Bad Astronomy. Misconceptions and Misuses Revealed, from Astrology to the Moon Landing 'Hoax'

you really want to buy a star from them?

Perhaps, after all this, it’s time for me to come clean. I’ll admit here that I have “my own” star. Many years ago my brothers bought it from the ISR and gave it to me as a birthday gift. That star — named Philip Cary Plait — is located in the constellation of Andromeda, and is about 100 times too faint to be seen with the unaided eye.

I lost the original certificate for the star years ago and out of curiosity I called the ISR to see if they could tell me where the star is. They were surprised; evidently, and ironically, it was one of the first stars sold by the company in their first year of business, but they were able to give me its coordinates. They were not very accurate but I was able to find it on a digital star map, which can be seen in the photograph.

Can you spot it? It’s the one in the center. You can see there are many other stars in that field, including a lot that are brighter. None can be seen with the unaided eye, by the way. The kicker is that “my” star already has a name — BD+48? 683. For about 130 years this designation has been catalogued in the German Bonner Durchmusterung catalog used by practically every astronomer on the planet. In the end, I think they have the edge in the naming business.

The star “Philip Cary Plait” — a/k/a BD+48? 683 — lurking not very obviously in a field of thousands of other stars. The image shown is 1 degree across, roughly twice the size of the full Moon on the sky.

Image © 1995–2000 by the Association of Universities for Research in Astronomy, Inc. The Digitized Sky Survey was produced at the Space Telescope Science Institute under U.S. Government grant NAG W- 2166. (The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into compressed digital form with the permission of these institutions.)

So if you really want to buy a star, I urge you not to throw your money at these companies. You could just go out and buy some nice graphics software and make your own star-naming certificate, then pick any one you want, even the brightest in the night sky, and it’s just as official.

And I have an even better idea. Most observatories and planetaria are strapped for cash. Instead of buying a star, you could give them a donation to sponsor educational programs. That way, instead of just having one star you’ve never seen named for you, you’ll be giving hundreds or thousands of people a chance to see all the stars in the sky.

Remember — the stars are for everyone, and they’re free. Why not go to your local observatory and take a peek?

24. Bad Astronomy Goes Hollywood: The Top-Ten Examples of Bad Astronomy in Major Motion Pictures

Whoosh! Our Hero’s spaceship comes roaring out of a dense asteroid field, banks hard to the left, and dodges laser beams from the Dreaded Enemy, who have come from a distant galaxy to steal all of Earth’s precious water. The Dreaded Enemy tries to escape Earth’s gravity but is caught like a fly in amber. As stars flash by, Our Hero gets a lock on them and fires! A huge ball of light erupts, accompanied by an even faster expanding ring of material as the Dreaded Enemy’s ship explodes. Yelling joyously, Our Hero flies across the disk of the full Moon, with the Sun just beyond.

We’ve all seen this scene in any of a hundred interchangeable science-fiction movies. It sounds like an exciting scene. But what’s wrong with this picture?

Well, everything, actually.

A lot of science-fiction movies are good fiction but bad science. Most writers have no problem sacrificing accuracy to make a good plot, and astronomy is usually the first field with its head on the block. How many times have you sat through one of these movies and shook your head at the way astronomy was portrayed? I spent a lot of my youth in front of the television watching bad science-fiction movies, and while they did help foment my interest in science, they also put a lot of junk into my head. So in the name of astronomers everywhere, I have compiled a Top-Ten list of Bad Astronomy in movies and TV. Some of these examples are specific and others are generalizations culled from hundreds of movies I’ve watched late at night or on Saturday mornings. The results are compiled into the scene above.

Let’s pick apart that scene and find out just where it goes wrong. Go ahead and make some popcorn, sit back, drink some soda out of an oversized cup, and enjoy the show. And please! Be considerate of others; keep the noise to a minimum. Speaking of which…

1. Whoosh! Our Hero’s spaceship comes roaring out…

Well, as they say, “In space, no one can hear you scream.” Sound, unlike light, needs something through which to travel. What we hear as sound is actually a compression and expansion of the matter — usually air — through which the sound wave is traveling. In space, though, there’s no air, so sound can’t propagate.

But we live on a planet with a lot of air and we’re accustomed to hearing things make noise as they go past us. Cars, trains, baseballs: they all whiz through the air as they pass us by. If we see something moving past quickly and quietly, it looks funny. Andre Bormanis, writer and science advisor for the Star Trek television series, confirmed a rumor I had heard for years: Gene Roddenberry, creator of Star Trek, wanted the original starship Enterprise moving silently through space. However, pressure from network executives forced him to add the familiar rumble and the “whoosh” as it flew past. In the later seasons, though, he removed the rumble. The “whoosh” in the opening credits stayed, though, probably (I’m guessing) because it would have cost too much to change the sequence. I guess the budget for space travel is tight even 200 years in the future.

There is a situation in which sound can propagate across space, when sound waves travel through an interstellar gas cloud. Even though they look thick and puffy, like the clouds after which they are named, a typical nebula (Latin for “cloud”) is really not much more substantial than a vacuum. The atoms in the vast cloud are pretty far apart, but even a few atoms per cubic centimeter adds up when you’re talking about a nebula trillions of kilometers thick. These atoms can indeed bump into each other, allowing sound to travel through the cloud.

Most processes that create “sound” in these nebulae, though, are pretty violent, such as when two clouds smash into each other or when a wind from a nearby star traveling at several kilometers per second slams into the nebula and compresses the gas. These processes generally try to push the gas around much faster than the nebula can react; the atoms of gas “communicate” with each other at the local speed of sound. If some atom is sitting around minding its own business and another one comes along moving faster than sound, the first atom is surprised by it. It’s literally shocked: it didn’t know what was coming. When this happens to a lot of material it’s called a shock wave.

Shock waves are common in nebulae. They compress the gas into beautiful sheets and filaments, which we can “ooohh” and “ahhh” at from our nice comfortable planet safely located a few hundred light-years away. I imagine property values near the Orion Nebula are at a premium. The view is unparalleled, and if you choose your site correctly the ghostly whispers of swept-up atoms will remain unheard.

2… of a dense asteroid field…

Ever heard the term “asteroid swarm”? Well, it’s more like an “asteroid vacuum.” In our solar system the vast majority of asteroids are located in a region between Mars and Jupiter. The total amount of area defined by the circles of their two orbits is about one-quintillion (10¹⁸) square kilometers. That’s a lot of room! Astronomer Dan Durda puts it this way: imagine a scale model of the solar system where the Sun is a largish beach ball a meter (1 yard) across. The Earth would be a marble 1 centimeter (1/2 inch) in size located about 100 meters (roughly the length of a football field) from the Sun. Mars would be a pea about 150 meters away from the Sun, and