Position of the planets on August 27, 2010. Click for a larger version

The Mars Hoax is beginning to make the rounds again.  It just won’t go away.  I’m sure you’ve heard it.  Mars is going to be the closest it will ever be (or some such claim) and it is going to be as large as the full Moon on August 27th!  I’ve even heard all this was going to take place at 12:30 am “so get your cameras ready” and they were going to be close together, oh what an event.

Here’s the real deal.  No-No-No-No!!  Just go ahead and Google for The Mars Hoax or use any other search engine you please.

Let me take a crack at it too:

Let’s do away with the last bit first.  Mars will not be above the horizon at 12:30 am on August 27th.  Pretty hard to get that great photo if the planet can’t even be seen eh?

The part about Mars being closest in who knows how long.  The image above (click to enlarge) shows the relative positions of the inner planets on August 27, 2010.  Note the orbital tracks in the image. The Earth and Mars are a long ways apart on that special day; in fact the next time we will be anywhere close to Mars will be in April of 2014 and we will still be  92,750,760 km or  57,632,650 miles apart!

Let’s compare August 27, 2010 data:

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Now I know some of you are going “but Tom, your numbers aren’t exact”, yeah I know but they are pretty close.

You can see by not only the image, but looking at that little chart, the angular size (the apparent size of the pair), it’s not even close!  The magnitude shows Mars will be dimmer as seen by us – the Moon is going to be 90 odd percent full too.  Small and comparatively dim is not large and bright.

Could we on Earth ever see Mars as big as the full Moon?  No, but exactly would it take?

We would have to move Mars much closer to us.  In order for Mars to appear to be the same size as the Moon we would need to move the orbit in – a lot!  From 320,000,000 km to 801,000 km, (that’s from 198,838,782 miles to 497,670 miles for the metrically challenged).  Can you imagine what that would do to our tides, to say nothing about other things like rotational and orbital rate?

The other choice would be to move the poor old Moon so its angular size was 4.39″ to match Mars.  Moving the Moon from 408,530 km (253,360 miles) to a whooping 163,320,000 km (101,490,000 miles) away would do it.  I almost think that would be worse for the Earth than moving Mars closer.  I can envision the poor Earth spinning like a raw egg, ahhh, eggs and astronomy, no balancing needed.

So hopefully this will dispel any notion Mars and the Moon will ever appear to be the same size to any person in their right mind as viewed from Earth.

and….I do like Orson Welles