The Mars Hoax: Double Moon on August 2010
“On August 27th … Mars will look as large as the full moon.”
“NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN.”
It’s August once again and so it marks the annual return of the Mars Hoax. The Mars Hoax Season reaches its height in August when emails are flying around the internet claiming Mars will be as big as the full Moon.
Well, the truth is, Mars can never appear as large as a full moon as seen from Earth.
I first received a forwarded email about this during 2003 or 2005 and almost every year, I see a copy of the same message in my inbox, with its contents being recycled and recirculated.
According to some analysis done by researchers, the email began circulating since 2003. The original message somewhat looks like the one below:
“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 (55,763,108 km) 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. Mars will be easy to spot. At the beginning of August it will rise in the east at 10 p.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 12:30 a.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. NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN.”
Well, some of the things mentioned here are true. During 2003, when this hoax started, Mars really did come within 35 million miles of Earth, the closest in recorded history. That really was an unusually close approach and Mars appeared much brighter than usual. The problem is that the original article had a line about when viewed through a telescope at 75x (75 times actual size) Mars would appear the same size as the full Moon. In other words, Mars to the unaided eye, would be 1/75 as large as the full Moon (not nearly as impressive).It will look like a bright red star, a pinprick of light, certainly not as wide as the full Moon.
If Mars did come close enough to rival the Moon, its gravity would alter Earth’s orbit and raise terrible tides.
Mars has a very elliptical orbit so sometimes we have closer approaches than others. The most recent opposition (closest approach) occurred on January 29th, 2010 and Mars was about 99 million kilometers (about 60 million miles) away. However, Mars was not as bright at the 2010 opposition as it can be. Depending on the opposition, Mars can be as close as 35 million miles from Earth just like the case in 2003, when Mars came minutely closer to Earth than it had been in almost 60,000 years. These very close martian oppositions happen every 15 or 17 years. They happen when Earth passes between the sun and Mars within a few weeks of Mars’ perihelion (the point in its orbit when it is closest to the sun).
Still, Mars is fascinating to look at. This month, Mars can be spotted in the western sky after sunset with the other naked eye planets Saturn, Venus and Mercury.
For further reading, the following articles may be useful:
As a piece of advice, when you receive some emails you really feel compelled to forward, read again, google it and confirm its authenticity before forwarding them 😀
(Moon and Mars) Mars NASA/STSci; Moon David Le Conte. Graphic: David Le Conte.