Psychogeeks

I recently had the pleasure of attending a friend’s birthday party (Thanks Kate) with another friend (Dane). During conversation Dane asked about the meaning of the images on the front of his tee-shirt (right). Dane had figured that parts of the imagery were related to the zodiac and the months of the year. What wasn’t clear was whether the device in the middle of the circle was just a meaningless ornament, or something of astronomical interest.

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It is 20 April in the Canberra region. The autumn evening temperature is rapidly dropping toward what will be the lowest temperature of April: 3.6 deg. Celsius. Despite the conditions, five amateur astronomers are setting up across the region to watch the rather nondescript star HIP 59807 in the constellation Corvus for a quarter hour or so. They hope to catch an event a few seconds long. What is this event and why would anyone do this?

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One of my favourite time wasters is a small game called Kobo Deluxe. Kobo Deluxe is a fast-paced multi-way scrolling shoot-em-up. The game is an update on the original XKobo by Akira Higuchi and bears a passing resemblance to Bosconian. The game’s simplicity only serves to heighten its very addictive nature. It runs on UNIX-like operating systems and Windows so I can get a fix any time.

After recent upgrades to my home PC I discovered, to my great dismay, that Kobo now ran with terrible sound glitches and crackling on Windows, and not at all under Linux. The new sound system is a Realtek ALC883 (Intel high definition audio) and most everything else worked properly. Fiddling with the range of sound options in the game did nothing to alleviate the problem.

The game uses the SDL for its sound, and ships with SDL libraries. I started looking at upgrading the SDL library and found the shipped version were a few dot-releases old. The following steps update the SDL libraries in Kobo Deluxe on Windows:

1. Download the latest Windows SDL library binaries
2. Download the latest Windows SDL-Image library binaries
3. Unpack both archives
4. Copy all the unpacked DLL files into the Kobo Deluxe game directory, overwriting existing files.
5. Play!

This seemed to fix the problem on Windows.

On the Linux side of things, the game hangs trying to start with audio enabled. This problem may also be related to using a dual core processor. I’ll keep you posted with any progress.

The image above shows detail of the interacting portion of two colliding galaxies: NGC 4038 and NGC 4039, otherwise known as the Antenna Galaxies. This is an extract of an image taken by the Hubble Space Telescope.

The Antenna Galaxies get their name from their appearance in optical images taken from the ground. Visible on the left of image to the right (click for larger version) are two streams of stars that have been thrown out by gravitational interaction between the galaxies. From studies of the dynamics of the stars in these galaxies we believe that they started to interact something like 200-300 million years ago. The tails are the result of this initial interaction. The remnants of the original galaxy core regions are the two bright orange hued regions in the right hand pane of this image.

Despite the typical galaxy containing a billion or more stars it is very unlikely that the stars themselves would collide with each other: the average distance between stars being too large. The two galaxies interact with each other through gravitation resulting in disruption to established stellar motions. In the dense core regions of typical galaxies are large amounts of free gas and dust which will merge in the even of collision. Large brown lanes of dust, obscuring the light from the stars behind, are clearly visible around the image centre and running down the arm to the bottom of the image. In regions where the gas and dust reach high enough density we would expect to see a local peak in star formation. In the image to the left (click for large version) these star formation regions are numerous and appear as bluish clusters of hot, new stars surrounded by ionised hydrogen gas (pink glow).

I chose this image because it demonstrates the dynamics of galactic interaction and of star formation. It also gives a glimpse of the fate of our own galaxy should it ultimately it collide with the relatively nearby Andromeda Galaxy in a few billion years or so.

Images courtesy of NASA, Hubble Heritage and the STScI
News Release Number: STScI-1997-34
News Release Number: STScI-2006-46

The image above shows the Valles Marineris (Mariner Valley) canyon system. At over 3000 kilometres in length, up to 8 kilometres deep, and Valles Marineris absolutely dwarfs Earth’s Grand Canyon. In contrast, the Grand Canyon is a mere 446 kilometres long and 1 kilometre deep.

The two Viking Mars missions each consisted of a lander and an orbiter. Using 102 images taken by the orbiters Jody Swann, Tammy Becker, and Alfred McEwen used the PICS(Planetary Image Cartography System) image processing system developed at the U.S. Geological Survey to produce this mosaic image. The mosaic images were reprojected and stitched together to give the effect of a global view from 2500 km altitude. The entire Valles Marineris system is visible. Also visible are three volcanoes, dark red spots on the west (left) edge, in the Tharsis region. These volcanoes also dwarf their terrestrial counterparts, rising about 25 kilometres above their surrounds.

You can take a video tour of the canyons at Google Video here. Other versions for download can be had here. Google Mars also provides views here.

Image courtesy NSDDC and NASA
NSDDC Mars Photos