Saturday, May 23, 2009

Mars Hoax


A friend sent me a powerpoint in an email that said that on August 27  "Mars would look as large as the full moon to the naked eye"
Ok that seems exciting but not too likely so lets inhale deeply and remember and think...

In 2003 Mars did make a very close approach to Earth, well if you consider 35,000,000 miles close.  The red planet was 34,647,420 miles (55,757,930 km) from Earth in the summer of 2003. (NASA) Mars's orbit  gets close to Earth's orbit every two years or so and even closer to Earth every 15 or 17 years.   In 2003 the two planets were a lot closer than usual so astronomers used that as an excuse for a bunch of huge star parties and a lot of shameless self promotion.  Hey why not!

Like many other things, a little cutting and pasting and anyone with an email account can tell all of their friends about "the dramatic close approach that hasn't happened for 60,000 years and won't be seen again in our lifetimes"  between these two planets.

Eventually the year gets cut off  and now this email resurfaces every summer.  Of course it isn't correct anymore.  Want to know more ? (for my students the correct answer is "yes".  The rest of you are on your own.)

Here is an article posted by NASA in 2003 describing the original event and another still online in the BBC archive.
I HIGHLY recommend this animation by Randy Russell showing Mars and Earth orbits. 
Play it backwards for about a minute to see the close approach (50 million  Km is about 30 million miles) You can play it forward and see when the next close approach will be.  (Try for 2017 or 2020.)

Here is a bloggers view of the current incarnation of this message and a Google search of "Mars approach" gets many responses like this yahoo answer.
The Adler Planetarium in Chicago posted a PDF titled Mars Hoax because they get so many inquiries every summer.  A blog post from 2007 makes us realize that this email misinformation is a recurring phenomenon. 
So that's the story on Mars but don't despair  the moons of Jupiter will be a glorious sight this summer.  Tonight, May 23, 2009 Jupiter will rise about 2 AM but by August 1 Jupiter will rise a little east of South abut 8 PM and continue across the southerrn sky for most of the night.  You can easily see Jupiter's disc and four of its moons with a pair of good binoculars or a small telescope.

Sky and Telescopes posted a  Javascript utility identifying the moons that Galileo saw 400 years ago.  Writing about his observations got him in some trouble but that's another story...
be good,
Mr. Hazen