Last Friday (5th June) was a nice night. Although the Moon was almost full and brighten the sky considerably, it was remarkable clear, giving us a great view of constellations such as Leo, Crux, Centaurus and Ursa Major.
The best highlight of the night had to be the appearance of the International Space Station (ISS) as it raced across the sky in its Low Earth Orbit. It was only visible for 2 or 3 minutes but it was an impressive sight watching this bright white dot suddenly appear moving from NNW to SW before disppearing into the Earth's shadow. With a good pair of binoculars I was able to make out its irregular shape, different from stars or planet which look like round dots.
The ISS is orbitting the Earth at an altitude of about 35okm above the ground. It can complete 1 orbit of the Earth in about 90 mins and 15 orbits in one day. As such, if you're in the right time or place its a nice object to try and spot.
Dates and times for ISS sightings can be found on the NASA human spaceflight website:http://spaceflight.nasa.gov/realdata/sightings/
and also on a site called Heaven's Above:http://www.heavens-above.com/?lat=1.29422&lng=103.85376&loc=Singapore&alt=0&tz=MALST
You need to select or find your viewing location (e.g. Singapore) before searching for the timings.
Here is a summary of the more visible sightings over next month (in Singapore):
Mon 8th June: 8:02pm to 8:04pm - moving from WSW to SSW direction - very low
(10-15 degree above horizon) - clear view of SW direction required.
Wed 10th June: 6:16am to 6:19am - moving from South to ESE direction - low in the sky
(10-20 degree above horizon) - clear view of SE direction required
Sat 13th June: 5:58am to 6:01am - from West to NNW (across Northern part of sky, staring 35 degrees above horizon)
Sun 5th July: 8:23pm to 8:27pm - moving from SW to NNE - passing almost directly overhead (85 degree from horizon)
Tues 7th July: 7:37pm to7:42pm - moving from SW to NNE - passing almost directly overhead (79 degree above horizon) - shortly after sunset.
Fri 10th July: 6:14am to 6:20am - moving from NNW to SE - fairly high in the sky (maximium of 51degrees above horizon)
The next time we can see the ISS at the observatory on our Friday night stargazing session is:
Friday 7th August: 7:40pm - for about 1 minute :( - traveling WSW to SSW, only 11 degrees above horizon.
Meaning just after sunset when we'll be setting up we might get another glimpse of ISS, hopefully.
The next "better" sighting on a Friday will be :
Fri 4th Sept - 7:36pm to 7:41pm - 5 minutes!!!! - SW to NNE
We look foward to it :)
The ISS taken from a NASA Space Shuttle (can't remember which shuttle tho) in orbit.