In this issue of SpaceTides

1. Spaceflight news from around the world

Image credt: NASA/JPL
Image credit: NASA/JPL/UMD Artwork by Pat Rawlings

The Deep Impact mission to Comet Tempel 1
Adapted from the JPL Deep Impact Fact sheet: http://deepimpact.jpl.nasa.gov/mission/index.html

On July 4, NASA's Deep Impact satellite will launch a smaller impactor-craft which will "collide" with comet Temple 1. Comets (large rocks orbiting the Sun) are "time capsules" of the solar system: they contain age-old ice particles, gas and dust which can tell us more about the formation of the solar system some 4.5 billion years ago.  Deep Impact will be the first mission to probe beneath the surface of a comet and study its interior.

The crater that will be produced after impact will vary between the size of a house and a rugby field, 2 to 14 stories deep. The expectation is that ice and dust will be ejected into space during impact, revealing "fresh" material beneath. Cameras and spectrometers on the fly-by satellite and instruments on Earth will closely monitor the complete collision procedure.  Data accumulated from these different sources might help us to gain a better understanding of the formation of the solar system and the implications that comet collisions had with Earth in the past.

Videos and animations: http://deepimpact.jpl.nasa.gov/gallery/animation.html

2. Astronomy news from around the world

Image credit: NASA, ESA, HEIC, (STScI/AURA)

Spectacular Hubble image of supernova remnant N 63A
07-06-2005, larger image, with more info:  http://hubblesite.org/newscenter/newsdesk/archive/releases/2005/15/

The Hubble Space Telescope captured this stunning picture of a "violent and chaotic-looking mass of gas and dust" of a nearby supernova remnant. It was named N 63A and represents the remains of a massive star that exploded and spewed its gaseous layers out into space.

The gas cloud is situated in the Large Magellanic Cloud - a satellite galaxy of our own Milky Way galaxy, 160 000 light years away. Scientists estimate that the exploded star was 50 times more massive than our own star, the Sun. Radio emission images of N 63A show a much more expanded bubble that totally encompasses the optical emission seen by Hubble here.

Image credit:  NASA/JPL-Caltech/O. Krause (Steward Observatory)

Spitzer Space Telescope observes echo of neutron star outburst
University of Arizona News Release, June 9, 2005.
More info and larger image: http://www.jpl.nasa.gov/news/news.cfm?release=2005-099

The Spitzer telescope observed a huge light echo in infrared, produced by a fitful dead star. This finding indicates that Cassiopeia A, the remnant of a star that died in a supernova explosion 325 years ago, is not resting peacefully. It is presumed that the star most likely shot out at least one burst of energy as recently as 50 years ago.
Scientists thought that the star's remains were simply fading away, but this image showed that it is still undergoing "death throes".  What you see here is clumps of the surrounding dust created by the blast, heated by light waves moving outward and causing the dust to glow in infrared.

3. Interesting Space Facts

- NASA's Chandra X-ray Observatory, which was launched in 1999, is the most sophisticated X-ray observatory built to date. The craft orbits around 130 000 km above Earth (about a third of the distance to the moon). The light from some of the objects Chandra can observe has been traveling through space for over 14 billion years. Chandra homepage (with e-mail news subscription service): http://chandra.harvard.edu/

- If the Earth was the size of the ball of a ball-point pen (not even a millimeter in diameter), the Sun would almost  be the size of a golf ball and will have to be placed 5 meters away for the distance scale to be more accurate. Nearly 110 Earths can fit into the diameter of the Sun. More scale facts: http://www.lpi.usra.edu/education/explore/solar_system/planet_sizes.shtml

- Humans have only been physically as far as the moon. Mankind has however, sent many robotic satellites,
landers or rovers to all the other solar system planets except Pluto. Some has only flew by the planets, others were put into orbit around them.  Currently doing active planetary research work:  3 satellites orbiting Mars, two rovers traversing Mars, 1 satellite orbiting Saturn and its moons and hundreds of satellites around that very special  of all planets, Earth! Other current missions, e.g. Moon, Sun and more:
http://www.ccastronomy.org/space_missions_current.htm#Cluster%202

4. Space Questions

Why do meteors ("shooting stars") emit such a huge amount of energy when entering the atmosphere, even though...
...these meteoroids are usually nothing else and nothing bigger than a grain of sand?

We've all seen those most beautiful of light streaks in the night sky, popularly known as "shooting stars". On a daily basis, as many as 4 billion meteors fall to Earth weighing in total several tons. But why so bright? The answer: their enormous speed - meteors travel at about 60 to 70 km a SECOND! (The Shuttle orbits Earth at 8 km/s). "Ram pressure" is also at work. Air is compressed by the meteor in front of it, which heats up the air. The rock/grain of sand is heated in turn and start to "burn up".

The far side of the moon Credit: NASA / Apollo 16.

Why does the same side of the Moon always faces Earth?

Each time you look at the Moon, whether in the day or at night, you will always see the same side. Ever wondered why? This is because of the way in which the Moon orbits the Earth. Where the Earth makes one rotation every 24 hours around its own axis, it takes the moon 28 days to make one orbit around its own axis. This is also "co-incidentally" the time that the moon takes to make one orbit around the Earth. Ask a friend to play the Earth. You are the Moon: walk around the person while facing him/her the whole time. After you made "one orbit" around the person, you would also have spun 360 degrees; as if you were stationary while making the spin!

5. Sky Observation Log

The Southern Night Sky

South Africans should feel very fortunate to have at their disposal such a magnificent view of the southern night sky. Especially in Autumn and Winter, the constellations in the southern region are bright and prominent, with a treasure trove of deep sky objects (for binoculars and telescopes). The most beautiful region south is probably the Centaurus-Crux area, and more to the west no doubt the constellations of Argo: Carina, Vela, Puppis & Pyxis.
More information on how to begin observing the night sky:
www.assabfn.co.za/deepsky.htm

6. Astronomy News in Southern Africa

Credit: HESS

International H.E.S.S. project in Namibia
Information obtained from: www.unam.na/research/hess/

The newly installed telescope, first of a series of many such instruments, will be used to study space phenomena such as black holes, quasars, pulsars, supernova remnants, exotic heavy particles left over from the creation of the universe, etc. The site for the project is located in the Khomas Highland, about 103 km West South West of Windhoek on the farm Goelschau. H.E.S.S. stands for High Energy Stereoscopic System. This acronym also honours the famous Austrian Physicist, Victor F. Hess who discovered cosmic radiation in 1911/2. The project is a major boost for Southern Africa's astronomical basis, adding to its international reputation as an excellent observing region.

7. Astronomy Events in the City of Bloemfontein

The different astronomy organizations in the City, working hand-in-hand to expose people to the interesting
world of astronomy and spaceflight, can be reached at the following addresses:

Explore Boyden Observatory:  www.assabfn.co.za/friendsofboyden/explore.htm
One of the most publicly accessible observatories of its kind in the Southern Hemisphere, also housing SA's third
largest telescope.
- Kunstefees lesing "En daar was lig", 13 Julie 2005 (CR Swart Ouditorium, UV kampus, 18:00) en 15 Julie 2005
(Boyden Sterrewag, 18:30 vir 19:00). Kaartjiebespreking verpligtend: www.volksbladfees.co.za

The Friends of Boyden:  www.assabfn.co.za/friendsofboyden
A public interest group for Boyden Observatory and for people interested in joining the astronomy community of
Bloemfontein, but not make astronomy their "full-time" hobby.
- Go to the Friends' website above for the calendar of 2005.

ASSA Bloemfontein Centre:  www.assabfn.co.za
Affiliated with the Astronomical Society of Southern Africa, the Bloemfontein Centre of ASSA is an active organization of amateur astronomers meeting on a regular basis to discuss and practise astronomy.
- Send an e-mail to mail@assabfn.co.za for more information or visit the website.

Onthou ook om Boyden Sterrewag se gereelde sterrekunde berigte in die "Ons Stad" plaaslike koerant te lees.
Dit bevat ook meer inligting rondom Boyden besoektye.

8. Web links & Net nodes

- e-Books which can be downloaded for free: www.gutenberg.org. These books are mostly older literary works that are in the public domain in the United States.

- Ever heard of the GO Open Source project? It is sponsored by such organizations as The Shuttleworth Foundation and the CSIR and can be reached at www.go-opensource.org. It encourages distribution of their excellent low-cost  or free software.

- Coding theory used in cell phone technology and even deep-space probes are to be used by HP as a new way of designing nanoelectronic circuits, potentially decreasing manufacturing costs extensively: Information week website.

- Some say space is the final frontier, but in my opinion it is the human brain!  "Caring for your brain" is probably just as important than caring for your body overall. The New Scientist indicates 11 steps to a better brain: www.newscientist.com/channel/being-human/mg18625011.900

- Anyone got a Ph.D in robotics lately? Robots are progressively being displaced out of sci-fi books and into reality. Comprehensive info: www.learnaboutrobots.com

- For those few spare minutes you don't know what constructive way you can help society in, try a few puzzles!
www.puzzles.com