Astronomers have revealed new details about the make-up and age of a visiting comet that was born around a distant star. They conclude that the composition of 3I/Atlas is strikingly different from any object found in our solar system.

A trio of recently published studies shed light on the origins of this exotic comet. 3I/Atlas appears to have been born in a cold environment, possibly around 12 billion years ago.

The comet is an interstellar object (ISO), meaning an asteroid or comet that originated outside the solar system. It is the third such object found, after 1I/ʻOumuamua and 2I/Borisov. It was discovered almost exactly one year ago, travelling inbound on a trajectory that has taken it through the inner solar system and out the other side.

These distant origins make ISOs incredibly interesting to astronomers because they are physical pieces of other planetary systems, delivered to us on galactic tides so that they can be studied from the comfort of our own solar system.

As a comet, 3I/Atlas contained frozen ices that “sublimated” – turned directly from a solid to a gas. These escaped (outgassed) from the comet as it was heated by the Sun, creating a visually spectacular coma (bright atmosphere surrounding the object) and tail.

A comet has no internal light source of its own, instead........

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