TRANSCRIPT
It seemed like a scene out of a science fiction movie.
A series of objects flew across the skies of Melbourne on Monday (August 7) night, burning to dust as they made their way to the earth's surface.
The curious image caught the attention of onlookers, who were quick to record the flying objects.
Some expressed their admiration while others seemed a bit more troubled.
"Oh my God! Are you joking? I can't believe we just saw that! Oh my God! That's so pretty! Are you joking? I can't believe we just saw that! Wowey! Where's it going to hit? It's going to go in the water. Nah, see it's going across the sky."
But it turns out that the objects that made the skies of Melbourne turn brighter and a bit more mysterious were of a less foreign origin.
According to the Australian Space Agency, they were nothing more than the remains of the Russian Soyuz-2 rocket re-entering earth's atmosphere.
Dr Alice Gorman is a space archaeologist at Flinders University.
"What the Melburnians saw was the second stage of a Russian Soyuz rocket which had been launched yesterday from the Plesetsk Cosmodrome in Moscow. And the third stage of the rocket went into earth's orbit where it released a navigation satellite. But the second stage, when it still ran out, was let go from the rocket and fell back to earth. So, what everyone saw was the rocket stage burning up in the atmosphere."
The term "space junk" could be used to narrow down the observation of these objects on Monday night in Melbourne.
But, what exactly does that term define?
Associate Professor of astronomy at Monash University Michael Brown explains.
"So space junk is basically left over bits of satellites and rockets that are no longer in use and are no longer operating. So, in this case, this particular rocket had launched a navigation satellite earlier in the day and it launched that successfully and then it was no longer needed and its orbit took it back into the atmosphere and then it re-entered over Melbourne last night just before midnight."
Dr Gorman goes on to explain how the remains from the rocket appeared in the skies of a city in Australia, even though the vessel itself had been launched half way around the world.
"So, the rocket was launched from Russia, the first stage would have fallen off at an earlier point in the launch trajectory, and this one was somewhere in the northern hemisphere I think when it actually was detached from the third stage, and it starts to come back down through the atmosphere, travelling at quite a high speed, so it travels pretty fast, and the path it was tracked on came from down over the north of Australia and then down over the south. So, it had travelled a pretty big distance to get to Melbourne where everyone saw it."
As the two experts explain, the remains of the Russian rocket made their way back into the earth's atmosphere at incredibly high speeds.
Yet despite all that, they never really posed much of a threat to anyone.
Dr Brown says space junk is rarely considered dangerous.
"For the most part, space junk is not dangerous. Most of the rocket burns up in the upper atmosphere and there's relatively little of the rocket that makes it down to earth. There was one of these Soyuz rockets that re-entered over Melbourne just under a decade ago and there were some small bits of tank et cetera, some pressurised tanks that made it down to earth and landed in rural New South Wales, so similar pieces might have made it to earth from this re-entry, but it's very rare for space junk to hit property or injure people."
Regarding any possibility that this debris may not have been of Russian origin, but of some other-worldly beings, those chances appear slim.
Dr Gorman says the truth is far less mysterious than that.
"People might remember that H.G. Wells' 'War Of the Worlds' began with a spacecraft from Mars streaking through the sky a bit like this. But if this was an invasion, burning themselves up as they approach the earth, maybe not the best strategy, I'm just saying."
Dr Gorman goes on to debunk a few more theoretical threats.
"So, there's a lot of conspiracy-theorising around objects in space and there's even a conspiracy theory called 'The Black Night' that says there's been an alien object in Earth's orbit for 13,000 years. There isn't any evidentiary foundation for any of these conspiracy theories. Another popular conspiracy theory is that one nation is deliberately sending space junk over a country to cause damage and, as I've already mentioned, there's really so few recorded instances of any damage or destruction being caused by re-entering space junk. So, while it's kind of fun to speculate, there really is no basis for any of this."
So, while we may come across more instances of night skies lighting up due to orbiting objects re-entering the atmosphere, we can feel safe knowing that none of them are out to get us.
