A Glowing Metal Ring Crashed to Earth. No One Knows Where It Came From

It’s been more than a week since reports first surfaced of a “glowing ring of metal” that fell from the sky and crashed near a remote village in Kenya.

According to the Kenya Space Agency, the object weighed 1,100 pounds and was more than 8 feet in diameter when measured after landing on Dec. 30. A few days later, the space agency confidently stated that the object was a piece of space debris. , said it was a ring that separated from a rocket “Such objects are typically designed to re-enter Earth’s atmosphere or fall into uninhabited areas such as oceans,” the space agency said. told the New York Times.

Since these initial reports were published in the Western media, a small band of dedicated space trackers has been using open source data to try to accurately identify which space objects fell in Kenya. So far, they haven’t been able to detect the rocket launch that the big ring could be responsible for.

Now, some space trackers believe that the object did not come from space.

Did it really come from space?

Space is increasingly crowded, but large chunks of metal from rockets are usually undetected and untracked in Earth orbit.

“It has been suggested that the ring is space debris, but the evidence is marginal,” wrote Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics. McDowell is highly regarded for his analysis of space objects. “A space-related possibility is the reentry of the SYLDA adapter from the Ariane V184 flight, object 33155. Still, I’m not entirely convinced that the ring is space debris at all,” he wrote.

Another prominent space tracker, Marco Langbroek, believed that the ring came from outer space, so he further investigated the object he returned when he discovered 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 carbon wrapping and material that looked like detached foil — were found several kilometers from the ring.

Like McDowell, Langbroek concluded that was the most likely source for the object An Ariane V launch This happened in July 2008, when European rockets lifted two satellites into geosynchronous transfer orbits.

The Ariane V rocket was a rather unique rocket designed to launch two medium-sized satellites into geostationary transfer orbit, a destination in the 1990s. Much more popular in the late 1990s and early 2000s than today. To accommodate both satellites, a SYstème de Lancement Double Ariane (SYLDA) shell was placed over the lower satellite so that a second satellite could be mounted on top of it. At launch in 2008, this SYLDA shell was ejected into a 1.6-degree inclined geosynchronous transfer orbit, Langbroek said.

Could it come from a European rocket?

For 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 tracking stations near the equator, this object is observed only periodically. According to Langbroek, its last observation was 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 an object crashed into Kenya.

Based on modeling the possible re-entry of the SYLDA shell, Langbroek believes that the European object could have landed during its entry into Kenya.

However, an anonymous X account using the Dutchspace handle, which has provided reliable information about Ariane launch vehicles in the past despite remaining anonymous, Post a thread This indicates that this ring cannot be part of the SYLDA shell. With the images and documentation, it is clear that neither the diameter nor the mass of the SYLDA material matches the rings found in Kenya.

In addition, Arianespace officials told Le Parisien newspaper On Thursday they did not believe the space debris was connected to the Ariane V rocket. Basically, if the ring doesn’t fit, you must redeem.

So what was it?

This story originally appeared Ars Technica.