I cannot believe I'm writing yet another column concerning the infamous "Mars Hoax," but indeed, 13 years after it made its first appearance, it sadly has reared its ugly head in cyberspace once again.
In recent weeks, many people have received an email, Facebook message or tweet titled "Mars Spectacular," originating from an anonymous source and passed on to others who couldn't resist forwarding it to their entire address book. The email declares that tonight (Aug. 27), Mars will be closer to Earth than it has been in the past 60,000 years, thereby offering spectacular views of the Red Planet. The commentary even proclaims, with liberal use of exclamation points, that Mars will appear as bright as (or as large as) the full moon!
What is incredible is that intelligent, well-meaning people always fall for this now seemingly annual late-summer gag. At New York's Hayden Planetarium, people call in, asking what part of the sky they should look at to see Mars. People ask if the planetarium will mark this amazing event by setting up telescopes outside so that members of the general public will be able to get a close-up view. [7 Biggest Mysteries of Mars]
One catch: "Aug. 27," as referenced in the message, is actually Aug. 27, 2003. Mars did pass historically close to Earth that night. But even then, Mars appeared just as a very bright star does to the naked eye, not like the full moon.
Currently, Mars is readily visible in the south-southwest sky as soon as it gets dark, flanked to its north by Saturn and to its south by the bright ruddy star Antares. Mars is currently about 80 million miles (129 million kilometers) from Earth.
But Mars will not appear as large as a full moon! In fact, it will look like a very bright, nontwinkling, yellow-orange star; the color comes from its surface, which resembles the color of rust. In terms of apparent size, Mars currently measures only 1/163 as large as the full moon — a far cry from the moon-size apparition many are likely expecting to see tonight.
So the "Mars Spectacular" message is (as it always has been) bogus. "The Mars chain letter gets revived every August," said Alan MacRobert in 2005 as he debunked the same hoax story as a senior editor at Sky & Telescope magazine. "I see it as a good thing, not a bad thing. It's an immunization. If you make a fool of yourself by sending it to your friends and family, you'll be less likely to send them the next email chain letter you get, which may not be so harmless."
In any case, if you receive the message, just delete it.
And let's all hope this will be the last year it will proliferate across the internet (though I sort of doubt it).
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmer's Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.