When McDaniel College physics professor Jeff Marx, Ph.D, arrived on campus Friday, he had an unexpected phenomenon to discuss with students.
Marx, an astronomy aficionado, spoke to students about a bus-sized meteor that exploded over Russia Friday, no doubt terrifying those who heard the sonic booms and saw the space object flashing through the sky.
The meteor crashed to earth just hours before an asteroid the size of a football field passed close to the planet Friday afternoon.
The meteor and the asteroid are not believed to be related.
Marx discussed with the Times the difference between an asteroid and a meteor, the rarity of having a large meteor reach earth and how many meteors and asteroids are in the solar system.
Q: What's the difference between an asteroid and a meteor?
They are basically the same thing. Believe it or not, it's simply a matter of size. Bigger objects larger than 50 meters are asteroids. Smaller objects than that are meteors.
Q: How rare is it for a meteor to do this kind of damage in a populated area?
I'm no historian on space debris-related injuries, but there are some famous cases of people being hit by meteors. But to the best of my knowledge, this almost certainly represents the largest collection of injuries, albeit indirectly in this case, to an object falling through space. Most of the injuries were from the shock wave and glass and earth-origin debris flying around.
Q: And this definitely didn't have anything to do with the asteroid making a close pass by Earth?
They came from two different parts of the solar system. They just happened to cross paths, and they happened to cross paths very close to Earth.
Q: Most meteors burn up before they make impact, right?
Yes, that's right. A shooting star is an example of a meteor that enters the earth's atmosphere. They glow brightly because they are moving very fast, so they heat up. Tons and tons of space material rains down on earth every day, but most of it is no bigger than dust. Occasionally, something bigger comes through. We see those as shooting stars. Occasionally, something even bigger comes through that catches everybody's attention. This is definitely one of those.
Q: So now what happens?
Well, I've heard they found the impact site, so I'm sure in the coming days, we'll get a lot of analysis about the composition and the origin of this particular rock.
Q: Does the size of the rock have something to do with the chances of entering Earth's atmosphere?
There are some compositional aspects. Some objects stick to themselves better than others. To a first approximation, the bigger it is, the more likely it is to hit the ground. There's a speed issue, too. If it's coming in really, really fast, it might glance off the earth's atmosphere and bounce back into space.
Q: Were students captivated by this?
Absolutely. McDaniel has a pretty active astronomy club ... and the president of the astronomy club is in one of my classes. We talked about it for quite some time. It's a big deal.
Q: Is there a great way to track smaller meteors like this?
Certainly something this size is going to be very difficult to inventory. There's probably millions if not billions of them nearby in our solar system that are so small, they would be very difficult to detect. What's more astonishing is there is big stuff. There are asteroids out there that we know we don't know about.
Q: Is there anything more that could, and should, be done?
An event like [Friday] probably wouldn't have been detected by even a very sophisticated monitoring system. I think it definitely highlights the fact that we need to think a little more critically to inventory at least some of the bigger asteroids at a faster pace than we are doing right now. There needs to be a concerted global effort.