Astronomers had every right to be sceptical when a South African colleague announced the discovery of a new "star" on Tuesday.
Turns out, he'd rediscovered Mars.
In a note posted to Astronomer's Telegram, a website for astronomers to post their findings, cosmologist Peter Dunsby reported the sighting of a "very bright optical transient in the region between the Lagoon and Trifid Nebulae".
He spotted it using a telescopes at the University of Cape Town.
"The optical transient is the brightest star in the field. Further observations are strongly encouraged to establish the nature of this very bright optical transient," he wrote.
It didn't take many further observations to figure out what it was. Just 40 minutes later, a correction was posted to the site.
"The object… has been identified as Mars. Our sincere apologies for the earlier report and the inconvenience caused."
The Astronomer's Telegram commemorated the planetary blunder in a tweet, issung Peter Dunsby a certificate "for discovery of Mars".
Prof Dunsby saw the funny side, tweeting he'd learned a good lesson: "Check, Check, Triple Check and then Check some more."
"What else can you do," he said. "Life is short and at least my blunder made a few people smile, so that's good."
Mars has been known of since at least the second millennium BC. It was first spotted using a telescope in the 1600s by Galileo Galilei.