What the heck is in the air this past week? First we see a simulated image of the sky from Mars go massively viral because people thought it actually showed Earth in the Martian sky, then a clearly Photoshopped pic of two "Suns" setting on Mars gets passed around.

And now a new slice of oddness enters the field: a picture of a planetary alignment over the Giza Pyramids, saying this only happens once every 2737 years. Because planetary alignments and the pyramids play such a large role in New Age/astrological beliefs, there is clearly some sort of spiritual message implied here.

Well, I hate to be a thricely-bursting-bubble person, but here we go again, again. Let me be clear: while there will be an event more-or-less like this in December, and it should be pretty and quite cool to see, the claims being made are somewhat exaggerated. The picture itself isn’t real, and the planets won’t really look like that from Giza. Also, alignments like this happen fairly often, though to be fair getting them spaced out to fit over the pyramids in this way probably is relatively rare.

Busting your Cheops

Here’s the picture making the rounds:

giza_alignment

It clearly shows the three pyramids in Giza, Egypt, with three planets above them. There are various versions of this picture I’ve seen; most are like this with almost no explanation. Some say the planets are Mercury, Venus, and Saturn, and some mention this is what it will look like on December 3rd, 2012, just before sunrise.

First, this obviously cannot be an actual photo if the event hasn’t happened yet! This must be a Photoshop job. That’s fine if it’s only to show what things are supposed to look like, and no one is claiming this is an actual photo.

However, it hardly matters. There are lots of other problems with this planetary alignment claim.

What’s your angle?

The first thing I did when I saw this was ask: is there really going to be a close conjunction of three planets on December 3rd?

The answer is yes! Mercury, Venus, and Saturn will all be within a relatively small distance of each other in the sky on that date. This isn’t a particularly tight configuration like Venus and Jupiter were earlier this year – in this case, they’ll be 14 degrees apart, nearly 30 times the width of the full Moon on the sky – but it’s still pretty nifty.

The second thing I did, though, was ask myself: will they really look like that in the sky as seen from Giza?

The answer this time is no. I used the software planetarium program SkySafari to show what the three planets would look like in the sky before sunrise on December 3rd as seen from the location of the pyramids, and got this:

giza_planetalignment_map

In this picture, the yellow line is the ecliptic, the path of the Sun in the sky through the year. The green horizontal line is the horizon, and the three planets are labeled.

Note the angle of the planets: in the picture going viral, the planets are much closer to horizontal, but in reality the line connecting the planets is at a much steeper angle. It’s nearly vertical, in fact. This may not seem like a big deal, but having the planets closer to horizontal like in the viral picture is more spectacular than what will really happen, exaggerating the claim.

Not only that, but in the pyramid picture the planets are almost exactly on a line, like beads on a string. But as you can see in the picture above, they’re not nearly that colinear. Again it’s looking like the pyramid picture is exaggerating the situation.

Mirror, mirror

I noticed something else funny as well.

Here’s a satellite view of the three pyramids, courtesy Google maps:

gizqpyramids_gmaps

In this picture, north is up and east is to the right. The planetary conjunction happens before sunrise, and as you can see from this satellite view you have to face southeast to see it. That means to see the planets and the pyramids together you’d have to be to the northwest of the pyramids. I added an arrow to the picture here to show that.

From that position to the northwest, the biggest of the three pyramids (Khufu) will be on your left, and the littlest (Menkaure) on your right (this map may help).

You may see where I’m going with this. Look back at the viral picture, and you’ll see they got the pyramids backwards. The little one is on the left (the one in the middle looks like it’s the biggest, but I think that’s a perspective effect due to the telephoto lens used and the angle of the shot, but that’s because it’s built on ground 10 or so meters higher than the big pyramid), which means this picture was taken to the southeast southwest of the pyramids, facing northwest northeast. [Note: a few folks have pointed out I was close, but off a bit. Because the pyramids overlap in the picture, the camera viewpoint is clearly close to being in line with them, making it more like south-by-southwest of the pyramids and facing north-by-northeast. This doesn’t change my argument though: the planets would still be behind you!]

In other words, if you were standing in the spot where the viral photo was taken and faced the pyramids, the planets would be behind you.

Oops.

Again, this may be forgivable if the picture is just supposed to be an example of what you’d see. But it’s more evidence that this event may not unfold exactly as claimed.

Medium rare

Finally, there’s this claim of a planetary alignment only happening every 2700 years or so. That’s not strictly true, but there’s wiggle room here.

Planets orbit the Sun, and we see them moving in the sky (the word planet translates as "wanderer" in the original Greek). Because they orbit the Sun more or less in the same plane as the Earth, we see them passing each other as we all move around (imagine watching a NASCAR race from ground level; the cars appear to approach and pass each other as they go around the track).

venus_jupiter_sxsw2012-225x300

So we see planetary conjunctions all the time, literally every year. At least, with two planets we do. What about three? Well, that happens a lot as well, and when it does it almost inevitably includes Mercury and Venus. Venus and Mercury are closer to the Sun than Earth is, which means two things: a) they orbit it more rapidly, so the configuration changes all the time, making any given conjunction pretty common, and 2) they never get very far from the Sun, meaning you’ll find them near each other in the sky every year or so.

That also means that as another planet – say, Jupiter or Saturn – orbits the Sun, eventually it will pass one or both of these planets in the sky as well. This isn’t a particularly rare event! Mercury, Jupiter, and Venus had a lovely conjunction earlier this year, in March 2012 (though to be fair Venus and Jupiter were quite close, with Mercury being well below them in comparison). The particular configuration claimed – Mercury – Venus – Saturn – happens relatively often as well. In fact, there was one in 2005.

To be fair, the wording of the claim does sound like they’re saying this conjunction combined with the relative spacing over the pyramids is much more rare. That might very well be true.

But even forgiving the inaccuracies of the picture, I find it very difficult to find this anything more than coincidence. There are many, many landmarks on the Earth, and many ways the planets can arrange themselves in the sky. Why not ask how often planets will be near each other and rising near the heelstone at Stonehenge as seen from some particular angle, or aligned with the ziggurats in Central America, or the Moai at Easter Island? And there’s always Manhattanhenge.

The point is, things like this seem almost supernatural, but part of that is because you’re choosing the location after the fact. If you ask how many places there are like this, and how many times the planets "align", it doesn’t seem quite as mystical.

Things are looking up!

Don’t get me wrong: it would actually be pretty cool to see this planetary/pyramid alignment. Someone putting themself at just the right place to the northwest at just the right time might be able to get the three planets aligned with the three pyramids. That would be very pretty, and I’d love to see it personally! But I wouldn’t assign any spiritual significance to it beyond that.

And hey, part of my job is to promote astronomy and get people looking up. If you happen to be in Egypt in December and get some good shots of this event, send ’em to me! I’d love to see them. And if you can think of some other place on our fair planet where this conjunction would make for a nice photo, I’d love to see those, too.

After all, the sky is pretty, and fun to observe, and amazing to understand. In my opinion, just grasping it as it is should be good enough.