There's an e-mail called "Mars Spectacular" making its way around the Internet this summer. The text of the e-mail claims that Mars is heading for a "once in a lifetime" close approach to Earth on Aug. 27 and will appear as large to the naked eye as the full moon.
Well, if you've received this e-mail, don't get too excited. It's a hoax. It seems this same e-mail rears its ugly head every summer about this time, and I get lots of phone calls from folks wanting to know when and where they can get their once-in-a-lifetime view of Mars.
Fact: Mars is about as far away from Earth this summer as it possibly can be. Believe me, if Mars ever came close enough to the Earth to appear as large as the full moon, we would all be in very serious peril, because the Earth's orbit would be altered and enormous tides would ravage the coasts.
Fortunately, planets don't go careening off into space like hubcaps spinning off cars. The orbits of Earth and Mars are very stable and predictable. The closest that the two planets can ever approach one another is about 35 million miles. Even at that distance, Mars never appears as anything more than a bright, red star to the unaided eye.
Mars and Earth do pass one another in their respective orbits about once every 26 months in an event called opposition. The next opposition of Mars will occur Dec. 24, 2007. In the weeks prior to opposition, Earth closes in on Mars and the Red Planet quickly grows in brilliance to become the second brightest object in the nighttime sky. Only Venus shines brighter. But Mars never, ever comes close enough to show a visible disk except through a powerful telescope.
Mars is now approaching its superior conjunction, when it passes behind the sun as viewed from Earth. At a distance of more than 236 million miles, Mars appears so close to the solar glare that it can't be seen from Earth for a number of weeks.
This isn't the first time that a Mars hoax has been perpetrated upon the unsuspecting masses. On Oct. 30, 1938, radio personality Orson Wells scared the wits out of thousands of his radio listeners with a theatrical broadcast of a realistic-sounding news account of an invasion of Earth by Martians that belched poison gas and fired deadly ray guns. At least his broadcast came with a disclaimer warning listeners that it was only a joke.
This summer's Internet hoax is no more real than Wells' fictional Martians. If the "Mars Spectacular" e-mail shows up in your inbox, go ahead and put it where it belongs - the junk mail bin.
Jimmy Westlake teaches astronomy and physics at Colorado Mountain College's Alpine Campus. He is an avid astronomer whose photographs and articles have been published on the Web sites of CNN.com, NASA's "Astronomy Picture of the Day," Spaceweather.com, Space.com, Discover.com, and in Sky & Telescope, Astronomy, Night Sky, Discover, and WeatherWise magazines.