Mystery Object in Retrograde Orbit Around Earth is Puzzling Astronomers

Astronomers say it is an "empty trash bag object", with a puzzling, retrograde orbit.


Astronomers have been left puzzled after spotting a mysterious object orbiting Earth some 600 kilometers above the surface.

Experts are calling the object an ’empty trash bag object’ or ETBO, and it has a very unpredictable orbit.

Its been dubbed Earth satellite A10bMLz.
Its been dubbed Earth satellite A10bMLz. Image Credit: Northolt Branch Observatories.

While scientists are still not 100 percent sure what the object is, they say that its most likely leftover debris from a rocket launch. However, what rocket launch the object came from remains another mystery.

ETBOs tend to have very unpredictable orbit patterns.

Most objects of this category stretch several meters across and have a weight of up to one kilogram.

Image Credit: Northolt Branch Observatories.
Image Credit: Northolt Branch Observatories.

This object is mot likely a piece of light material, probably metallic foil, that’s been trapped in orbit after a rocket launch.


The strange ETBO was spotted for the first time by astronomers using the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Haleakala, Hawaii.

After the initial discovery, astronomers from Northolt Branch Observatories in London further analyzed the object and confirmed it was most likely an ETBO.

It’s been dubbed A10bMLz.

They confirmed that the object is very lightweight and several meters across.

Writing about the mystery object, Northolt Branch Observatories explained in a Facebook post: “This suggests that it is what is known as an “empty trash bag object.”

And while the ETBO is most likely trash fro a rocket launch, the object is puzzling astronomers because of its unusual obit.

The object was found to be speeding around the Earth in a retrograde orbit, instead of prograde orbit.


“It is orbiting the Earth in an unusual, retrograde orbit (i=121°), at an average distance of 262,000 km (0.68 lunar distances). The orbit is highly elliptical, with a perigee just 600 km above the Earth’s surface, and an apogee 1.4 times as far out as the Moon. At the time of our observations, A10bMLz was 293,000 km from Earth.”

The object was further analyzed by Project Pluto, which makes planetarium software. They too confirmed that we are looking at an ETBO with a weird orbit.

“At present, we have no idea as to the origin of this object. That’s mostly because its past trajectory is really uncertain,” Project Pluto explained.

Written by Justin Gurkinic

Hey, my name is Justin, and my friends call me Gurk. Why? Becuase of my last name. It sounds like a vegetable. Kind of. I love sleeping and writing. History is my thing.

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