THAT'S GONNA LEAVE A MARK

by Bob Walsh

Later on this year the people who brought us TANG and good quality battery operated tools are taking the first step to save us from killer asteroids.

There have been five extinction level events in in the four billion or so years the earth has been around.  At least two of them were almost certainly caused by asteroid impacts.  One of them, about 250 million years ago, killed off 96% of the things on the planet.  That would be a bad thing to happen now.

At any rate NASA is going to crash a satellite the size of a washing machine deliberately into a small asteroid in about 15 months.  The asteroid in question is one of a pair orbiting each other.  They are called Didymos and Dimorphos.  NASA believes that if they can hit it hard enough it will disrupt the rotation cycle which will be visible from earth.  The idea is they want to see how feasible it is to use basic kinetic energy to alter the flight path of an asteroid.  The space craft will be doing about 4.1 miles per second so the impact will not be inconsequential, though Dimorphos is thought to weigh about 5 million metric tons.  

The risk of a major asteroid hit is not zero   There are 1,400 known near earth objects of a size that could cause us trouble if they hit.  One of them, the asteroid Apophis, will cruise by earth in April of 2029.  It will miss us by about 19,000 miles, which is less than the orbital height of geostationary communication satellites.    

 

The rock is about 1,500 feet across so it could give the planet a large owie if it hit.