It’s been more than a week since reports first emerged of a “glowing ring of metal” falling from the sky and crashing near a remote village in Kenya.
The object weighed 1,100 pounds and was more than 8 feet in diameter when measured after it landed on Dec. 30, according to the Kenya Space Agency. A few days later, the space agency reliably reported that the object was a piece of space debris, saying it was a ring that had separated from a rocket. “Such objects are typically designed to burn up on re-entry into Earth’s atmosphere or to fall over uninhabited areas, such as oceans,” the space agency he told The New York Times.
Since those first reports were published in the Western media, a small group of dedicated space trackers have been using open source data to try to identify exactly which space object fell in Kenya. So far, they have not been able to identify the rocket launch to which the large ring can be attributed.
Now, some space seekers believe that the object may not have come from space at all.
Did it really come from outer space?
Space is increasingly crowded, but large chunks of metal from rockets generally don’t fly around in Earth’s orbit undetected and untracked.
“It has been suggested that the ring is space debris, but the evidence is marginal,” wrote Jonathan McDowell, an astrophysicist who works at the Harvard-Smithsonian Center for Astrophysics. McDowell is highly regarded for his analysis of space objects. “The most likely space-related possibility is the re-entry of the SYLDA adapter from Ariane flight V184, object 33155. However, I am not entirely convinced that the ring is space debris at all,” he wrote.
Another prominent space explorer, Marco Langbroek, believes that it is possible that the ring came from outer space, so he further investigated objects that may have returned to the time when the object was discovered in Kenya. IN blog post written on Wednesday noted that in addition to the metal ring, other fragments that appear consistent with space debris—including material that appears to be carbon foil and insulating foil—have been found several kilometers away from the ring.
Like McDowell, Langbroek concluded that he was the most likely source for the item Ariane V launch which happened back in July 2008, in which a European rocket lifted two satellites into geosynchronous transfer orbit.
The Ariane V rocket was a rather unique rocket in that it was designed with the capacity to launch two medium-sized satellites into geostationary transfer orbit, a destination much more popular in the late 1990s and early 2000s than it is today. To accommodate both satellites, the SYstème de Lancement Double Ariane (SYLDA) shell was placed over the lower satellite to support the mounting of the second satellite on top of it. During the 2008 launch, this SYLDA shell was launched into a geosynchronous transfer orbit inclined at 1.6 degrees, Langbroek said.
Could it have come from a European rocket?
Over the years, this object has been tracked by the US military, which maintains a database of space objects so that active spacecraft can avoid collisions. Due to the lack of monitoring stations near the equator, this object is observed only occasionally. According to Langbroek, its last observation occurred on December 23, when it was in a highly elliptical orbit, reaching perigee just 90 miles (146 km) from Earth. It was a week before the object crashed in Kenya.
Based on his modeling of the possible re-entry of the SYLDA shell, Langbroek believes it is possible that a European object could have landed in Kenya around the time its entry was observed.
However, an anonymous X account using the handle DutchSpace, which despite being anonymous has provided reliable information about Ariane launch rockets in the past, posted a thread this means that this ring could not have been part of the SYLDA shell. With the images and documentation, it seems clear that neither the diameter nor the mass of the SYLDA component matches the ring found in Kenya.
In addition, Arianespace officials he told the newspaper Le Parisien on Thursday that they don’t believe the space debris is connected to the Ariane V rocket. Basically, if your ring doesn’t fit, you have to set it free.
So what was that?
This story originally appeared on Ars Technica.