Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Nick Lister on 06/04/2009 22:30:03

Title: Why has the Earth's orbit not changed?
Post by: Nick Lister on 06/04/2009 22:30:03

Nick Lister  asked the Naked Scientists:
   
Hi Guys, Love the show (http://www.thenakedscientists.com/HTML/podcasts/) - been listening now for 3 years and haven't missed one yet.

In a show (http://www.thenakedscientists.com/HTML/podcasts/) recently somebody said that in the process of burning the Sun loses 4 million tons of mass every second.

Why is it then that the Earth's orbit doesn't change?

I appreciate that this is small percentage of the Sun's total mass but surely over a long period of time this would affect exactly how far the earth is from the sun?

Keep up the good work. Many thanks for a fantastic programme (http://www.thenakedscientists.com/HTML/podcasts/),

Nick Lister from Harrogate

What do you think?

Title: Why has the Earth's orbit not changed?
Post by: RD on 06/04/2009 22:47:53

The Earth's orbit does change with time in an oscillatory fashion (http://en.wikipedia.org/wiki/Milankovitch_cycles#Earth.E2.80.99s_movements) due to the gravitational influence of the other planets.

Title: Why has the Earth's orbit not changed?
Post by: Vern on 07/04/2009 02:13:16

The 4 million tons of mass per second is a very small amount compared to the total mass of the sun. The resulting change in the orbit of the earth is so small that it can't be detected. Keep in mind that there is also an influx of mass into the sun. I don't know the amount, but it could easily be as much as the loss.