Mars “as big as the Moon”!
In the past few years, the Internet has been flooded with promises of a spectacular and unique view of Mars in late August. You probably received a message or slide show recently in your e-mails – you may even have forwarded it to all your contacts.
Unfortunately, it’s all just a hoax. First of all, the claim that Mars will appear to be “almost as big as the full Moon seen with the naked eye” is a gross exaggeration – nothing more than a very awkward turn of phrase. Unless you look at it through a telescope, the Red Planet will always be too small and distant to appear as anything more than a bright spot in the sky. The apparent size of Mars mentioned in the message (25.11 arc seconds wide) is actually 70 times smaller than the full Moon!
This exaggeration appears to be the result of an unfortunate line break. An e-mail originally published in English in 2003 read “At a modest 75-power magnification Mars will look as large as the full moon to the naked eye.” But when the text was copied elsewhere, the first part of the sentence was left on another line, and eventually overlooked. As a result, the meaning of the sentence changed completely. When it was translated into French, this part of the sentence was often dropped altogether!
The rest of the text is based on the circumstances surrounding the record close encounter of the Earth and Mars on August 27, 2003. At that time Mars was closer to the Earth than at any time in the previous 60,000 years, and will not come as close to our planet again before 2287. That’s what made this opposition “historic”: Mars would be closer, larger and brighter (but not as much as the Moon!) than at any time in human memory. In short, the message has been old news since 2003.
This hoax circulated in July-August 2005, and again in 2006, and in a slightly different form in 2007. Since there is no mention of the year in the message, it is all too likely to reappear in your inbox again year after year …
For more details on the circumstances surrounding the record opposition of Mars and Earth in August 2003, download the summer 2003 issue of our Pocket Planetarium newsletter.