Solar Storms

21 04 2009

The sun is our constant companion; it supplies heat and light to us and keeps our small blue/green world from freezing. However, as serene as the sun seems on a lazy summers day, a close look at its surface tells a very different story. Read the rest of this entry »



16 03 2009

On a typical night, looking into the sky, you can see somewhere between 500 and 6000 stars, depending on how dark your night sky is. If you live in a reasonably dark area, you may be lucky enough to see a faint, diffuse band stretching across the sky, from horizon to horizon. This band, known as the Milky Way, is the plane of our home galaxy.

It was Galileo who discovered that this band consisted of an almost uncountable number of stars, after he turned his telescope to the sky. Prior to this, it was believed that the Milky Way was a ‘cloud’ that spanned the entire sky.

360-degree photographic panorama of the Milky Way. (Digital Sky LLC)

360-degree photographic panorama of the Milky Way. (Digital Sky LLC)

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Build your own Newtonian Reflector…

11 03 2009

Well done everyone who helped build the class telescope last night – I hope you all enjoyed the experience of putting your very own telescope together and getting a chance to view a lovely full moon through it too.

If you want to get hold of your own kit, it is available from here:, although stocks are often low, so order now!

Carl Sagan – Pale Blue Dot

11 03 2009

pale_blue_dot_uitsnedeThe Pale Blue Dot is a photograph of planet Earth taken in 1990 by Voyager 1 from a record distance, showing it against the vastness of space. Both the idea for taking the distant photo and the title came from scientist and astronomer Carl Sagan, who also wrote the 1994 book of the same name. In 2001, it was selected by as one of the top ten space science photos.

The photo was taken as Voyager was 3.7 billion miles from Earth. Read the rest of this entry »

The Galileoscope™: An IYA2009 Cornerstone Project

10 03 2009

The Galileoscope™ is a high-quality, low-cost telescope kit developed for the International Year of Astronomy 2009 by a team of leading astronomers, optical engineers, and science educators. No matter where you live, with this easy-to-assemble, 50-mm (2-inch) diameter, 25- to 50-power achromatic refractor, you can see the celestial wonders that Galileo Galilei first glimpsed 400 years ago and that still delight stargazers today. These include lunar craters and mountains, four moons circling Jupiter, the phases of Venus, Saturn’s rings, and countless stars invisible to the unaided eye. Read the rest of this entry »

The Sun – lifecycle

3 03 2009

Over the course of a human lifetime, the Sun is an unchanging, constant companion – bringer of light and heat and champion of the day. It is often tempting to believe that it will always be here and always has been here. The truth, however, is quite different.

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Telescopes and Lenses

24 02 2009

This is an exciting time in which to become an amateur astronomer. Never before have novice stargazers been presented with such a vast array of telescopes and accessories to pursue their hobby. Naturally, this brings the burden of choice. A bewildering variety of instruments make it difficult for the uninformed consumer to make the right decision. That’s what this entry is all about – to explain the options so you can choose the telescope that’s best for you.
Before examining the different types of telescopes available, it’s worthwhile illustrating some basic principles in order to understand how they work. The most important aspect of any telescope is its aperture, or the diameter of its main optical component, which can be a lens or a mirror – the fatter the tube, the larger the aperture. A scope’s aperture determines its light-gathering ability and its resolving power (the ability to see fine detail in an image).
What does this mean in real terms? With a 6-inch telescope, you can discern lunar craters that are as small as a mile across, which is half the size of those visible in a 3-inch scope under similar conditions. However, the same two instruments turned toward a faint galaxy on a moonless night would tell a different story. The 6-inch gathers four times the light of a 3-inch, not twice, so the galaxy would be four times brighter in the larger instrument. How is that? A 6-inch telescope has four times the light-collecting area of a 3-inch. Read the rest of this entry »