Saturday, 9 August 2014

10 August 2014 - The largest Full Moon for the Year


Image of the Moon taken over Table Mountain, credit: Dr Steve Potter, SAAO.

Source: SAAO

Did you know that the Moon travels around the Earth in an oval shaped or elliptical orbit rather than a circular one? The average distance between the Earth and Moon is 384,400 km. However, because of its elliptical path, the distance to the Moon varies depending on where it is in its orbit around Earth. At its closest point or perigee, the Moon is about 50,000 km closer to Earth than at its most distant point (called apogee).

Full Moons that occur when the Moon is close to or at perigee are called Supermoons and they appear slightly larger and brighter than usual. There is nothing magical about a Supermoon, it is simply a coincidence that full moon has occured when the Moon is near to its closest point to Earth. Just like an aeroplane looks larger the closer it is, so does the Moon.

Read more...

Thursday, 7 August 2014

Meteorites: A Southern African Perspective


Meteorites are the remnants of meteors from outer space that have survived the corridor of fire through Earth's atmosphere and landed on our planet. Rare, and bearing secrets about the formation of our Universe, these 'treasures from space' have fascinated people ever since they were first identified in the late 18th century as extraterrestrial arrivals.

This jam-packed book by enthusiast and collector Ronnie McKenzie introduces the topic in straightforward language and is richly illustrated with some 200 photographs and diagrams. It discusses how to identify meteorites, where they come from and where they have landed on Earth, the many different types, and how to set about collecting them. It also dispels some of the myths about these stones, and presents some infamous meteorite scams.

A handy basic guide for those new to the topic, and for anyone interested in entering the field of meteorite collecting.

Sunday, 3 August 2014

Deep-Sky Hunter Star Atlas


"Deep Sky hunter" is a printable deep sky atlas, designed for serious deep sky observers. It features stars down to 10.2m and DSO down to 14.0m.

This is my second release of a deep sky atlas. It is much more detailed, and covers entire sky with 101 portrait oriented pages. Manual post-editing was performed in order to ensure readable and non-cluttered charts. In addition, the atlas features 8 pages with 21 supplement "zoom" charts of galaxy clusters and densly populated areas, and indications of over 500 best objects (Messier, Caldwell, Herschel 400, SAC's best).
I designed this atlas with A3 page size in mind, however you may find it usable on A4 as well. In terms of scale and amount of detail - "DeepSky Hunter" falls between Sky Atlas 2000 and Uranometria 2000.
- Michael Vlasov

Here you can see a comparison with other atlases.

Note
- Print back to back on light 200gram carton (A3).
- It is searchable in Adobe Pdf Reader on your computer.  (Search the constellation or the NGC, etc.)
(Hannes Pieterse)