Wednesday, May 31
A few things to look out for in the west after sunset this month.
As Tony Phillips of NASA and Spaceweather.com puts it.. "Something remarkable is about to happen in the evening sky. Three planets and a star cluster are converging for a close encounter you won't want to miss."
Sunday, May 28
Arrive 20 min early on Tuesday and IF it is clear and IF the sun is high enough to be seen from near the hall, you could be treated to an unusual view of the sun. The picture is a taster but the real thing is rather stunning. Visit my website for more information on how this is done.
Saturday, May 27
Next Tuesday (30th May) is our next CAS meeting, so what have we got planned ?
Well as well as the usual news round-up Chris will be giving us an update on extrasolar planets, how we find them, what they are like etc. Following that Dennis will be talking us through his latest project, building a simple refractor telescope.
We'll also be taking care of a bit of housekeeping business by holding our Annual General Meeting. We need to vote on a constitution, committee officers etc. Hopefully that shouldn't take too long. If anyone would like to get involved in the committee let me know. See you all there.
Thursday, May 18
It was only a matter for time....
The collaboration between amateurs and professionals hunting exoplanets by the transit technique has finally paid off.
The professionals spotted a likely candidate and the amateurs confirmed the small drop of light caused by the planet (named XO-1b) passing in front of the sun like star.
Read the full story at the Hubble website newsdesk here
Tuesday, May 16
The team believe that Triton was caputured by Neptune during a three body encounter in the early history of the solar system. They think Triton was actualy part of a binary planet system, very similar to the current Pluto-Charon system, which had a close encounter with Neptune. It's worth remembering that Triton is 40% bigger than Pluto, and has active geysers on it's surface.
More technical details at Planetary Society's Blog.
Image Credit: NASA - Triton
News has been pretty thin on the ground for the last week or so. I hope some of you have managed to find the Comet 73P/Schwassman-Wachmann 3 over the last few days, although the weather has not been ideal.
Sunday, May 14
All elements operate from the same type of interface, which is very similar to Google Earth. You use the mouse to scroll around a spherical projection, and as you pan and zoom; you stream more detailed imagery from the internet.
For the Earth, it doesn’t have much of the street level detail you find with Google Earth (unless you’re a yank..!); but provides more in the way of topographical; geographical and scientific detail. The main advantage for me is that the wider shots are not cluttered with the high resolution detail overlays you get with Google Earth, so macro features are easier to see. You only stream these overlays as you zoom in. You also get a lot more choice as to the source data used (several Landsat and USGS satellites, and many others).
The volume of data being streamed is significantly more than with Google Earth, and as a consequence, you will need a fast broadband connection, and even then, it is slower. It is also at least as demanding graphically as Google Earth, so you will need a Cray Supercomputer.
The Mars and Moon modules work in exactly the same way as the Earth, with several data sources available. Both are excellent.
The Sloan Digital Sky Survey (SDSS), provides a spherical projection of the night sky; but only with the current SDSS coverage (so there’s a lot of blank areas). It’s great if you know your way around the sky; but doesn’t provide any labels. Your best bet is to use along side your standard planetarium software to aid navigation. Again, it is streaming a vast amount of data from the internet, so can be slow; but some of the results are well worth the wait.
The help menu for all modules also links to extensive on-line documentation; add-ins and forums.
Earth (using NASA Bluemarble imagery) Jan 2004 showing snow cover.
Friday, May 5
Image: NASA / Cassini
These radar images from the most recent flyby show surface features in the Xanadu region of Titan's surface.
Image: NASA / Cassini
The image above is of Shikoku Facula, a region that is bright in both radar and visible wavelengths. The feature appears as an 'island' in the dark Shangri-La region next to Xanada, and was dubbed 'Great Britain' because of its appearance in visible light at lower resolutions.
For a labelled view of the whole region click here.
Analysis of radar data has lead scientists to conclude that the dark regions once thought to be liquid oceans, are in fact composed of large sand dunes. See this article.
Wednesday, May 3
Monday, May 1
Thanks to Stuart for pointing this one out. Cassini has sent back another stunning image from Saturn. This one includes a section of the rings, with tiny moon Epimetheus (Diameter 115km) in the foreground and huge moon Titan (Diameter 5150km) behind the rings. The timing of these shots is impressive, given that Cassini is traveling at about 20km/h relative to Saturn, and Saturn is about 80 light minutes away from the Earth.
This image is a 'raw' image from the Cassini website, meaning it is as sent back from Cassini without any additional processing. So we may see an 'enhanced' version over the next few weeks.
Some interesting information on the Planetary Society Blog on the amount of data returned by Cassini to date. Cassini has just completed (yesterday) a flyby of Titan where the radar imaging equipment was used to survey the bright area on the surface know as Xanadu.
You can observe Titan with a fairly modest telescope, see this Sky and Telescope article for details.