From Massachusetts to Maryland, sky watchers reported seeing what looked like an alien spacecraft overhead Tuesday night.

No need for alarm — the strange light is likely the result of one of several rocket launches Tuesday night.

It wasn't the rocket itself, but rather excess fuel that was released as the rocket ascended. The "fuel dump" freezes into ice crystals at high altitudes that reflect sunlight back to earth, which is how it is seen from the ground below.

The crystals can take on a spiral shape from the rocket's motion as the fuel is released. They have been spotted a few times with SpaceX launches and are sometimes called a "SpaceX Fuel Spiral."

See the photos below for other recent sightings of fuel spirals:

BERTRAND ILHE This picture taken in the countryside near Dalby-Vi

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