Chasing shadows on the Moon

Odd as it may seem, the Moon is often overlooked as an observing target by amateur astronomers. They curse it for drowning out fainter objects such as galaxies and nebulae and fail to recognise its own fascinating qualities. But the Moon, our planet's natural satellite, must be the world that we can study in the greatest detail. Indeed, we can see more of it more easily than we can the Earth from any one spot at any one time. As the Moon circles the Earth, it keeps essentially the same face pointed towards us. That face is continually changing its expression however thanks to the differing levels of light and shade. We all know that the Moon goes through a range of phases during its 28-day orbit. When the Moon is full, it presents more of itself to us than at any other phase. But, perversely, it is then also at its least revealing. The reason is that the Moon is then reflecting the Sun's light straight back towards us with an absence of any shadows. The result is that is shines like a brilliant, almost featureless, disk apart from the dark lunar seas, or maria. Contrast that with the view when it is at a crescent or half-moon phase. The different angle of sunlight on the lunar mountains and craters produces shadows that bring them into sharp relief. It can be fascinating to watch the way these features change their appearance from night to night as they move more and more into daylight. I took a couple of photos of the Moon this week which show what a difference 24 hours make on the lunar surface. They were taken with a Nikon Coolpix 885 camera attached to a 32mm Plossl eyepiece on a Meade ETX90 telescope. ©PAUL SUTHERLAND, SpaceStories.com

Catch Mercury in the morning

There is a particularly good opportunity to view Mercury at the moment. Usually the closest planet to the Sun is lost in the solar glare. But during late November it lies at one of its elongations - a time when it appears at its furthest from the Sun. Mercury is currently rising early enough before the Sun and at a steep enough angle for it to be seen as a bright "star" in the morning twilight. Find it by looking directly to the south-east soon after the first signs of dawn appear. The planet is actually positoned in the constellation of Libra, not far from the wonderfully named star Zubenelgenubi. You will need to be quick to catch Mercury. It was at its greatest western elongation, 20 degrees from the Sun, on November 25 when it was rising around an hour and a half before sunrise. But it is now closing in and preparing to nip round the back of the Sun again in its 88-day orbit. Through a big telescope, Mercury looks like a gibbous moon. It will be lost in the Sun's glare again by mid December. Before that, use binoculars to spot it close to Jupiter and Mars in the twilight between December 9 - 11. The photo is of an evening elongation of Mercury that I took in March 2004 from Sandwich, Kent. ©PAUL SUTHERLAND, SpaceStories.com

Another blast from the Leonids?

A strong outburst of shooting stars is predicted to occur over the UK and Ireland this weekend. Astronomers say western Europe will be the best part of the world to witness a dramatic show before dawn on Sunday, 19 November. It will happen as the Earth ploughs through a stream of dusty debris left by a comet called Tempel-Tuttle. The meteor shower, called the Leonids, produced intense displays between 1998 and 2002. The show has been waning since each November as our orbit crossed that of the comet dust. But this year, experts say the Earth will pass through a particularly dense, narrow, ribbon of dust before dawn on Sunday. Meteor expert David Asher of Armagh Observatory, Northern Ireland, says the outburst will occur for around half an hour from about 4.30am until 5am. He predicts that UK and Irish observers with clear, dark skies will see a rate of 150 meteors an hour. In 1998, the Leonids produced an amazing night of fireballs because the Earth passed through a stream of rock-sized debris ejected from the comet in the 14th century. This year we will encounter a trail of finer dust that was left by the comet on a much more recent passage in 1932. The shower is called the Leonids because the meteors will all appear to come from the direction of Leo in the sky. Britain will be on the side of the world facing almost directly into the oncoming shower which will give a big boost to observed rates. For more details of the shower, visit the SPA's November meteor page. Eastern parts of North America might catch some of the activity at around 11.45 EST on Saturday night (18 November) but the meteors will be skimming into the atmosphere at a low angle and so will be less frequent. More here from Sky & Telescope. ©PAUL SUTHERLAND, SpaceStories.com

Planets cluster around the Sun

If the sky seems rather empty of planets at the moment, it is because so many are clustered close to the Sun. Amateur astronomers can rise early to catch beautiful Saturn rising late in the night. But meanwhile a rare conjunction of four bright planets has been visible with space telescopes. The worlds - Jupiter, Venus, Mercury and Mars - were all too close to the solar glare to be seen from Earth. But the close grouping could be seen in single images from a solar satellite called SoHo (the Solar and Heliospheric Observatory) as it monitored our parent star over the weekend. Last week, Mercury pased in front of the Sun in a rare transit which was visible from America and the Pacific region. Picture: SpaceWeather.com. ©PAUL SUTHERLAND, SpaceStories.com

Mercury to dash across the sun

A rare transit of Mercury will send a dark spot gliding across the face of the sun on Wednesday, November 8. For nearly five hours, the closest planet to the sun will appear as a tiny silhouette against the solar disk. The transit does not occur until after sunset in the UK but some British astronomers have travelled abroad to see it. Good views will be had from the Americas, Australia, Japan and the Pacific. Webcams are being set up to broadcast the event live on the internet. One of the best will come from mountaintops on Hawaii and can be viewed here. As well as live images, the site will compile and show time-lapse movies of the spectacle. If you live within the region of visibility, remember the safety rules for viewing the sun. Mercury will only be visible with a telescope but you must use an approved solar filter. A safer method is to project the sun's disk through your telescope onto a piece of white card. The next transit of Mercury visible from the British Isles will not occur until May 9th, 2016. Only the early stages will be visible before the sun sets. The last visible from the UK was on May 7, 2003. Transits of Mercury only happen in May or November at intervals of seven, 13, or 33 years. A Nasa page about the phenomenon is here. The photo is of a projected image of the 2003 transit, by Paul Sutherland. Mercury is the tiny dot to the left - the other blot is a sunspot. ©PAUL SUTHERLAND, SpaceStories.com