When Will Mars Appear as Large as the Full Moon?

Astronomical Events for August 27th, 2015

On this day in 2003, the planet Mars came within 35 million miles of the Earth, the closest for 60,000 years. For a short while, it seemed like the world had Mars fever as many looked to the sky in wonder. Despite the unique, brilliant, coppery light that captivated stargazers around the world, many members of the public were decidedly disappointed.

Much of this was due to the internet – or, more specifically, a widely circulated story that claimed that Mars would appear as large as the full Moon on this date. I can personally attest that it has never looked that way.

And it never will.

I wish I could say the story died that year, but unfortunately not. Through the proliferation of Facebook and other social media, it continues to randomly resurrect itself, like an online virus with no known cure, circulated by those who don’t know better and those who simply don’t care.

Part of me wishes that the public would take a moment to think things through. Mars, although a small planet, is still about twice as large as the Moon but is, on average, about 203 times further away. In order for it to appear as large as the full Moon, it would have to be only twice as far. So instead of it being, on average, at a distance of 48 million miles, it would suddenly have to be only 477 thousand miles.

Probably not gonna happen.

Let’s imagine the orbit of Mars (which is nearly circular) somehow allowed the planet to be a hundred times closer than normal (which it doesn’t.) According to the story, the planet will appear as large as the full Moon on a specific date as though it’s a once-in-a-lifetime, never-to-be-repeated opportunity.

In order for this to happen, Mars (and its two moons) would need to suddenly jump across 47 and a half million miles, hang in our sky for about a day (without any apparent effect on the tides), and then magically and mysteriously jump back again.

This is also extremely unlikely.

Part of me wishes it could happen. Honestly. Let’s not be dull. Imagine, for a moment, the impossible happening. Mars suddenly appearing as large as the full Moon, bright and bold, stunningly beautiful, just for one night for all the world to see. For one night, and one night only, it would seem as though we could simply reach out and touch the planet. For one night, while we’re indulging in flights of fancy, maybe humankind would look once more to the stars and imagine what might be.

(For those who like to stop and stare at the stars, Mars is slowly re-emerging into the morning pre-dawn twilight. It will be at its best next May when – and this will be worth sharing on Facebook – the full Moon will appear near to the planet in the sky.)

(Click on an image to enlarge. Images courtesy of Mobile Observatory.)



Other Astronomical Events:

00:13 UT – Jupiter is at apogee. Distance to Earth: 6.399 AU. (Magnitude -1.7, diameter 30.8”. Leo, not visible.)

07:33 UT – The waxing gibbous Moon passes dwarf planet Ceres. (Ceres: magnitude 7.6. Sagittarius, evening sky.)

The constellation Aquarius (the Water Bearer) culminates at midnight tonight. (Naked eye, all night.)



Events in bold involve objects and/or events that are visible with the naked eye.

All times are in Universal Time (UTC). To convert the time to your timezone, click here.

Adapted from 2015: An Astronomical Year, available in Kindle and paperback formats from Amazon in the US, Canada and the United Kingdom.

2015 An Astronomical Year (Kindle Edition) 2016 An Astronomical Year Paperback Cover 2016 The Night Sky Sights The Astronomical Almanac 2015-2019

2015: An Astronomical Year

2016: An Astronomical Year 2016: The Night Sky Sights The Astronomical Almanac (2015-2019) The Amateur Astronomer’s Notebook (Pocket Edition)

(Kindle & Paperback)

(Kindle & Paperback) (Kindle & Paperback) (Kindle & Paperback)


Amazon – US

Amazon – US Amazon – US Amazon – US Amazon – US
Amazon – UK Amazon – UK  Amazon – UK Amazon – UK

Amazon – UK

Details of all available books across the world can be found here or by visiting the author’s page on Amazon. If you have any comments or questions, please feel free to contact me at astronomywriter “at” gmail.com


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