The eclipse from space

[Beano]

Hi guys,

Firstly, I wanted to post this for any people that may not have seen it. It's the first time I have seen this pic so may be good for some newbies like myself. I came across it just browsing Google.

Secondly, a (possibly stupid) question. In the picture. Does the shadow that is cast on earth show the relative size of the moon compared to the earth? If so, that is mind blowing. It is hard at times to get a grasp on the size of planets etc when it is just numbers thrown at you from a book.

The picture is number 5 on the slide show in this link:

All-time top 10 astronomy pictures - Picture Stories- msnbc.com

[jamespels]

Hi beano, thanks for the link, some lovely pics in there! Never seen the eclipse one before - you're right, it's very impressive. Diameters of the earth and moon are about 12,700 km and 3,500km respectively so no, the image does not show the true relative sizes. The reason for this is that the sun is so the bigger than the moon, the umbra (dark bit) of the shadow of the moon is conical in shape, tapering to a point. Where it reaches the earth, I believe it is only about a thousand km across, which is why eclipse totality lasts such a short time.

[Beano]

Ah right thanks for explaining that.

The reason I thought it might be that way is because of the Stargazing Live show that was recently on BBC. Prof. Brian mentioned the moon being the perfect size and distance from the sun to create the total eclipse so I thought maybe the shadow cast upon earth may be the size of the moon but I didn't think to count in the tapering part.

Either way it's a link that deserves seeing!