In this issue of SpaceTides

Dear SpaceTides subscribers

The rain and clouds (though very welcome!) in South Africa's interior don't allow much night sky observations at the moment, but we have some drier months ahead, which is also a fine time for deep sky objects and constellations. Especially in April and May observers in the southern hemisphere have the spectacular Carina/Vela/Puppis area of the sky at their disposal.

Private space enterprise suffered a major setback recently when the SpaceX "Falcon 1" rocket, carrying a weather satellite, failed during launch. Governmental space programs, although they have huge budgets, can be very lethargic and ineffective. In many enthusiasts' opinion, private space enterprise is the way of future space transport - they are not as restricted as government programs when it comes to taking risks and seems to be quite open for new ideas and innovation.

Have you ever thought of the value of astronomical teaching for children? Keep in mind that astronomy tends to broaden a child's perspective very much. It makes them come in contact with the splendour and mysteries of nature and teaches them an appreciation for the natural environment from an early age.

Enjou the issue!

Gerrit Penning
Editor

Total subscribers as at 27 March 2006: 427 (+19 from previous issue #39)

1. Spaceflight news from around the world

Falcon 1's maiden rocket launch unsuccessful

SpaceX, founded by Elon Musk (born and schooled in South Africa), suffered a setback when their Falcon 1 rocket failed during its maiden launch.

The rocket burned up shortly after lift-off and fell in the Pacific ocean. Although all vehicle systems performed without error, a fuel leak of yet unknown origin caused a fire which shut of the rocket's main engine.

Elon Musk made his fortune as co-founder of PayPal and from the earlier Zip2 software application. He formed SpaceX with the purpose of immensely reducing the cost of rocket launches to Earth's orbit and beyond. The Falcon 1 rocket is three times less expensive than rockets of similar power. Larger Falcons are planned for the future.

Extracts from: http://www.spaceflightnow.com/falcon/f1/060324failure.html

SpaceX website: http://www.spacex.com/

Left: Falcon 1 on fire during launch. Credit: SpaceX

Other spaceflight news:

Mars Reconnaissance Orbiter sends back first test images (March 2006) - JPL News Release
The MRO, one of 4 satellites orbiting Mars (and the most recent arrival), sent back superb images of the planet's surface. These images serve as tests for future research. The images can be accessed at: http://www.nasa.gov/mission_pages/MRO/main/index.html

More information at: http://www.jpl.nasa.gov/news/news.cfm?release=2006-042

2. Astronomy news from around the world

An illustration showing quasar activity in the centre of a galaxy. Galactic superwinds are expelling gas away from the galaxy's centre at tremendous speeds. Credit: NASA.

A Quasar in the Distance...

Many galaxies appear to have black holes at their centres. Sometimes these black holes become very active by sucking up large quantities of materials (like gas) and emitting huge amounts of energy in the X-ray spectrum. Supermassive black holes gone berserk. And quasars result...

What is a "quasar"? A quasar is a source of electromagnetic energy so immense that one quasar can dwarf the energy output of all the stars in its galaxy. An overheating engine in space!  Quasars seem to be powered by the accretion of material (like gasses) onto supermassive black holes in the centres of very distant galaxies.  As gasses "fall into" the black hole, it ignites and create a "quasar" (energy source) of immense proportions.

Quasars are also referred to as luminous versions belonging to a type of "active galaxies".  Much research still needs to be done on these interesting objects.

Researchers using the Chandra X-Ray satellite detected two such quasars recently, during the ignition phase of the gasses falling onto the black hole. Eventually the gasses will be blown away from the centre of the galaxy by winds created during explosions and "things will turn back to normal", as the black hole doesn't have enough food for further meals...

Read article at: http://www.universetoday.com/am/publish/4C37_43_quasar.html?2332006
More on what quasars are: http://en.wikipedia.org/wiki/Quasar

3. Interesting Space Facts

- Earth's atmosphere consists of 21% oxygen and 78% nitrogen. The remaining 1% consists of other gasses.

- Once your car indicate that it has travelled 380 000 km in its life, you have travelled the total distance between the Earth and the  Moon!

- The fastest spacecraft built by man reached speeds of 252,800 km/h - the NASA-German Helios 1 & 2 - during their orbits of the Sun (source). This translates to about 70.2 km per second. Compare this speed to the speed of light which is 300,000 km per second!

- Nine of the top 10 warmest years globally have occurred since 1995. Various studies indicate that the high average temperatures in the northern hemisphere over the last decade are unprecedented over the past 2,000 years.
From: http://www.ucsusa.org/global_warming/science/heat-wave-2005-and-Global-Warming.html

4. Space Questions

Space debris (Delta 2 rocket parts) that fell in South Africa in 2000, 3 objects spaced over 100 km. Photo from the NASA Orbital Debris Program Office website. Watch your head!

How many man-made satellites are in orbit around Earth?

Only about 400 to 500 active satellites are currently orbiting Earth. An exact figure may be difficult to ascertain, especially if you include spy satellites! Many hundreds of inactive (dead) satellites still orbit the Earth.

The real problem lies with space debris: useless man-made objects orbiting Earth. According to the NASA Orbital Debris Program Office website there are approximately 11,000 objects larger than 10 cm.  The number of objects between 1 and 10 cm in diameter is estimated to be greater than 100,000. The number of particles smaller than 1 cm may exceed tens of millions. 

Pieces of space debris pose a risk to satellites as they can travel at 28 000 km/h. If they hit another object, major damaged can be caused.

More information:
http://www.orbitaldebris.jsc.nasa.gov/faqs.html#3
General info:
Windows to the Universe Space Debris update

Shuttle photo of Earth's atmosphere from Space. Credit: NASA/JSC.

What formed the oxygen in the Earth's atmosphere?

The so-called "Biological Era" of Earth's natural history was marked by a reduction in the carbon dioxide in the atmosphere and an increase in oxygen - the latter being the most important gas for life on Earth. (Simplified) - hundreds of millions of years ago, small one celled plant-like organisms in the sea, protected by the water from the dangerous radiation of the Sun, started undergoing photosynthesis - the process whereby solar energy is used by plants to produce certain organic molecules and oxygen.  A protective ozone layer (a form of oxygen) formed in the initial phases followed by "ordinary" oxygen in the atmosphere. Primitive life in the sea thus generated the oxygen in the atmosphere, paving the way for life on land.

More info at: http://vortex.plymouth.edu/atmosphere/evolve.html

Will the Earth be destroyed and all life exterminated on 1 April 2006 by a huge purple asteroid resembling the figure of a well known dinosaur still alive today?

No. Probably not. Most unlikely.

5. Sky Observation Log

Descriptions for end-March 2006 around 20h00 from South Africa.

The naked eye planets
Mercury: In the constellation of Aquarius in the morning
Venus: In Capricornus in the morning - very bright
Earth: Somewhere between the orbits of Venus and Mars
Mars: In the constellation of Taurus, visible from sunset until about 22h00 when it sets
Jupiter: Currently in Libra in the evenings, rising 20h15
Saturn: Currently in Cancer to the north, visible throughout the evening from sunset

Constellations and stars
The old constellation of Argo Navis (Jason's ship) - now consisting of Carina, Vela, Puppis and Pyxis are ideally located in the evening sky for observations. They contain a wealth of deep sky objects and bright stars. Now is the time - be sure to take advantage.
Leo in the north is filling the evening sky with its bright stars.
Hydra, Corvus and Crater are slowly taking over the mid-sky above our heads.

Other events
New moon on 29 March 2006. Full moon on 13 April 2006.

6. Amateur Astronomers' Corner

This image of Jupiter, taken by Mauritz Geyser (ASSA Pretoria) in 2005 was stacked from 810 frames, using a QuickCam Pro 4000 webcam with 2x barlow lens through an 8 inch telescope. Even though poor sky conditions existed, the shadow of the moon Europa is clearly visible as well as the Great Red Spot (centre right).

Stacking astro-photos to reduce image noise

Many digital camera owners are well aware that digital images can contain a lot of "noise" - stray pixels on the photo that weren't meant to be there in the first place. Especially in darker photos noise can accumulate to irritating levels. The chips of digital cameras are quite sensitive to light. When you take photos of the night sky, either with or without the aid of optical instruments, stray light (from e.g. the city) can enter the camera and cause unwanted pixels.

There's a solution for lowering noise on digital images. Most amateurs are knowledgeable about the "image stacking" practice: using a software application to "stack" numerous photos taken in quick succession of one particular subject. Even photos taken with an ordinary low-budget digital camera can be stacked. Steadily point the camera (or webcam!) through the telescope (start with a bright object like Jupiter or Saturn), take a few photos one after the other as quickly as possible, transfer it to your computer, pull them into the stacking application and let the program work its magic.

According to "The New Amateur Astronomer" by Martin Mobberley, noise on a photo reduces with the square root of the number of images stacked: in theory a stack of 4 planetary images will have half the noise of a single image. 16 will have 4.

Stacking broadens your options when it comes to image processing. You can now play around more comfortably with exposure times. How many images to stack? That you will probably have to find out for yourself, for your particular expertise and equipment as well as your specific photographing conditions.

Image stacking software can be found at:
Registax: http://registax.astronomy.net/
Astrostack: http://www.astrostack.com/

7. Astronomy & Science in Southern Africa

etaCarina  - (Astrophotography)

etaCarina, maintained by Maurtiz Geyser (ASSA Pretoria), is a website specializing in astrophotography. Here you will find some of the best photos taken by South African astrophotographers. It includes numerous pictures of the planets, the moon, deep sky objects and related items.

Go to: http://www.etacarina.co.za/

Image at left: The Milky Way in the area of the tail of Scorpius. Credit: Mauritz Geyser.

8. Astronomy Events in the City of Bloemfontein

Boyden Observatory
One of the most publicly accessible observatories of its kind on the continent, also housing SA's third largest telescope.  To arrange group visits to the Observatory, phone Dr. Matie Hoffman at 051-401 2924 for more information, or send an e-mail to him at: HoffmaMJ.SCI@mail.uovs.ac.za

The Friends of Boyden:  www.assabfn.co.za/friendsofboyden

A public interest group for Boyden Observatory and for people interested in joining the astronomical community of  Bloemfontein, but not necessarily make astronomy their hobby. Contact Braam van Zyl at 051-436 7555 (h) or visit the website above for more information regarding the Friends. Anyone can become a member. R50 membership fee per year for a whole family. Members receive the latest information on astronomy events in Bloem, attend the Friends' presentations free of charge and receive the "Naghemel" quarterly newsletter compiled by ASSA Bloemfontein, by post. 

April's Friends meeting: a special evening for the Friends of Boyden on the controversial though very important subject of "Light Pollution" will be presented at Boyden Observatory. Please phone Braam for more information.

ASSA Bloemfontein Centre:  www.assabfn.co.za

Affiliated with the Astronomical Society of Southern Africa, the Bloemfontein Centre of ASSA is an active organisation of amateur astronomers meeting on a regular basis to discuss and practice astronomy as hobby. Activities include solar-, lunar-, deep sky- and comet & meteor observations, as well as historical research, telescope building, tours and away-weekends under dark skies. Send an e-mail to mail@assabfn.co.za or visit the website.

9. Web links

Night Sky Info:  http://www.nightskyinfo.com/
- maintained by Emil Neata in Romania, a website dedicated to observational astronomy with tips and resources on sky watching.

David Malin's Home Page:  http://www.ast.cam.ac.uk/AAO/images/general/malin.html
- more information on David Malin and links to his photos.

Celestia Space Simulation program: http://www.shatters.net/celestia/
- totally amazing what you can do in space from the comfort of your own computer... Download and see!

VisibleEarth: http://visibleearth.nasa.gov/
- stunning pictures of planet Earth

ASSA Historical Section: http://assa.saao.ac.za/html/39_historicalsection.html
- comprehensive website on the history of astronomy in South Africa

ESA Exercises in astronomy: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=35011
- for teachers to challenge learners on astronomical concepts

10. Advertisement - ScopeX 2006

ScopeX 2006 in Johannesburg

This year's ScopeX will be held on Saturday, 6 May 2006 at the Military History Museum in Johannesburg.  Each year's ScopeX is a very enjoyable event and no-doubt a learning experience for everyone attending. Amateur telescope makers show visitors their telescopes, presentations by well-known amateur and professional astronomers are given, astronomical merchandise is exhibited and much more. A must for anyone interested in amateur astronomy and especially telescope making. The world renowned photographic science-astronomer David Malin from Australia will be the keynote speaker!

Please visit http://www.assajhb.info/DNN/ for full information and forward this advertisement to persons you think will be interested.