Near Earth Objects.

On September 8, a couple of asteroids came whizzing past the earth. The larger was about 10 to 20 meters in diameter, and the smaller 6 to 14 meters across. Not to much of a problem right? Well kind of.

The fact is that this soft of thing happens just about every week. The only difference here is that someone managed to see these things when they were three days out. Most of the time these asteroids just sail on by and we never notice them. I've recently been looking into the science behind all these near earth objects (NEOs) as they are called. And it turns out there are a crap load of them. They really are all over the place. Just floating around up there, waiting for something to smash into.

So how big of a problem would it be if a chunk of rock came hurtling down from space? The truth is that it depends on a large number of variables. The trajectory of the object, its size, its composition, the location of the impact and so on. For example. The 20 meter object that brushed by could have caused massive amounts of damage if it had landed in the middle of a city or in a large body of water. But had it landed in the middle of a desert. Probably most of us wouldn't even have noticed.

So given that we know about all those big objects up there. Are we doing anything about it? Could we do something about it, even if we wanted to? Well yes. There are people tracking these things and trying to determine if they pose a threat to earth. The problem is that finding them and tracking them accurately is very difficult. As for doing something about it. There are a few options. My favorite is the gravity tug. This is essentially where we fly a ship up next to the asteroid and use the gravity between the asteroid and the ship to pull the killer rock off course. The problem with this approach is that it requires us to know the path of the object we want to deflect years, perhaps decades, in advance. And it requires us to launch a vehicle with enough mass to be able to tug the asteroid. If we have far less warning of impending impact. We're probably best to send a few nukes up after it. The purpose of this is not to destroy the asteroid. But instead to alter its course by blasting the nukes near the surface and thus pushing it in the direction we desire.

The fact is that sooner or later we will be hit by a giant rock from space. If it's big enough, and we don't do any thing about it. It could mean our extinction. But if we know it's coming and we get our ideas sorted in time. We can save ourselves. The NEO Apophis seems to be the most likely candidate, that we know of, for a devastating impact. It's about 270m across and shaped like a potato. It's not big enough to do any damage on a planetary scale. But it would certainly be a bad day of it came down. Apophis is going to pass really close to the earth in 2013. There is a small possibility that it will return on a path that may lead it into a collision with the earth or the moon in 2029. Hopefully when it comes by us we can get a good fix on its movement. This should allow for a precise determination of its orbit and a better chance of predicting if it will smash up the earth.

It's weird. I always thought of space as so empty between the planets. And of course it is, compared to anything I can think. But there is still so much stuff up there. Just hanging out. I really hope we stay out of its way.