ISS transits

Seanie,whats the problem with your avtar?

<--What, is he not doing the press-ups fast enough??? Drop, and give me 120 more!

:lol:

Hi Chris,
Great map, but it looks like the transit visible from Limerick was yesterday, ah well.
How wide do you think those tracks are, are we talking 1, 2 or 3 miles or 10+ ??

Dave,

The path width depends on the distance that the ISS is from the observer during a transit of the Moon or the Sun, but varies from about 4 miles when furthest (over 400 miles) and down to less than 2.6 miles when closer (250 miles).



Michael Scully

Michael,
Thats a small window of oppertunity!

Well, it was one of the most nerve-wrecking of observations that I've ever made - far worse than a total solar eclipse - but I pulled it off. I saw the ISS fly across the face of the Sun!

The proof is at www.chris.obyrne.com/astro/obsv/20050606-iss.jpg

The observation was made from my apartment - I was pointing the camera at a piece of paper onto which the Sun's image was projected, and hence the distorted shape of the sun. I was more interested in seeing the event than capturing it. The ISS flew slightly "above" the centre of the sun, so I was slightly north of the centre line. The middle image shows the moment just before the end of the transit.

My camera was "only" shooting one frame per second or so, so I was lucky to capture the ISS at all. The timestamps are accurate to a second or so, and the position to about 30 metres. It would appear that the latest calsky.com prediction was very accurate indeed, and it would also appear that the ISS orbit had change slightly since I made my first prediction, as the time of the transit had moved by 40 seconds or so.

Well done Chris, great attempt! Thumbs up!