Rob Wrote The next challenge is for someone to observe a silhouette transit of ISS across a full (or nearly full) moon. I don't believe anyone has done this yet. At least in this case there's no danger of retinal damage. It's been done! Using a prediction by me, Vance Petriew of the regina centre of the royal astronomical society of canada ( RASC ) observed the iss going across the full moon using his 20 ince telescope. He observed it on Mar 29 around 3:53:43 UTC plus or minus a few seconds :) Here is what he wrote , sorry for the long post. It was pretty cool!!! Man it moves quick! The "blink and you'll miss it" statement definitely holds true. I started setting up the 20" Obsession in front of my garage about 20 minutes ahead of time. There were some small cumulus clouds floating across the sky but nothing too serious. As I was assembling the scope, there must have been a dozen vehicles pass by. I was beginning to think that that 60 lb piece of glass was some kind of vehicle magnet. I guess everyone picked 9:40 PM to be heading somewhere because our street is never that busy. By 9:45 PM I had the light shroud on and did a quick collimation. I headed back to the garage and grabbed the Telrad and noticed that a car had come to a stop just past the telescope. I proceeded over to the telescope as they were backing up. I looked at my watch. 9:48 PM. I thought to myself "Maybe they're just wondering what this big thing was on the street and will move on". As I fumbled to put the Telrad on the scope, I heard a voice from the car ask "Excuse me?". Thoughts poured through my head. "Should I help these people and risk missing the ISS? Every second is crucial." I decided to walk over to the car. They wanted to know how to find a particular street. Since I can never remember street names on the best of days, I told them to turn right and then left and keep looking. They were happy with that answer and I was happy since there was still time left on the clock. I walked back to the scope, put on the Telrad and inserted the eyepiece. Not knowing what to expect, I chose my 31 mm Nagler at 80x so I could see the whole moon. I checked my watch. 9:51 PM. I swung to the scope over to the moon only to find it covered in a thick haze. It looked like it could clear out so I decided to watch the moon through the haze anyway. As I had my eye glued to the eyepiece, I kept getting this urge to check my watch to see how much time was left. I resisted the temptation and stared at the moon trying not to blink. Now, for anyone that's ever looked at the full moon through a full aperture 20" scope, staring at the moon is like looking down the end of a Mag-Lite! Those photons almost hurt! This was one time I was happy to have a little haze. Luckily, I could see the craters start to appear as the haze appeared to thin. After what seemed like a very long time, THERE IT WAS! It was much smaller than I was expecting at 80x. A small, detailed speck in the eyepiece. The speck looked like a 'T' with a lobe on the bottom of it. The top of the 'T' had some small light gaps in it which reminded me of a solar panel mounted to a truss. Because it was moving so quickly, my eye was not able to pick up the movement of it until it crossed the meridian. So realistically, you only get about 1/2 second to pick up details. From my vantage point, the ISS crossed about 1/3 of the way between the moon's equator and the north pole. Very cool! So what would I do differently? I'd choose as much magnification as I could (160x for me) while still maintaining a 30' field of view. Since the moon was still low in the sky, the ISS would have been much smaller than if it were directly overhead. In my case, I think it would have been hard to see at anything less than 50x. Next time, I'd also check my watch with my good eye rather than the blind one :o) Thanks again, Kevin! Vance Petriew Regina Centre His the one who discovered comet petriew last year. Kevin _________________________________________________________________ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www.satellite.eu.org/seesat/seesatindex.html
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