Posts Tagged ‘orbit’

Full Moon at perigee

Saturday, January 30th, 2010

At last yesterday I managed to get a reasonable shot of the Moon when it was (nearly) full! It was very cold outside and there was frozen snow on my car, which had taken a lot of scraping off. So I could only stay out for a few minutes at a time before coming in to warm up and then go out and have another go.

The photo below was taken at 7.30pm, 10 hours or so before the actual moment of the Moon being completely full. But of course I won’t see that from here. It won’t rise until around 6.00pm tonight, so if it’s clear, it will be at least 12 hours past full when I see it again.

The prominent crater Tycho shows up quite well. Tycho is a lunar impact crater in the southern lunar highlands which was named after the Danish astronomer Tycho Brahe. It’s about 85 kilometers across, and has rays of impact material radiating from it. To see where Tycho is, click on the photo which will take you to my Flickr photostream where I’ve added a note to show where Tycho is. Hold your cursor over the Moon to see it.

I hope to be able to get another shot of the Moon tonight, because today it’s at perigee. This is the nearest point of the Moon’s elliptical orbit in it’s cycle, and today it will be the nearest to us this year, apart from October. It’s distance away is around 359700 km or 223510 miles.

The furthest point of the Moon’s elliptical orbit in each cycle is called the apogee. The more extreme perigees and apogees often occur around January.

Apparently January’s full Moon is called the Wolf Moon which comes from the hungry wolf packs that would howl outside the villages of Native Americans in the coldness of January.

The forecast for tonight is clear skies and very cold, so hopefully I will be able to add another day to my collection of shots of the Moon on every day of it’s visible phases.

Full Moon at perigee


Tuesday, January 27th, 2009

I love watching the International Space Station pass overhead. It’s in a low earth orbit, so it can easily be seen with the naked eye. I love the way it glides serenely across the sky, and it fascinates me to know that there are people living and working on it.

There are several web sites that list it’s visible passes, and it turns up on the dot as predicted. Sometimes it’s not visible at all, but at other times it’s visible once or twice a day, as long as the sky is clear and not cloudy of course. We can only see it when the sun is in the right position for it’s light to be reflected from the ISS, and that’s in the early morning or just after dark.

It only takes an hour and a half for the space station to go all the way round the earth, so I can watch it go over, go into the house and cook a meal or watch a TV programme, and then go out and watch it again and in that time it’s been all the way round the world. Isn’t that amazing! It travels at an average speed of 27,700 kilometres (17,210 miles) per hour, at an approximate altitude of 350 kilometres with 15.7 orbits per day.

The two American astronauts on board were able to watch part of President Obama’s inauguration last week. They weren’t able to see all of the broadcast live, because as the ISS was orbiting the earth at high speed, the signal only arrived intermittently.
See here if you would like to see more information about the International Space Station including who is on it at the moment.