Today, August 27, has come to be known in some circles as Mars Hoax Day, and with the Mars Curiosity rover in action, there’s plenty of room for hoax.

The hoax, however, comes from well before Curiosity’s time. It originated in 2003, when an email got passed around, claiming that Mars would look as big as the full moon to the naked eye on this day. The email continues to surface each year, and some are receiving it once again this year.

According to Space.com, it may have “begun in innocence” back in ’03. They have an article out today explaining the email’s history. In that, it says:

That year, the email message (of unknown origin) correctly stated that Mars and Earth would converge for their closest encounter in around 60,000 years on Aug. 27. The distance between the planets contracted to 34.6 million miles (55.7 million kilometers) on that date, a mere fraction of their average separation of 140 million miles (225 million km) and, indeed, the closest to here Mars has come since 57,617 B.C.

But then, the email offered up this ambiguous sentence: “At a modest 75-power magnification Mars will look as large as the full moon to the naked eye.” Close-up pictures of Mars and the full moon side-by-side accompanied the text.

Notice the combination of “75-power magnification” and “naked eye” in the same sentence. Perhaps if “naked eye” was never mentioned, this never would have become a hoax.

Given the media attention Curiosity has been receiving, I would not be surprised to see more Mars-related tomfoolery making the Internet rounds. It might be a good day to take any Mars information you consume with a grain of salt (or at least some fact verification).

Surprisingly, there have been no tweets about Mars Hoax Day from the Curiosity Rover Twitter account.

Interestingly, while Twitter is generally known for spreading hoaxes, it seems to be doing a good job today of exposing the Mars hoax.

More on the Curiosity Rover here.

Image: Mars Curiosity