Tuesday, April 16, 2024
HomeAll FeaturesAstronomy with Brian WatkissPerfect time to see stars of the satellite world

Perfect time to see stars of the satellite world

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Amateur astronomer Brian Watkiss peers into the Village night sky.

June is a month when, to an astronomer, it never really gets dark. But it is a perfect time for spotting satellites. Some specialist equipment is needed; I would recommend a good deckchair (the old fashioned wooden sort is perfect), a few friends and perhaps a warming drink.

Satellites are very easy to see; they all look like stars drifting across the sky at about the speed of a passing aircraft but without the flashing anti-collision lights or the red and green navigation lights. Some are bright, most are not and the majority vary in brightness.

Switch off all the lights, especially security lights, sit back and look at the sky as soon as it starts to gets dark. On any night, you should soon see a “star” wandering across the sky. It may come from any direction and may vanish before you have time to tell anyone but don‘t worry, there‘ll be another one along any moment.

The real “stars” of the satellite world are the Space Shuttle and the International Space Station (ISS). The ISS is the largest man-made object ever to orbit the Earth and is an amazing sight, and one to which you can easily become addicted. Like all satellites, it is only visible when it is in sunlight but the sun has set for the observer.

Fortunately, some clever people have set up a website to calculate exactly when you can see it. Go to www.heavens-above.com, and under “Configuration”,  “select from database”, select “UK” then type in “Alvechurch”. Under “Satellites” select “ISS” and if the Space Station is visible, a table will appear, giving times and directions.

I prefer the late evening sightings to the early mornings and the longer it is on view, the better. As the ISS never gets further north than Alvechurch, it will usually appear from the west or south west and in the “Max altitude” column, the number under “Alt” gives an idea of how high in the sky it will get. Above 60 is nearly overhead and below 15 is scraping the rooftops.

Clicking on the date will produce a sky chart showing the track across the sky. 

If a Space Shuttle is in orbit, its times will be listed under STS. On its way to the Space Station, the times can be unreliable but if you catch it when it undocks from the ISS, it can be spectacular. It is a quirk of orbital mechanics that when you fire your engine in space to slow down, you drop into a lower orbit and actually speed up. So, just after undocking, the Shuttle will be leading the ISS and getting further away.

After a bit of practice, you will soon get the hang of everything in the Heavens Above tables and can amaze family, friends and publicans by showing them the ISS in space.

Even more spectacular are Iridium Flares, also predicted on the website. This is sunlight reflected off the shiny aerials of the network of Iridium telephone satellites. They only last a few seconds, so you will need some practice to know exactly where to look but they are well worth the effort.

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