Showing posts with label overpass. Show all posts
Showing posts with label overpass. Show all posts

Tuesday 8 January 2013

I can see something over New Zealand from Brisbane

The other night I was watching the International Space Station (ISS) over passing Brisbane and by using the ISS tracker I realized that as the ISS disappeared over the horizon it was now above New Zealand. This meant that while I was standing on the road outside my house in Suburban Brisbane, I was able to see an object in the air that was currently located over New Zealand.

Usually when i am looking for the ISS to fly over, there has been minimal cloud cover so it has been easy to spot it, but the other night, there was a lot of cloud cover, so I used the tracker to help me align where to look, it was then that I noticed where the ISS was currently which was over Emerald about 650 km North West of where I was now (Brisbane) , and the ISS had been above the horizon for a few minutes already,

I was pretty amazed that it was still that far away and I could see it, as I continued to monitor the ISS as it approached the horizon I was able to see that it passed fairly quickly South of Sydney and was still easily visible. I lost sight of the ISS when it was about 10 degrees above the horizon behind some trees and noticed that it was about to cross the coast of New Zealand which was about 2300 km away.

Path of International Space Station Click for Larger Image.
I estimate from where it disappeared that it would have been visible if I could spot it early, about 10 degrees above the horizon that it would be visible from the middle of the Gulf of Carpentaria (A in the image). Over B, which is where i was located all the way to the coast of New Zealand (C in the image ) a total distance of 4600 km.

The distances it will be visible from will vary depending on the height of the ISS, the orbit decays (gets closer to earth) and then rockets are used to increase the distance from Earth, I do not know when the ISS flew over if it was high, middle or a low height. The time and hence distance it will be visible for will also vary on how close the overpass is, this over pass was at 62 degrees so was a medium length overpass, a 20 degree overpass (Such as the overpass tonight 8th Jan 2013) would be noticeably less distance. If you are not sure why - get a tennis / basket ball and mark a dot where you are and move your finger over the ball as if it was the ISS.