Aerosmith’s “I don’t want to miss a thing” plays softly as you sit and stroke your girlfriend’s hair on what might be the last day you get to spend together. Okay so that’s a scene from Armageddon but it seemed entirely apt.
Tonight a gigantic asteroid is going to whizz past our hapless planet. Although it isn’t going to come close enough to really worry anyone at the moment it is being tracked to see if it might be an issue in the future. Scary stuff, right? Would Bruce Willis even be young enough to protect us now?
So how big is this fella?
The asteroid is approximately 127 foot long. That’s the length of 127 foot-long subs. It is nowhere as big as the chunk of rock that ended the dinosaurs. That one is estimated to have been about 90 miles across but it’s still big enough to do some real damage should it ever hurtle into our humble planet. In fact, far smaller asteroids have caused real peril.
You don’t have to go back far to find an instance either. Back in 2013 a 65foot asteroid exploded over Chelyabinsk in Russia and caused all manner of devastation. The blast caused glass windows throughout the city to explode. This coupled with the bright flash, measured to be thirty times brighter than the sun led to more than 1400 casualties, although fortunately no fatalities. To think this one didn’t even impact on the earth’s surface. The Asteroid blindsided Nasa as it came in masked by the sun.
So why is it notable
The asteroid falls into the range of “near earth objects” that Nasa monitor. Because of the close proximity of its orbit if it gets shifted out of its orbit slightly on a future pass of the earth we might not be so lucky.
How close will it be?
It will be about 3 million miles from earth. So don’t get excited! That might seem a lot, after all the entire earth’s diameter is less than 8000 miles from pole to pole. But when you consider the scale of a solar system it is pretty close. To put it in perspective. The moon is just under 250,000 miles away. And our closest neighbour, Mars is 35 million miles away.
Do we have to worry about stuff in the sky?
Well, incidents like Chelyabinsk suggest that we should. However, the chance of a sizeable asteroid hitting earth are pretty slim. Nasa has the sky fairly well monitored and they don’t think there is anything due to come particularly close in the next 100 years or so. Of course, this can all change.
What causes changes?
In space, there is lots of “space” but there is a fairly prominent asteroid field in our solar system. Colliding with large asteroids or having an orbit thrown out of kilter by one of the planets or moons in our solar system could one day cause an object to alter its course and end up on a collision course with earth.
What would we do?
Well, you have all seen what they have done in the various movies. Build arks, send a team to blow it up in space. Would these approaches work? Probably not. In Armageddon a team drills into the asteroid and inserts a nuclear warhead into it, the explosion splits the astral body in half and the two sections clear earth safely. Studies have shown that the force needed to do that would be 800 trillion terajoules. The most powerful nuclear bomb ever tested on Earth was a “mere” 418,000 terajoules. With so little power the explosion would need to be done before we had even spotted the asteroid! Ultimately if it happens we will probably have to brace ourselves.