Earthsky Tonight
Will Mars appear as large as a full moon in August 2009?
08-25-2009 - Astronomy Essentials
It’s happening again. People are clamoring for information about an amazing spectacle involving the red planet Mars. An email is circulating suggesting that – on August 27, 2009 – Mars will appear as large as a full moon in Earth’s sky. The version I saw actually included a powerpoint presentation, suggesting that Mars and Earth’s moon will appear as a “double moon” in late August 2009.
It sounds amazing! Can it possibly be true?
No. It can’t. The email is a hoax. It has circulated every summer since 2003. Mars can never appear as large as a full moon as seen from Earth, and Mars will not even be at its brightest in August of 2009.
In fact, in August of 2009 Mars is a relatively inconspicuous dot of reddish light in our eastern predawn sky. It did appear near the moon this month – a waning crescent moon visible before dawn – on the morning of August 16. That waning moon might have made Mars slightly more conspicuous than it would have otherwise been. Now the moon has moved on in its orbit around Earth, leaving Mars behind, and unless you know exactly what you are looking for, you probably will have trouble finding Mars for the rest of this month.
Ah, Mars. World of dreams and visions. Mars is the world orbiting one step outward from Earth’s orbit. This world is slightly smaller than Earth – but slightly larger than Earth’s moon. Mars is also much much farther away than Earth’s moon. It’s hard to comprehend what little specks the planets and moons are in contrast to the vastness of space, but let me put it this way. Earth’s moon is about a light-second away. Traveling at 186,000 miles per second, light bouncing from the moon’s surface takes about a second to reach us here on Earth. Meanwhile, light from Mars takes much much longer to reach Earth – from several minutes to about 20 minutes – with the difference being the result of Earth’s and Mars’ motions around the sun. In other words, when Mars is on the same side of the sun as Earth, its distance from us is less than when it’s on the far side of the sun from us.
The moon is much closer than Mars, and that’s why we see the moon as a bright disk in our sky. Meanwhile – to the eye – Mars never appears as anything but a ’star.’
So how did this rumor of Mars-as-big-and-bright-as-the-moon get started? It started with an actual event, in 2003. On August 27 of that year, Earth and Mars came very slightly closer than they’d been in nearly 60,000 years. Our two worlds, center-to-center, were about 35 million miles apart – just over three light-minutes apart. The last people to come so close to Mars were Neanderthals. Astronomy writers like me had a field day that year, talking about Mars at its closest. Was it a spectacular sight? Yes! It looked like a dot of flame in the night sky. But was Mars as big and bright as the moon, even at its closest in 2003? Never.
What is happening on August 27 of 2009? Nothing, really. By coincidence, there will be a reddish star near the moon on August 27, the star Antares in the constellation Scorpius. The name Antares or Ant-ares means ‘rival of Mars.’ Antares is sometimes called Mars’ rival because both Antares and Mars appear reddish, and because the planet Mars sometimes appears brighter than this star.
This August, though, Antares appears brighter than Mars does in Earth’s sky. Will some people look outside on August 27 – see Antares near the moon – and think this reddish star is Mars?
Probably.
And so the legend continues …
Hi Deborah,
Great new website. Thank you for contacting me on and informing me of this new sight. Come a long way from the original. Thank you for also clarifying the question posed about how large Mars will appear. I think you may have already answered this question a couple of times in the past since 2005.
I too have been sent numerous emails on this very same subject involving the size of Mars. So tell me how can someone email you with some information relative to magnetic field lines, fractals, and light matter? Thanks, William D. Bedor Atlanta, Georgia
Last night, August 24, we saw a very bright, reddish, large appearing “star” in what we think might be the south west (or maybe east) sky. Would this be Mars? Or what?
Hi Amy.
That bright, ruddy light was probably Antares, the brightest star in the constellation Scorpius. Look for the moon right next to Antares on the evening of August 27. In late August and early September, Mars rises in the east after midnight. At morning dawn, look for Mars roughly halfway between the eastern horizon and straight overhead. The moon will pair up with Mars at and before dawn on September 13, 2009.
Hello,
…
my nightcolleague (I’m an RN) told me about “the double moon”, but that was all she could tell me.
if something is REALLY happening worldwide, I always have my news sources, but I hadn’t heard about this so called double moon, not even in the circle of my cruising / sailing friends …
so: I googled it for my colleague and found your site …
thanks for the information …
I’ll keep looking to the sky anyway, be it Aug. 27 or not
Greetz,
Anya
Anya, yes keep looking! Lots to see in the night sky …
what time it is
I’m really disappointed!!!
I was waiting all month for this!!! WTF! No fair
My sons teacher had me up looking for Mars! Im glad I found this article or I would have been up all night.
That SUCK’S I was supposed to have sex on a mountain top tonight viewing MAR’S next to the MOON!O well the golf course will have to do.
Does this have anything to do with the Mayan codex, they have a prediction on something like this.
Monica, it doesn’t have anything to do with it because it’s a non-event. Mars never has and never will appear as large as the moon. Please see our article on this: http://earthsky.org/tonightpost/astronomy-essentials/will-mars-appear-as-large-as-a-full-moon-in-august-2009
My son’s school gave out a news letter about 8/27 and I really thought…. I had to look it up and I found the truth. You would think they would have the right information.
today is the 27th of August 2009 and since 11:00 pm the moon disappeared and then checking on a clear night at midnight no moon. The moon was bright at 10:00 pm what and why happening?
Well come on people… Who really believed this??? Are there people really that stupid??? Why are the masses so uneducated about these things, Mars as big as the moon.. Hahahahahahahahahahahahahahahahahahahahahahahahahahaha
It is impossible for any planet or star to suddenly appear larger in the night sky – they are sooo far from us that it takes decades/centuries and milleniums for them to appear even slightly closer.
Carlo, you’re correct. Stars are so far away that we don’t see them move – across the scale of human lifespans – in our sky. That’s why you sometimes hear the expresson ‘the fixed stars,’ although really of course in space nothing is fixed. Planets are much much closer than stars, but I can’t think of anything that would cause a planet to leave its regular orbit around the sun and come close to us! The planets’ orbits are very stable and regular.
Carlo,
I second everything Deborah says. I want to add that Mars’ orbit around the sun is slowly but surely becoming more eccentric (elongated). This causes Mars to come slightly closer to the sun at perihelion (the planet’s closest approach to the sun) and slightly farther away at aphelion (the planet’s farthest distance from the sun). Therefore, when the Earth swings between the sun and Mars and Mars concurrently is at or near perihelion, Mars comes unusually close to Earth (less than 35 million miles away) and for a while appears as the second-brightest starlike object in the heavens (after the planet Venus).
Because of Mars’ increasing eccentricity, Mars came marginally closer to Earth on August 27, 2003, than it had in the last 60,000 years. And because Mars’ orbit will continue to increase in eccentricty, Mars will come even closer to Earth on August 28, 2287! The Earth has to swing between the sun and Mars in late August for Mars to come especially close to Earth.
Wow
I haven forgotton all my astonomy studies and wonder if what I thought was Jupiter on the bottom right hand side of the moon the other night was indeed Jupiter, as I was looking at the sky from Italy? Or would the sky look different from Europe versus North America? At approximately the same latitude.
Thank you.