Why an interstellar comet has scientists excited

An ancient comet that entered our solar system this summer is offering a rare opportunity to learn more about distant planetary systems far beyond the reach of any spacecraft, researchers say.

The comet is special both because it is interstellar — meaning it came from outside our solar system — and also because nickel vapor was detected in the gas surrounding the comet.

This comet, called 3I/ATLAS , is only the third such interstellar object to enter our solar system in recorded history. Observing such a rare occurrence is "extremely valuable for us," because it's the only opportunity to look at this object before it moves out of our solar system, said Darryl Z. Seligman, an assistant professor of physics and astronomy at Michigan State University, who is coordinating international t