the Earth since the 1960s.
But scientists predicted that Antares would fall back to Earth by the time that did it.
According to The Aerospace Corporation, this was the predicted ground track of reentry of the Antares rocket body from space. (Aerospace.org)
Scott Young, the manager of the planetarium and science gallery at the Manitoba Museum in Winnipeg, said scientists use a model of the atmosphere to predict when friction will be enough to know that the object will fall
& # 39; It is always possible that some pieces may fall to the ground & # 39;
– Scott Young, director of the Manitoba Museum Planetarium
Calculations can also predict where he will reenter, but any uncertainty may change. the location for hundreds of thousands of kilometers. The predictions for the Antares were that it would be closer to Australia.
"There are probably one or two pieces that fall into the atmosphere every day, however, most will occur in the ocean or in a place where nobody will see them and most of them will be smaller than this particular piece" said Young.
"This was a large one and it was over a well-populated area, so it's quite rare."
The Earth's low orbit, located 2,000 kilometers above the surface of the Earth, has the highest concentration of space debris. (NASA)
Burning on Earth
Young said that the orbits will usually take the discarded pieces to any place between plus and minus 52 degrees of latitude.
That means that they can fall on most of the densely populated areas of the world, so the rockets are built with lightweight materials that will disintegrate upon re-entry.
"They do not want big heavy cast iron pumps or things like that falling on people's heads, so they try to design them so that they burn safely," Young said.
"But it is always possible that some pieces may fall to the ground"
The Strategic Command said that the effects of the atmosphere prevent the Space Control Squadron from accurately tracking any reentry after initial contact with the atmosphere.
Young said that safety is a consideration even before objects fall back to Earth.
Manitoba Museum Planetarium astronomer Scott Young says that witnessing a rocket re-entry like the one on the Prairies on Friday could be a once-in-a-lifetime event. (Trevor Brine / CBC)
Tracking space junk
The Space Control Squadron is currently tracking more than 23,000 objects that are in orbit. They can be seen on the Space-Track website, which is available to the public.
Young said it is crucial to know where the objects are because they may collide with astronauts on the International Space Station.  "[The squadron] basically we have to monitor every little piece of spacecraft and discarded hatch cover and things like that," he said.
"Because even if it's a small piece, when it moves at 30,000 or 40,000 km / h, if it hits you, it's going to be a bad day."
When the objects finally fall, the view from Earth can be impressive.
Young said that for most people it is something that is seen once in a lifetime because larger events such as Antares reentry only occur twice a year. He said that the chances of the average person seeing it twice are relatively slim.
"It really spreads all over the world, so if you saw it you should consider yourself lucky because it's hard to see and it's spectacular," Young said.