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August 24, 2005

You've probably received the email, haven't you? The one that breathlessly says that Mars will appear as big as the full Moon in the sky? That says Mars will be closer to the Earth on August 27th than it has in 5000 years, and it may be 2267 until it gets this big again? If you haven't seen it, I have reprinted it at the bottom of this page.

Don't believe everything you read. The email is wrong. Mars won't be closest in August, it won't be as big as the full Moon, and it was actually closer back in 2003. But the best part is that this email is a joke, like a meme. It's a near-exact duplicate of an email sent around the internets back in 2003, August 2003, to be exact, when Mars really did have a close apparition with the Earth. Someone out there in web-land took that old email and started sending it out again. It caught on, and now everyone has seen it.

First, you can read my review of the original email. That pretty much covers all the bases of the email. One thing that's changed is the part about Mars looking as big as the full Moon. It said that back in 2003, but the difference now is that there is a paragraph break in the middle that makes it worse. It actually now says:

... it will attain a magnitude of -2.9 and will appear 25.11 arc seconds wide. At a modest 75-power magnification

Mars will look as large as the full moon to the naked eye. Mars will be easy to spot...

People who skim emails and only read the first lines of each paragraph (I do that too sometimes!) will miss that last line, and think Mars will be that close! But as I point out in the other article, that's simply not possible.

In fact, in 2005, Mars will be closest to Earth in late October, not August. It'll be about 70 million kilometers (45 million miles) away (compared to 56 million km/35 million miles in 2003). While farther away than in 2003, for northern hemisphere observers it'll be placed higher in the sky, and so it'll be easier to see and look better in a telescope, even though it wil look smaller than it did two years ago.

So if you have a local astronomy club, check them out late this fall and take a look. And if you miss, don't worry: Mars will look big and bright again in just two years, not 262. And you can find out more at the website for the magazine Sky and Telescope.

Here is the email in all its glory. Remember: it's almost completely wrong!

The Red Planet is about to be spectacular!

This month and next, Earth is catching up with Mars in an encounter that will culminate in the closest approach between the two planets in recorded history. The next time Mars may come this close is in 2287. Due to the way Jupiter's gravity tugs on Mars and perturbs its orbit, astronomers can only be certain that Mars has not come this close to Earth in the Last 5,000 years, but it may be as long as 60,000 years before it happens again.

The encounter will culminate on August 27th when Mars comes to within 34,649,589 miles of Earth and will be (next to the moon) the brightest object in the night sky. It will attain a magnitude of -2.9 and will appear 25.11 arc seconds wide. At a modest 75-power magnification

Mars will look as large as the full moon to the naked eye.

image of Mars image of Mars
Mars will be easy to spot. At the beginning of August it will rise in the east at 10p.m. and reach its azimuth at about 3 a.m.

By the end of August when the two planets are closest, Mars will rise at nightfall and reach its highest point in the sky at 12:30a.m. That's pretty convenient to see something that no human being has seen in recorded history. So, mark your calendar at the beginning of August to see Mars grow progressively brighter and brighter throughout the month.

Share this with your children and grandchildren.


©2008 Phil Plait. All Rights Reserved.

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