A recurring rumor claims that an upcoming close encounter with Mars will be a once in a lifetime event, and that the Red Planet will appear as large as the moon.
It’s not true.
Close encounters with Mars occur every couple of years, although a true once in a lifetime event already happened back in 2003. Other recent and upcoming encounters will look similar to the 2003 event to casual observers.
Let’s take a look at one example of the rumor from a couple of years ago:
“Check it out, guess no one will get much sleep in August.
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 Ea rth 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.
Share this with your children and grandchildren.
NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN”
As spectacular as the prospect of a “close encounter” with Mars seems, the claim above is a hoax which circulates every summer. There have been other occasions when Mars was close to Earth – in October 2005 and December 2007 – and those looked about the same to casual observers as the 2003 event, known as perihelic opposition.
NASA wrote of the 2003 approach:
“Earth and Mars are rapidly converging. On August 27, 2003 — the date of closest approach — the two worlds will be 56 million km apart. That’s a long way by Earth standards, but only a short distance on the scale of the solar system. NASA, the European Space Agency and Japan are all sending spacecraft to Mars this year. It’s a good time to go.”
NASA also pointed out that the 2003 event was “scarcely different” than other perihelic oppositions. The next perihelic opposition will occur on July 27, 2018, although Mars won’t be quite as close as it was in 2003.
The graphic below circulated heavily in August 2014. It echoed the sentiment stated in previous incarnations of the rumor. It reads:
Watch the skies
On August 27, 2014 you will see two moons in the sky, but only one will be the moon. The other will be Mars. This will not happen again until the year 2287. No one alive today has ever witnessed this happening.
As expected, a summertime resurgence of the false rumor has begun in earnest in mid-2015, this time citing the day as August 27, 2015. We spotted the graphic below on July 4, 2015, which states, “Mars will look as large as the full moon to the naked eye.”
By August 10, 2015 the hoax was back in full swing, with heavy sharing on social media, as seen in the following tweet.
On August 27, 2015 at 12:30am Mars will be visible. The next time this will happen will be in 2287…. I can’t wait ? pic.twitter.com/JNdIlAq9eg
— Girl Code (@reIatabIe) August 10, 2015
There are close encounters with Mars every few years, and particularly close encounters occur about every 15 to 17 years. There was a “once in a lifetime” approach which occurred in 2003, but another similar close encounter is due in 2018. The next time Mars will be closer than it was in 2003 will be the year 2287, but it will never appear as large as the moon, as internet memes suggest.
Updated August 10, 2015
Originally published August 2013