After a two-year hiatus, the infamous Mars Hoax has once again reared its head.
The Mars hoax, which started in 2004, was widely circulated on the Internet under the subject header "Mars Spectacular." According to the email message, which was forwarded over and over and over to countless numbers of people, on the night of Aug. 27, Mars would make an incredibly close approach to the Earth. So close, that in the sky it would loom as large as a full moon!
The message reappeared every year, but apparently lost some steam after seven consecutive summers, and failed to turn up after 2010. Seemingly, the prank had run its course, but now it has reappeared on two new branches of social media: Facebook and Twitter. [Quiz: Mars Myths and Misconceptions]
The message now reads: "WARNING: August 27 at 00:30 Lift up your eyes and look up at the night sky. On this night, the planet Mars will pass just 34.65 million miles from the earth. To the naked eye it looks like two of the moon above the ground! ... Share the news with your friends, because no one living on this earth has ever seen!"
The infamous message now includes an image of a full moon hanging side-by-side in the sky with an impossibly huge Mars. Impossible because even at its absolute closest approach to Earth (34.6 million miles, or 55.6 million kilometers) Mars can get no larger than 25 arc seconds across. That's 1/72 as large as the apparent size of the full moon when viewed with the naked eye.
As of late Tuesday night (Aug. 27), nearly 600,000 people on Facebook have seen the fanciful image. As to where the image came from, it apparently first appeared in 2009 on a Russian site called "Dream Worlds," strongly suggesting that someone from Russia utilized the image to help bring the old Mars hoax message back to life.
The hoax actually began a year after Mars made a historically close approach to the Earth, in the summer of 2003. It was the closest approach that Mars had made to Earth in nearly 60,000 years. And it happened on Aug. 27 of that year. The infamous "Mars Spectacular" message appeared without fanfare in an anonymous email the following summer and was circulated endlessly, mostly by innocent people who found the prospect of seeing an overly large Mars so intriguing that they just simply had to forward it on to all their family members and friends in their address book.
I once told a reporter that if a dollar were generated every time someone forwarded the bogus message, we could probably pay off the national debt!
Interestingly, in 2007, there was a total lunar eclipse scheduled for Aug. 27. At New York's Hayden Planetarium, the number of phone calls that came in that day asking for details on how to see the fictional full moon-sized Mars outnumbered the calls asking about the eclipse (an event that people could actually observe) by a ratio of about 20 to 1!
Fact: Mars will not appear as large as the moon on Aug. 27 (or any other date for that matter).
Fact: Mars is currently unusually far from Earth (almost 200 million miles away, or about 321 million km), as well as appearing unusually dim and small. It currently is in the constellation Gemini and is visible only during the predawn hours, low in the east-northeast sky. It only appears about as bright as a star of the second magnitude; a little brighter than Polaris, the North Star. And through a moderately large telescope it's a disappointment as its disk is tiny, only about 4 arc seconds across.
Fact: Mars is currently approaching Earth, but only very slowly and very gradually. On April 14, 2014, it will come within 57.4 million miles (92.3 million km) of our planet. By then it will appear just a trifle brighter than the brightest star in the sky, Sirius. But it will appear star-like, and certainly will not in anyway remotely resemble a full moon-sized object.
So, if you've seen "the message" on Facebook, or received a Tweet about it, or even if you've received it the "old fashioned way" via email, just remember, it's just a joke!
Editor's note: If you snap a picture of the moon, Mars or any other night sky sight that you'd like to share for a possible story or image gallery, send photos, comments and your name and location to Managing Editor Tariq Malik at firstname.lastname@example.org.
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, N.Y. Follow us @Spacedotcom, Facebook and Google+. Original article on SPACE.com.