Buckle up, folks, because NBC’s miniseries Meteor (2009) is must-see TV at its best. Or at least the best NBC can do these days. In the opening shot, we see an asteroid get hit by a smaller object, then quickly fade to a brightly lit observatory on the Baja Peninsula in Mexico. Except that it’s really the 60″ telescope on Mt. Wilson in Los Angeles. Of course Doc Brown is looking through the eyepiece of the telescope, frantically jotting down equations and checking references on one of those see-through whiteboards that only exist on TV and movies. The Doc and his beautiful young assistant Imogen determine that the thing headed for Earth is asteroid 114 Kassandra, a main-belt asteroid that’s ~60 miles across. It must’ve been hit by something to knock it out of its orbit. Let’s look at the asteroid belt, courtesy of NASA:
Main belt asteroids orbit the Sun between Mars and Jupiter, roughly 2 and 3 times as far from the Sun as the Earth. 114 Kassandra is around 2.6 times the Earth/Sun distance, and, while it’s orbit is eccentric, it never gets closer to the Earth’s orbit than around 140 Million miles. It’s certainly possible that an impact on an asteroid could cause its orbit to change, though it would’ve had to happen quite a while ago to get that asteroid to move a minimum of 140 Million miles. The 114 in front of Kassandra’s name means that it was the 114th main belt asteroid discovered[ref]Generally, especially for large, main-belt asteroids, you can think of the number as a proxy for size. This isn’t strictly true; other factors weigh into it like albedo (reflectivity) and shape. It’s just a good rule of thumb.[/ref]. Someone would notice if this thing had been knocked out of its orbit several years ago.
Our heroes alert JPL scientist George Costanza, who informs us that Kassandra really is a main belt asteroid, but then tells us its orbit never gets closer than 400,000 miles! For crying out loud, NBC, you spent a few bucks on this thing. The cast has a lot of people I can make fun of household names in it. You could hire a science advisor. Or an intern. Get an unpaid intern to check the wikipedia. The Moon is, on average, 238,000 miles from the Earth. Are you really saying that the asteroid belt is less than twice as far as the Moon? If it were that close, the brightest several hundred things in the sky after the Sun and Moon would all be asteroids! Heck, the biggest main belt asteroids would be resolvable as discs to the naked eye!
In the film, Kassandra is first seen 24-48 hours before impact. Now let’s do some math. You can skim this part if you’re not familiar with how visual magnitudes work. For solar system bodies, determining their brightness in the sky is a little different than for things further away, since most things further away can’t be resolved spatially, nor do they go through phases. The apparent magnitude of a solar system body is given by this equation:
where H is the solar system absolute magnitude (8.275 for Kassandra), d_BS is the distance between the Sun and the object in question, d_BO is the distance between the observer and the body, p(X) is the phase integral, which has to do with how much of the object appears to be illuminated from the observer’s perspective (assumed to be around 2/3)[ref]We’re making the assumption that the asteroid is approximately spherical. This is not necessarily a good assumption, but any other assumption makes the movie science even worse.[/ref], and d_0 is the distance between the Sun and the observer.
Objects become visible to the naked eye at an apparent magnitude of around 6. If we make a few reasonable assumptions, we can solve the equation above for d_BO, the distance that Kassandra would have to be from the Earth for it to be visible with the naked eye[ref]If you want to know the assumptions I made, email me.[/ref]. The answer is: around 20 Million miles. Assuming George was completely wrong with his distance of 400,000 miles earlier in the film (he was awakened in the dead of night by the phone, after all), then either everybody on Earth is completely blind or Kassandra is traveling at at least 416,000 miles per hour if it is to get here in 48 hours. If, however, George’s distance of 400,000 miles was correct, Kassandra need only be traveling at a pokey (by astronomical standards) 8,000 mph. But if Kassandra were only 400,000 miles away, we can use the equation above again to determine how bright it would be: V = -3.1. Sirius, the brightest star in the sky, is V = -1.46. Punch line: in its “normal” orbital distance of 400,000 miles, Kassandra would be by far the brightest object in the sky after the Sun, Moon, and Venus.
You kids today may not fully appreciate this, but back in the 20th century, we didn’t all carry around powerful multicore computers running a unix-variant OS in our pockets that are also capable of high-speed wireless communication via a variety of protocols. That’s why you can forgive movies like 1998’s Deep Impact, where the scientist hops in his car to warn people about the impending disaster. But in this film, released around the same time as the iPhone 3GS, why don’t they just stay at their observatory? (Note: Imogen the assistant actually asks this question to Doc Brown after they’ve been driving for hours. They must’ve had a lot to discuss!) But since they’re driving to save the day, we’d better kill off the Doc! (In a hit-and-run, no less.) Naturally, he’s the only one capable of the complex orbital calculations that can avert the impending disaster.
Like many of the other made-for-TV movies, the impending destruction by asteroid isn’t the only plot element. There’s Sheriff Mike Hammer, violent criminal Merle, and Detective Rocketeer, all tied up in some convoluted plot about… something. We’ll come back to the plot later if we have to.
Meanwhile, a wind blows across the Moon, wiping out the astronauts’ footprints. I guess this makes sense, given that Kassandra started out only 400,000 miles away, though, as we discussed, it’s moving at at least 8,000 mph, so the “wind” would likely be a bit more destructive. Harbinger asteroids are falling to the Earth as well. (There’s no such thing as a harbinger asteroid.) In charge of the investigation is General Winston Zeddemore, sans proton pack, who tells us that an interplanetary dust storm is heading our way. So now we have three weird things to explain. Buckle up.
By now I don’t need to tell anyone that the plan is to nuke the asteroid, although I think it might take more than one missile:
Don’t look now, but I’m going to say something positive about this movie! The trajectory of the asteroid pieces as they fall to Earth is the same! They’re not just coming from all over the sky! Aaaaannnd then a piece hits a moving school bus. Paging Dr. Murphy. Please report to the asteroid tracking office immediately.
When an asteroid takes out the asteroid tracking satellite, the nuking process is delayed. If only the National Science Foundation had a reasonable budget for near earth object tracking. Write your congressional reps!
Speaking of which, a National Guard troop takes out a meteor chunk over San Francisco with a one-person shoulder-mounted rocket launcher. I don’t even know how to begin calculating how improbable that is, so I’m gonna go with “very”.
Back in the real world, Imogen the assistant, the only one who can save the day with her knowledge of orbital calculations now that Doc Brown is dead, encounters an evil Mexican sheriff who… attempts an unspeakable act… and she kinda… well… she beats him to death with a fire extinguisher then puts three slugs into his associate. And you thought Michael Rooker would be the most evil character. Nope, turns out this movie is sexist and racist.
We finally see Kassandra, hovering right above the Earth. They nuke it, but it turns out the Doc had been wrong! The original comet impact split the asteroid in two, and the second, larger piece is still headed our way! And we used up all our nukes on the first piece! WHAT WILL WE DO?!?
End of part 1. I mentioned this is a miniseries, right?
Ok, I’ll spare you the details. The plots eventually collide, with Rook abducting Imogen for unimportant reasons. She’s saved by The Rocketeer, and is able to contact HQ. As the larger chunk of Kassandra is entering the atmosphere she gets them to alter the course of the remaining nukes, deflecting Kassandra into the Sun.