An asteroid big enough to kill a planet has been discovered, astronomers say.

Astrophysicist Dr Brad Tucker said it’s been called 2022 AP7.

“Nothing to worry about, at least for the couple of centuries but yes a new, fairly large asteroid,” he told Laurel, Gary and Mark.

He said it’s been 1.1-2.3 kilometres wide.

Press PLAY below to hear him explain why it’s only just been discovered