Joined: June 2006
|Quote (Stephen Elliott @ Jan. 25 2006,08:10)|
One question from the full article.
Can you explain how the mass and orbital distance was calculated (as simply as you can please).
It (the article) states that the effect is caused by an order of magnitude depending on the planets mass and distance. How did they calculate both? Could it not have been a different mass planet at a different orbit?
I was listening to NPR this past week (Morning Edition, I think) and they had a discussion about a new paper estimating the number of Earth-like planets in the Milky Way at between 10 and 40 billion. This was defined as "planets between .5 and 2 Earth diameters and .5 and 2 AU". I think the margin of error was 22%.
Anyway, they used the Kepler to look at a tiny region of space and look for dimming of Sun-like stars. The amount of dimming gave a clue to the diameter of the planet and the period of the dimming gave a clue as to the orbital distance.
The lead author said they did not have a method to figure out the density. I would think that you would have to be able to figure out the chemical composition or something.
But I get the trick question- there isn't any such thing as one molecule of water. -JoeG
And scientists rarely test theories. -Gary Gaulin