A glowing ring of metal fell to Earth, and no one has any idea what it is

Like McDowell, Langbroek concluded that the most likely source for the object was an Ariane V launch that took place back in July 2008, in which the European rocket lofted 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, a SYstème de Lancement Double Ariane, or SYLDA, shell was placed over the lower satellite to support the mounting of a second satellite on top of it. During the launch in 2008, this SYLDA shell was ejected 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 space objects so that active spacecraft can avoid collisions. Due to a lack of tracking stations near the equator, this object is only periodically observed. According to Langbroek, its last observation took place on December 23, when it was in a highly elliptical orbit, reaching a perigee of just 90 miles (146 km) from the Earth. This was a week before an object crashed into Kenya.

Based on his modeling of the possible reentry of the SYLDA shell, Langbroek believes it’s possible that the European object could have landed in Kenya around the time its entry was observed.

However, an anonymous Twitter account using the handle DutchSpace, which despite the anonymity has provided reliable information about Ariane launch vehicles in the past, posted a thread that indicates this ring could not have been part of the SYLDA shell. With images and documentation, it seems clear that neither the diameter nor mass of the SYLDA component matches the ring found in Kenya.

Additionally, Arianespace officials told Le Parisien newspaper on Thursday that they do not believe the space debris was associated with the Ariane V rocket. Essentially, if the ring does not fit, you must acquit.

So what was it?