It's been more than a week since reports first emerged of a “luminous ring of metal” falling from the sky and crashing near a remote village in Kenya.
According to the Kenya Space Agency, the object weighed 1,100 pounds and had a diameter of more than 8 feet when measured after it landed on December 30. A few days later, the space agency confidently reported that the object was a piece of space debris , saying it was a ring that broke away from a rocket. “Such objects are usually designed to burn up as they re-enter the Earth's atmosphere or fall into uninhabited areas, such as oceans,” the space agency said. 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 determine which space object fell in Kenya. So far, they have not been able to identify the rocket launch to which the large ring may be associated.
Now, some space trackers believe that the object may not have come from space.
Is It Really In Space?
Space is getting tighter, but huge chunks of metal from rockets usually don't fly into 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 respected for his analysis of space objects. “The most likely space-related possibility is the reentry of the SYLDA adapter from the Ariane V184 flight, object 33155. However, I am not entirely convinced that the ring is space debris,” he wrote.
Another well-known space tracker, Marco Langbroek, believes that it is possible that the ring came from space, so he further investigated objects that could go back to the time of the discovery of the object in Kenya. In a blog post written on Wednesday he noted that in addition to the metal ring, other fragments that looked consistent with space debris—including material that looked like carbon wrap and isolation foil—were found several kilometers away from the ring.
Like McDowell, Langbroek concluded that the most likely source for the object was an Ariane V launch which took place in July 2008, where a European rocket lifted two satellites into geosynchronous transfer orbit.
The Ariane V rocket is a somewhat unusual rocket in that it was designed with the capacity to launch two medium-sized satellites into geostationary transfer orbit, a destination that was more popular in the late 1990s and early 2000s than it is today. To accommodate both satellites, a SYstème de Lancement Double Ariane (SYLDA) shell was placed on the lower satellite to support the mounting of a second satellite on top of it. During the 2008 launch, this SYLDA shell was released into a 1.6-degree inclined geosynchronous transfer orbit, 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 objects in space so that active spacecraft can avoid collisions. Due to the lack of monitoring stations near the equator, this object is only observed periodically. According to Langbroek, its last observation occurred on December 23, when it was in a highly elliptical orbit, reaching a perigee just 90 miles (146 km) from Earth. It was a week before something went down in Kenya.
Based on his modeling of the possible re-entry of the SYLDA shell, Langbroek believes that the European object may have reached Kenya at the time its entry was observed.
However, an anonymous X account using the handle DutchSpace, which despite anonymity has provided reliable information about Ariane launch vehicles in the past, posted a thread indicating that this ring cannot be part of the SYLDA shell. From the pictures and documentation, it seems clear that the diameter or mass of the SYLDA part does not match the ring found in Kenya.
Additionally, Arianespace officials told the newspaper Le Parisien on Thursday that they do not believe the space debris is related to the Ariane V rocket. Essentially, if the ring doesn't fit, you should excuse yourself.
So what is it?
This story originally appeared on Ars Technica.
