Subscribe to the free SpaceTides e-zine by sending an e-mail to spacetides@assabfn.co.za
with the word "Subscribe" in the subject line if you are not already subscribed.

In this issue of SpaceTides

Hello SpaceTides Subscribers

The National ASSA astronomy symposium at Boyden Observatory in Bloemfontein is less than a month away. If you haven't completed your registration form yet, please do so as soon as possible... It is open to the public!  Please visit the website at http://www.assabfn.co.za/symposium2006.  Bloemfonteiners especially should not miss out on this rare opportunity. If you cannot attend the whole Symposium, there are options to attend only certain sessions. More info below.

Public astronomy events in Bloemfontein have come to a temporary halt, in preparation for the important Symposium mentioned above. Normal schedule will return after end of September. The next Boyden Observatory open evening is on 14 October 2006. More about this in the next SpaceTides!

Pluto is not a "full-out planet" anymore. After the decision by the IAU at their international assembly in August 2006, Pluto is now classified as a "dwarf planet". It did not meet the criteria of qualifying for a planet. Our solar system now has only 8 official planets. See heading 2 below for more info.

SpaceTides will in future appear once a month (as it has been doing the past few months).

Any questions or remarks about the SpaceTides service, please ask!

Regards,
Gerrit Penning, editor

Total subscribers as at 1 September 2006: 673 (+40 from previous issue #46)

Correction to previous issue (#46)
  - It seems the hoax hoaxed me! Please note that in the previous issue of SpaceTides, under the heading "Beware the Mars Hoax!", the figure "34 million km" should have read "34 million miles". This equates to 56 million km. What a weird correction to make to a hoax that was incorrect to start with in the first place! The correct data: "In August 2003, Mars came within 56 million kilometers of the Earth". Please sign my petition requesting the Americans to change over to the metric system...

1. Spaceflight news from around the world

The Atlantis crew gathers on the runway of the Shuttle Landing Facility in Florida Saturday after arriving in NASA T-38 jets. NASA.

Shuttle Atlantis readies for next ISS mission
Spaceflightnow.com news article, 3 Sep 2006.  Go to Link.

After delays, NASA has restarted the shuttle Atlantis' countdown for a Wednesday blastoff on a long-awaited mission to continue the space station's assembly.

Atlantis and its six-person crew will deliver a $372 million set of solar arrays to the International Space Station. 

The Boeing-designed payload features two new solar arrays and a massive rotary joint that will permit the giant panels to slowly turn like a giant waterwheel to track the sun as the station circles the globe once every 90 minutes.

SMART-1's impact photographed by the Canada-France-Hawaii Telescope / 2006. See GIF animation at SpaceWeather.com.

SMART-1 went crashing into the moon
From an ESA press release dated 3 Sep. 2006. Full article.

At 07h42 SA time, 3 September 2006, a small flash illuminated the surface of the Moon as the European Space Agency's SMART-1 spacecraft impacted onto the lunar soil, in the Lake of Excellence region. The planned impact concluded a successful mission that, in addition to testing innovative space technology, had been conducting a thorough scientific exploration of the Moon for about a year and a half.

The explosion was too faint for most backyard telescopes, but professional observatories did witness the impact, when the satellite collided with the moon at 7 200km/h.

2. Astronomy news from around the world

Comparative chart of Pluto and other solar system bodies. The recently discovered UB 313 was one of the Kuiperbelt objects which gave way to the planet definition controversy. Because a Kuiperbelt object (including Pluto) "hasn't cleared the neighbourhood of debris around its orbit", it cannot be called a planet. Some of them qualify for the term "dwarf planet".
Image credit: Max Planck Institute for Radio Astronomy

Pluto now known as a "Dwarf Planet"
Based on IAU news release of 24 Aug 2006. Full article.

In the past few years you frequently heard astronomers claiming they have "discovered the 10th planet". One after the other, discoveries of "planet nr. 10" came rolling in...

Pluto forms part of a huge asteroid belt somewhat behind the orbit of Neptune. Thousands and thousands of large space rocks orbit the sun just like the planets do. This area is called the "Kuiperbelt". It is something we did not learn in school and which was not standard in text books.

Astronomers have found over 1,000 Kuiperbelt objects since 1992 (Newsweek 4 Sept. 2006). Some of them are larger than Pluto and probably also round. Suddenly some structure was necessary to the whole definition of what a planet is!

At its General Assembly in August 2006, the governing astronomical body of the world (International Astronomical Union) came up with a definition of a "planet" and unfortunately Pluto did not meet the criteria. It does however, meet the definition of a "dwarf planet", together with a few other dwarfs already discovered.

It has now become more important than ever to teach children about the great Kuiperbelt and what lies beyond. It will help broaden our perspective of the scale of the solar system, which is much larger than we came to realize. Pluto will be seen as a symbol of our need to better understand the size and origins of our solar system.

Artist Bob Watson's concept of a 'polar binary' - the white dwarf star below sucking in the gas from the larger star.

New Press Release from the Southern African Large Telescope
Extracts from SALT press release dated 16 August 2006.  Read full article.

The Southern African Large Telescope (SALT) released its first public research results on 16 August 2006, giving new insight into an exotic pair of stars closely orbiting one another.

Researchers used a strength of the SALT design which is rare among large telescopes: the ability to take 'snapshots' of stars in very quick succession in order to study the rapidly changing properties of compact stars, especially as they pull in gas from their companions or surroundings.

The gravitational field of a compact star commonly pulls in gas from a companion star - the radiation (especially X-ray) emitted as this happens is one of the indirect ways scientists use to detect black holes. It is also the way that mass builds up on some compact stars until supernova explosions blow them apart, leading to 'Type Ia' supernovae recently used to show that the expansion of the universe is speeding up.

In a polar binary like the one SALT studied, the 'white dwarf' star also has a very strong magnetic field, which strongly influences how the hot gases from its relatively ordinary companion reach the white dwarf's surface.

3. Interesting Space Facts

Tribute to Clyde Tombaugh: the discoverer of Pluto

Clyde Tombaugh (1906 – 1997) was born in Illinois in the USA . As a child he became interested in astronomy through his uncle. His father even took up a second job to pay for the materials of a telescope that Clyde built himself. He made drawings of the planets and sent it to Lowell Observatory: astronomer VM Slipher then offered him a position as junior observer.

He partook in a program to find the elusive “Planet X”. It called for the photographing of a small piece of the night sky every evening...  He would then compare the photos to see if any of the dots appeared out of line, compared to the previous photos taken of the same area.  After 10 months of arduous work, his patience paid off and he was awarded with the discovery of the planet Pluto. It was announced on March 13, 1930.

Clyde discovered Pluto without even having a university degree.  In his spare time he did however, study science and obtained a doctor’s degree later on.  It is said that he was a very interesting person to be around with and had a colorful personality.
 
An article on Clyde Tombaugh on the internet:  http://www.icstars.com/HTML/icstars/graphics/clyde.ht

Picture at left: Clyde Tombaugh at Lowell Observatory (source).

4. The Solar System: Mercury

Mercury from space (JPL/NASA)

Now the Smallest of them all: the Planet Mercury

Mercury is the nearest planet to the Sun and has an eccentric elliptical orbit taking it as close as 47 million km and as far as 70 million km. It is also the fastest planet travelling around the Sun at a speed of 50 km/s! How would you enjoy a flight from Bloemfontein to Kimberley in just over 3 seconds?

Because Mercury is so close to the Sun, daytime temperatures can reach staggering heights of over 400 °C!  During the night however, temperatures can drop to minus 183 °C. The planet has virtually no atmosphere to retain accumulated warmth. It is a small, rocky and barren planet, similar in many respects to our Moon. Mercury too has thousands of impact craters littering its very old surface. There are also no plate tectonics on Mercury.  Only one American satellite (Mariner 10) has ever visited the planet, with 3 fly-by's in 1974 and 1975 (Mariner 10). Mercury is the second densest planet, surpassed only by Earth.

The MESSENGER space probe is on its way to Mercury, but will only arrive there in 2011.

Source and more Mercury information: http://www.nineplanets.org/mercury.html

5. Sky Observation Log

Planets - September 2006
Mercury is visible in the evening sky from the end of the 2nd week.
Venus is visible in the morning sky until mid-month.
Earth is visible 365 days of the year, mornings and evenings. That is if you are living on it!
Mars is only visible during the first week of the month in the evenings.
Jupiter shines bright in the evening sky, for the whole month. Look in the west.
Saturn is visible in the morning sky.

Constellations and stars - evenings of September 2006
To the North: Lyra (the Harp), with the bright star Vega is clearly visible to the north, setting in the west later at night. Trailing Lyra is the exquisite constellation of Cygnus, the Swan, with its many telescope objects. Pegasus, the flying horse, is rising in the east.
Mid-sky: Ophiuchus, the Serpent holder, is overhead and to the west. Aquila, the Eagle, follows shortly after. Capricornus, the Goat, is an easy target for beginners as it forms a huge "triangle" in the sky.
To the South: Pisces Austrinus, the Southern Fish, with its bright star Fomalhaut, is visible to the south-east.  Close by is Grus (the Crane bird) and the constellation of Phoenix is rising.

Deep sky Objects - September  2006
Look for M57 with an 8 inch and larger telescope in Lyra. Similarly, find M27 - the Dumbbell nebula, in Vulpecula - a large fuzzy planetary.  Sweep through Ophiuchus with your finder to see how many globular star clusters you can locate.  Observe NGC 55 and NGC 253, two large galaxies, in Sculptor. Use a binocular to scan the Milky Way region and Discover! the night sky on your own...

Recommended: a telescope with 6 to 8 inch aperture and up. Unsure where to get high-quality telescopes at a reasonable price? Contact SpaceTides to point you in the right direction.

Other night sky events
- Full Moon on 7 September 2006. New Moon on 22 September 2006.
- Partial lunar eclipse on 7 September 2006. Annular solar eclipse on 22 September 2006 - Bloemfontein can expect a 48% coverage.
Please consult the Sky Guide Africa South for detailed events and info.

6. Amateur Astronomers' Corner

So what's all this fuzziness about!?

Scene 1: On the first night, John X sits in front of his computer and see the Hubble picture of the Dumbbell planetary nebula. John X cannot believe the utter beauty and eye-popping esthetics he has just witnessed... Suddenly he almost feels a more content and fulfilled person, but he needs to see this thing for himself.  Scene 2: On the second night our dear Jonathan goes to an open evening organised by the local amateur astronomy club. The operator points it to M27 and cries "Wow, absolutely stunning! The seeing is SO good this evening". John cannot wait to look through the 10 inch. He casts his eye upon the eyepiece and suddenly, John stands utterly anti-amazed at the faint hairy fuzziness before him. He experiences the same feeling that a Hollywood fan gets when he sees his favourite actress being arrested for drunk driving.

Surely you've come across this situation: how to fulfill the expectations before an open-evening? Here's a few tips: i) Describe the object with typical amateur astronomer exuberance before showing it to the crowd. Focus on the "wow facts" - your enthusiasm will carry over to the would-be amazee. Have your facts handy. ii) While focusing the object, tell them how stunning it appears through the eyepiece!  iii) After they had their first look, show them the Hubble picture and let them look again. This is true for especially nebulae, in order to clarify the structure and outline of the object. iv) Let the emotional extrovert in the group have the first look... v) Explain why they don't see colour and detail.  vi) Enjoy the sense of personal appreciation that only an amateur astronomer can have!

7. Astronomy in Southern Africa

The Friends of Boyden Observatory

The Friends of Boyden was established in 1996 as an interest group involved in the public outreach activities of Boyden Observatory. The Friends played a crucial role in ensuring the future existence of one of South Africa's greatest astronomical landmarks, Boyden Observatory.

Membership is open to any interested person. Members are kept up to date of the latest public Boyden news & events and hold exclusive meetings where astronomy and science talks are presented. The society also works hand-in-hand with ASSA Bloemfontein Centre in assisting Boyden with certain public open evenings. Go to the Friends' website at www.assabfn.co.za/friendsofboyden.

The 10 year anniversary of the Friends will be celebrated during a special dinner event at Kopano Nokeng Country Lodge near Bloemfontein on 29 September 2006. More information.

The ASSA Symposium affords astronomy enthusiasts the rare opportunity to get
behind the scenes of SA astronomy.  Base cost is R300 per person, with an additional
R170 optional meals. You can also attend Friday's keynote session when Dr. Adrian Tiplady (SKA/KAT),
Prof. Phil Chalres (SAAO) and Prof. David Block (WITS) will deliver exciting and informative astronomy
talks from 11h00 to 15h00. The cost is R70 per person, which includes a lunch together with the Symposium's participants.  See the website at www.assabfn.co.za/symposium2006 or contact Gerrit Penning on 084 429 9080.

8. Photo Sense

A Hubble Space Telescope photo of an active star forming region in the Large Magellanic Cloud, a satellite galaxy of our Milky Way galaxy. This specific region is called N 180B, and contains some of the brightest star clusters ever discovered. Some of the hottest stars here can be a million times brighter than our own Sun. These stars vent out powerful stellar winds that clear out nearby material and cause interstellar gas to ionize and glow. From UniverseToday.com. Image credit: NASA/ESA/STScI/AURA.

9. Web Links

Inflatable Space Modules? You might be looking at the future of spaceflight... http://news.bbc.co.uk/1/hi/technology/5173388.stm

Eric Weisstein's World of Astronomy - covering various interesting topics... http://scienceworld.wolfram.com/astronomy/

PlanetQuest - the Search for another Earth... http://planetquest.jpl.nasa.gov/index.cfm

Logarithmic Maps of the Universe (for advanced readers) - J. Richard Gott... http://www.astro.princeton.edu/~mjuric/universe/

Urban legends: How they start and why they persist... http://www.livescience.com/othernews/060827_urban_legends.html

Hubble Space Telescope Pictures. A top site for Hubble pictures.... http://hubblesite.org/

Cartes du Ciel star map program. A free, rather sophisticated program to generate sky maps with... http://www.ap-i.net/skychart/