Dubai: No, it wasn’t a meteor, meteorite, asteroid or a comet.
The Dubai Astronomy Group (DAG) clarified on Tuesday that the flaming fireball seen descending over the night sky of the UAE and Oman on Monday night was space junk.
Residents who saw the celestial spectacle at around 7.30pm on Monday speculated that the fireball flashing through the night sky was a meteor.
Hassan Al Hariri, CEO of Dubai Astronomy Group, told the media on Tuesday that the fireball was the falling debris of the Progress space module, also known as the SL-4 R/B (42972U) — a Russian cargo spacecraft used to re-supply the International Space Station (ISS) regularly.
The 6.4-metre Progress module is an automated, unpiloted resupply vehicle with a cargo capacity of up to 1,700kg. It was first launched to the ISS in 2000 from Kazakhstan.
“We didn’t issue a statement right away because we wanted to be certain about what was happening, if there’s any meteor expected. But it was the Progress module,” Al Hariri said.
Al Hariri said the public can learn how to distinguish burning objects in the sky by doing some research. It is highly unlikely for any space objects to enter the earth’s atmosphere undetected, he said.
“The objective is to identify the object. First, check Nasa’s site if there are any announcements made. Second, check for any meteors or meteorites that are expected. If none of that checked out, then we will look at satellites that are [in orbital decay and are in the process of re-entry to the earth’s atmosphere],” Al Hariri explained.
In this case, the spectacular view was clearly space debris descending, lasting 80 seconds. It showed the spacecraft disintegrating in the upper atmosphere before breaking up into smaller chunks that burned like fireworks.
Al Hariri said the fireball couldn’t have been a meteor as meteors are “flashy, fast [lasting not even one second] and would descend in a more steep angle, not a shallow one like this”.
Satellites over time are subject to orbital “decay”, the process where they lose their orbit due to a drag force and then they start their return to Earth.
When this happens, the space junk re-enters the Earth’s atmosphere but they are designed to fall slowly to ensure that the chunks disintegrate in space, and the leftovers, if any at all, will descend on uninhabitable areas. This makes space junks’ landing non-hazardous.
Al Hariri said this is what happened with the module that re-entered the atmosphere at 4.04pm on Monday at an altitude of 140km over the Arabian Peninsula. It burned up as it was designed to — and if there was any debris, it went over the Empty Quarter and then straight into the Indian Ocean.
“They are designed to move with the earth at a very shallow degree. Maintaining this degree will mean the spacecraft will remain for a time in the upper atmosphere so they can burn properly and disintegrate.”
Al Hariri said there is other space junk expected to fall from time to time. One of which is the Tancredo-1, a small amateur radio satellite that will fall on October 18 and the protective cover of the ISS that will fall on October 19, and another one on October 27.
But these will not be visible in the UAE and if there is any debris, they would be just the size of a mobile phone and negligible.
He, however, urged the public to watch out for real meteor showers that will be visible in the UAE, the Leonids on November 16 and the Geminids on December 13.