In this issue of SpaceTides

Dear SpaceTides subscribers

I had an interesting question recently regarding the value of astronomy and spaceflight to society. Why do we spend billions and billions on astronomical research and the building of spacecraft for planetary exploration? Shouldn't we rather use that money for immediate problems facing communities? Some people oppose such modern and sophisticated endeavours and ask whether it has any impact on our daily lives. Well, I can think of numerous reasons why we should INCREASE spending on astronomy and spaceflight! In the coming weeks I'll send out a special report on why astronomy and spaceflight should be encouraged and why it does have an effect on the average man on the street.

Please see the advert in section 11. On Saturday 22 April 2006, ASSA Bloemfontein will be hosting a beginner's day in practical astronomy.

I added a new section to the e-zine called "Photo Sense" - a specially selected picture for each issue. If you have a photo you took that you think can appear in SpaceTides, please send it in!

Gerrit Penning
Editor

Total subscribers as at 13 April 2006: 447 (+20 from previous issue #40)

1. Spaceflight news from around the world

Venus atmosphere the target of ESA space probe

The planet Venus has welcomed a visitor to its orbit on 11 April 2006, in the form of the European Space Agency's "Venus Express" satellite. It is now the only active, operational satellite orbiting Venus.

The planet's surface was mapped by the very successful Magellan spacecraft in the 1990's. From previous research, scientists discovered that Venus is enshrouded in a thick atmosphere. Due to extreme temperatures and pressure created by the atmosphere, a greenhouse effect of tremendous proportions is generated.

Venus Express is tasked with a detailed study of the atmosphere, using sophisticated sensors to solve the mysteries of the past. "It will also be the first Venus orbiter to conduct optical observations of the surface through 'visibility windows' discovered in the infrared spectrum".

ESA article: http://www.esa.int/esaCP/SEM2GQNFGLE_index_0.html
Image at left: artist impression of the Venus Express. Credit: ESA.

Expedition 13 the new crew on the ISS - April 2006

The Soyuz spacecraft carrying the 13th International Space Station (ISS) crew, Commander Pavel Vinogradov and NASA Science Officer Jeffrey Williams, arrived at the ISS on Friday, 31 March 2006.

With them was Marcos Pontes, the first Brazilian astronaut to go into space. He spent 8 days on board the station before returning to Earth with the Expedition 12 crew on 8 April.

More at: http://www.nasa.gov/mission_pages/station/main/index.html

Image at right: The Russian Soyuz spacecraft can be seen in the centre, carrying Expedition 13 just moments after docking to the space station.
Credit: NASA TV

2. Astronomy news from around the world

Debris field found around pulsar - released April 2006

NASA's Spitzer Space Telescope found evidence that a potential planet-forming disk exists around a pulsar. Pulsars are a class of supernova remnants, called neutron stars, which are incredibly dense. A neutron star can form when a massive star heavier than 1.4 times that of the Sun explodes. They consist of atomic matter (neutrons) squeezed into bodies only 10 to 20 km wide. A teaspoon full of neutron star matter can weigh more than 2 billion tons!

The pulsar observed by Spitzer's infra-red sensors was one such massive star that exploded, throwing off huge amounts of matter into space. A disk formed around the neutron star and the debris in this disk might ultimately stick together to form new planets.  Radiation from the pulsar however, would be so intense that the poor planets will probably be some of the most inhospitable planets in the Universe.

Left: artist impression of debris disk around a pulsar.  Credit: NASA/JPL
http://www.spitzer.caltech.edu/Media/releases/ssc2006-10/release.shtml

3. Interesting Space Facts

Naming of the stars: only the International Astronomical Union (IAU) may attach names to stars and other solar or deep sky bodies.  Any name that you attach to a star either personally or commercially will not be recognized by the scientific community at all. If a business offers you star naming services, there won't be any legal "copyright" on the name.  More at http://www.iau.org/BUYING_STAR_NAMES.244.0.html

The lowest temperature that can be theoretically attained (where the kinetic energy of atoms and molecules becomes minimal) is referred to as "Absolute Zero". It equals zero Kelvin or -273.15 degrees Celcius (-459.67 Fahrenheit). Although absolute zero is not achievable in practice, you may find areas in outer space approaching this limit. http://en.wikipedia.org/wiki/Absolute_zero

A Bushman myth explains the monthly phases of the Moon: the Moon was once a man who incurred the anger of the Sun. The Sun then attacked the Moon with his bright shine, slowly cutting up the Moon until only a small sliver remained. The Moon begged the Sun to at least spare this small piece for his children. The Sun agreed, but the Moon began to grow again. Once back to its original size, the process repeated itself. From the 2006 Sky Guide Africa South, page 57.

4. Space Questions

Can the Hubble Space Telescope take pictures of the Earth?

No. Hubble is travelling at a tremendous speed as it orbits the Earth (about 27 000 km/h). It orbits at an altitude of about 600 km. Hubble's pointing system is designed to target and track objects in the distance, much further away from Earth. It won't be able to track an object on the Earth, as the object will make streaks on the picture. The picture at left shows the Hubble above Earth, while in orbit. (credit: NASA)

From: http://hubblesite.org/reference_desk/faq/answer.php.cat=topten&id=78

The Hoba meteorite near Grootfontein in Namibia - the world's largest known meteorite. Image obtained from www.namibweb.com/hoba.htm.

Information at right from: http://epswww.unm.edu/iom/howto.htm

How do I tell the difference between a meteorite and an ordinary Earth rock?
If you are not an expert, it will be difficult to ascertain whether a rock you picked up is a meteorite from space. Here are a few characteristics of space rocks to keep in mind though:
- Metal: most meteors contain some iron metal, shining visible on a broken surface
- Density: Many meteorites are extremely dense and weigh more than similarly-sized rocks found on Earth
- Magnetism: meteorites tend to easily attract a magnet due to metal content
- Chondrules: most meteorites contain small balls of stony material called chondrules about a millimeter across.
- Fusion crust: because the meteor burns as it falls through the atmosphere, a thin layer on the surface melts, creating a black or brown colouring.
- Regmaglypts: it may happen that thumb-print patterns (regmaglypts) develop on the surface of the meteor as it falls through the atmosphere.

Remember that in South Africa, any meteorite falling within the country's boundaries belongs to the government, immediately. Private possession of or trade in meteorites is illegal - it should be handed over to your nearest science institute, University or the authorities!

What can I do to prevent myself from being abducted by angry-looking pink aliens resembling my favourite Hollywood actor? I'm having problems sleeping at night. And I'm hearing funny noises in the roof.

Though it might not prevent it, consider taking out UFO abduction insurance! If you do get abducted and something less-than-favourable happens to you, you might just get compensated for the damage. Just type "alien abduction insurance" into Google and go to any insurer of your choice... Also, check the inside of your roof. It might be rats or even unemployed circus clowns frolicking around. It's a growing concern.

5. Sky Observation Log

Descriptions for mid April 2006 around 20h00 from South Africa .

Planets visible
Mercury is in the constellation of the Fish (Pisces), being a morning object visible just before sunrise. It moves into Cetus from the 21st of April.
Venus shines bright in the morning hours before sunrise and is located in Aquarius.
Earth is currently orbiting an average yellow coloured star not far from Alpha Centauri. The planet will clearly appear blue and white if you come within a few hundred thousand kilometers.  Just beware the space debris orbiting around it please.
Mars is an evening object and has moved into Gemini in the north-west. It is visible with its typical reddish shine. Binocular users: watch as Mars approach the open cluster M35 in Gemini...
Jupiter is an evening object in the east. It rises earlier each evening (currently around 19h00), still located in Libra. A pleasure to look at through a telescope.
Saturn is still lying close to the Beehive open cluster (M44) in the north, in the constellation of Cancer (the Crab) in the evenings.

Constellations and stars
For those who still need to do observations in the summer constellations of Gemini, Canis Major and Orion - catch them while their still visible as they're busy setting...
The galaxy-rich constellation of Leo is your telescope's perfect target for an evening of galaxy hunting. If you're not accustomed to galaxy observations, start out with the Messier objects first. Virgo, also a treasure-trove of galaxies are busy rising and is becoming well-placed for observations.
Catch up on your autumn constellation knowledge while the temperature is still acceptable. Corvus the Crow and Crater the Cup are easy targets for beginners. If you're up to a challenge, try seeing Hydra, the Sea Serpent, in full view!
It's the best time of the year for southern sky observations, with the constellations of Puppis, Vela and Carina as well as Crux and Centaurus perfectly situated for deep sky observations. Make use of the opportunity!

Other events
Full moon on 13 April 2006. New moon on 27 April 2006.

6. Amateur Astronomers' Corner

A computer rendered image showing the major light sources on Earth. South Africa's major hubs are evident on the image.  Visit the
International Dark-Sky Association's website: www.darksky.org - proper light fixtures, PowerPoint presentations, outdoor regulations and more.

Light Pollution - the amateur's role

Although it is everybody's responsibility, the amateur astronomer can play an important role in reducing light pollution through public awareness.

If you belong to an astronomy club, attempt building such awareness into your public presentations and materials. You can even host evenings around the concept of dark skies, in very creative ways. Switch on all the outdoor lights and show visitors the effect when  switching them off. See how they understand!  A special emergency session after it was noted that the Milky Way has disappeared can also have an impact...

If you are associated with an observatory, invite people living nearby for a free evening at the observatory.  Register with a dark sky association.

7. Astronomy & Science in Africa

Website of the WGSSA:
http://www.saao.ac.za/~wgssa/index.php

The Working Group on Space Sciences in Africa

From the WGSSA website:
"The Working Group seeks to promote the development of the space sciences in Africa by initiating and coordinating various capacity-building programmes throughout the region. These programmes fall into a broad spectrum ranging from the promotion of basic scientific literacy in the space sciences to the support of international research projects".

8. Astronomy Events in the City of Bloemfontein

Explore Boyden Observatory:  www.assabfn.co.za/friendsofboyden/explore.htm
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 Dawie van Jaarsveldt at +27 +51 - 401 2561.

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. Please phone Braam for information on next meeting.

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.

22 April 2006: Beginner day in practical amateur astronomy, concentrating on night sky observations. See section 11 for more information.

9. Photo Sense

Image of an area on the outer edges of the Grand Canyon in the USA, approaching Las Vegas. The photo was taken from the air.  F/5.6, 8mm focus length, 1/125 sec exposure. Upward contrast adjustment to enhance colours. Photo taken 31 December 2005 by G. Penning.

10. Web links and Software

Links

The International Astronomical Union: http://www.iau.org/
 
APOD in the Classroom - Using Astronomy Picture of the Day as a teaching tool  - http://antwrp.gsfc.nasa.gov/apod/lib/apodclass.html
Affordable Astronomy Equipment Reviews - http://members.tripod.com/irwincur/
Cathcing the Light - Astrophotography - Information on the topic and a very nice selection of photos included...  http://www.astropix.com/
Astrobiology - Your on-line guide to the Living Universe: http://www.astrobiology.com/
NOAA Global Warming website - http://www.ncdc.noaa.gov/ol/climate/globalwarming.html

Other

New Discovery:  "Administratium" - http://philo.zm3.net/fun/Administratium.html
Strike one Lightning photos: http://strikeone.com.au/special/special.htm

Software

Google Earth: If you haven't downloaded Google Earth yet, you are missing out on one the most amazing things that free software has to offer you. Also contains commercial versions. Go to http://earth.google.com/

Stellarium:  An excellent astronomy program to learn the night sky from the comfort of your computer is Stellarium - it can also be used for open sky presentations by astronomy clubs and science centres, even planetariums.
Freeware: http://www.stellarium.org/

VESA Route Planner: South Africans might be interested to know that a similar program to America's MapQuest and Google Local is now available. It's called the "VESA Route Planner" where you can view city maps on your computer, insert your start and end locations and have the program work out a route for you, find distances between towns and cities etc.
Homepage:  http://www.veza.co.za/

11. Advertensie - Sterrekunde Beginnersdag: 22 April 2006

Beginnersdag in praktiese amateur sterrekunde - 22 April 2006

(Inquire if you would like the course to be partly in English).

Datum: Saterdag, 22 April 2006
Plek: Boyden Sterrewag, 25 km buite Bloemfontein na ooste, by Maselspoort vakansie-oord
Tyd: 14h00 vir 14h30 tot 22h00
Koste: R40 per persoon. Sluit in basiese sterkaarte en planisfeer.
Bring saam: Verkyker as jy het, ligte aandete, klein flitse, warm klere.
Bespreking: Bespreking is noodsaaklik. Kontak Gerrit Penning by mail@assabfn.co.za of skakel 084 429 9080.

"Waar en hoe begin ek met sterrekunde?"

Hierdie mini-kursus aangebied deur ASSA Bloemfontein sal 'n paar basiese aspekte van naglugwaarnemings aanspreek (uitken van konstellasies, sterre, planete). Daar word ook gekyk na hoe 'n mens 'n sterkaart en planisfeer effektief gebruik, die koordinaatstelsel, dieplugvoorwerpe vir die oog, verkyker en teleskoop en ook hoe om 'n verkyker aan te wend vir sterrekunde. 'n Paar multi-media aanbiedinge oor algemene sterrekunde sal sorg vir verskeidenheid. Ander onderwerpe waaraan geraak word sluit in komete en meteore, teleskope en sterrewagte, die maan, son en andere.

Kom geniet 'n rustige dag by Boyden en verbreed jou naglug kennis. Enige iemand welkom, al weet jy nie veel van sterrekunde nie.

 Krediet: Stellarium