Among other topics on this episode is the Asteroid challenge, can we find all asteroid threats to Earth. There is also coverage of a memorial to Neil Armstrong.
On the asteroid topic: I get listings of newly discovered and re-discovered asteroids. I like to scan the listings looking at the semi-major axis “a”. We can quickly figure the period of the asteroid in years:
Period = The square root of the cube of the semi-major axis. Simple and quick on almost any calculator, you can even do it in Google. A period of one year means the asteroid has the same orbital period as the Earth, not necessarily the same orbit or anything like that, simple that if it is at let’s say Point X today, a year from now it will be pretty close to Point X again.
There have been some pretty good finds, a couple with orbital periods of better than 80 years. The other day I ran across one with a semi-major axis of 0.849 AU and that is an orbital period of 0.782…years or 285 days. When you see an orbital period of less than one, you know it has a period of less than a year so its orbit is contained inside of that of the Earth.
The asteroid 2010 NG1 does come by and gets kind of close to us on occasion but not terribly so. However a close approach to Venus does seem to be in the offing on 25 Feb 2014. It won’t hit or anything and I’m still trying to sort out how close but you can get an idea by looking at the JPL Orbital Diagram.