Dear SpaceTides Subscribers

All the best for the year 2006 from SpaceTides.  Hope everything turns out as planned (and if it doesn't, it might indicate either bad planning or inadequate follow-through of the planning.)

Astronomy enthusiasts in South Africa can look forward to another exciting year in astronomy - lot's of events and happenings on Earth and in the sky to look forward to. SpaceTides will keep you informed of any dates worth mentioning.

Congratulations to our 2006 Sky Guide lucky draw winners. They are C Mill, C Verwoerd and J Naudé. You have been contacted and your copy of the Guide should either be in the post or you might already have received it. If you don't receive it by end of January, send us a mail.

Gerrit Penning

Editor: SpaceTides Newsletter;  Member: ASSA Bloemfontein Centre
spacetides@assabfn.co.za

Total subscribers as at 19 January 2006: 394 (+14 from previous issue, no. 37)
(When the subscriber count reach 400, SpaceTides will be unofficially upgraded to "e-zine status" as compared to an e-newsletter).

Launch vehicle of the New Horizon's spacecraft. JPL/NASA

To Pluto and Beyond: New Horizon set to blast off

New Horizon's Homepage: http://pluto.jhuapl.edu/, 19 January 2006

 Humans have sent unmanned probes to each and every known planet in the solar system, except for Pluto.  The best photos of planets usually come from satellites that either flew by, orbited or even landed on them, but for Pluto we have to make do with ground-based telescope images.

Not for long! Finally, after (too many) years, a spacecraft is ready to launch towards Pluto.  It won't arrive there any time soon though. The probe will be traversing space for over 10 years before reaching Pluto!  As indicated on New Horizon's website:

" Planetary exploration is a historic endeavor and a major focus of NASA. New Horizons is designed to help us understand worlds at the edge of our solar system by making the first reconnaissance of Pluto and [it's moon] Charon - a "double planet" and the last planet in our solar system to be visited by spacecraft. Then, as part of an extended mission, New Horizons would visit one or more objects in the Kuiper Belt region beyond Neptune."   More at:  http://pluto.jhuapl.edu/overview/whyGo.html

 Launch is slated for today, January 19, 2006. Hold thumbs! We live in exciting times.

Dark matter in the high-redshift cluster CL 0152-1357. Gravitational lensing analysis with the Advanced Camera for Surveys (ACS) reveals the complicated dark matter distribution (purple) in unprecedented detail.

Fossil Galaxy Reveals Clues to Early Universe
From John Hopkins University New Release, 9 December 2005

(A difficult topic for this month's edition: Dark matter! If any of you know anything about it, you know more than I do. Sounds fascinating though, something to really read up on.  - GP)

Using the Hubble Space Telescope, astronomers have mapped the location of "invisible dark matter" in extreme detail in two very young galaxy clusters.

A research scientist said the team measured the subtle gravitational 'lensing' apparent in Hubble images: the small distortions of galaxies' shapes caused by gravity from unseen dark matter - to produce its detailed dark matter maps.

The study supports the theory that dark matter (which makes up 90 percent of matter in the universe) and visible matter should coalesce at the same places due to gravity pulling them together. Concentrations of dark matter should attract visible matter, and as a result, assist in the formation of luminous stars, galaxies and galaxy clusters.   http://www.jhu.edu/news_info/news/home05/dec05/darkmatt.html

One of the Voyagers. JPL NASA

The Voyager spacecraft
The two Voyager space probes are still functioning, after being operational for more than 10 000 days.
Operations mainly consist of sending back weak signals about the spacecraft's environment. As of November 2005 (http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm) Voyager 1 was 14.5 billion km from the Sun and Voyager 2 was 11.6 billion km away. To compare - Pluto is about 6 billion km (40 AU's) from the Sun.  They are not very far in cosmic terms though. It will take them 40 000 years just to reach a distance equal to half-way (2 light years) between the Sun and our nearest star Alpha Centauri.

 On 17 February 1998, Voyager 1 passed Pioneer 10 to become the most distant human-made object in space.

               From (with more information and diagrams):   

               http://voyager.jpl.nasa.gov/mission/interstellar.html

• Why are planets round?
  Planets are round due to their gravitational fields.  Its centre of gravity is constantly "pulling" on the massive planet. The best way to get all the planet's material as close as possible to the centre is to let the materials form a sphere. The process is called "isostatic adjustment".  (extract from Scientific American's "Ask the Experts" book).

• How hot is the Sun?

The Sun is a ball of "burning" gas about 1.4 million km in diameter. Fortunately for us the Sun is quite an ordinary middle-of-the-road type of star: if it was 10 times bigger, it would already have burned up most of its fuel. If it were 10 times smaller, it would not have emitted enough light and energy for life to exist on Earth.  The Sun's heat at its photosphere (surface) is a "mere" 6 000 degrees Celsius (not much if you compare it to a Space Shuttle's engine which can become 3 400° C). The centre of the Sun is a different story though: 15 million° C! Not the best place to hang out in summer. Or winter! I'm sure the people from Upington won't mind the temperature though.

January Planets:
For the second part of January, Mercury is not visible due to the glare of the Sun. From the 4th week in January, Venus becomes the "morning star".  The Earth is the planet you probably reside on at the moment (except if you intercepted this e-mail with your spaceship out there in the asteroid belt) and if you look down, you should be able to clearly see it.  Mars can be seen in the evening sky, with a peculiar red shine (it is now a good time to observe Mars).  Jupiter is currently visible early mornings before sunrise. Saturn, the most beautiful planet through a telescope, can be seen during the evenings and all through the night from late January.  Uranus sets in the west around 21:00.  Neptune sets between 19:00 and 20:00 in the second half of the month. Pluto rises in the morning before 3:00. Note that Uranus and Neptune are not visible with the eye or ordinary-sized binoculars. Pluto requires a strong telescope.

The constellation of Orion visible above the building housing the 13 inch Alvin-Clark refractor at Boyden Observatory, Bloemfontein, SA.

January Constellations:
Constellations well placed in the evenings for observation include Eridanus (the River, a very long and difficult constellation right above you!), Orion (the Hunter), rising Canis Major (the Greater Dog), Taurus the Bull. In the south, you can try to find some of the lesser known constellations such as Phoenix, Dorado (the sword fish) Reticulum (the net or reticule), Hydrus (the sea monster) and for those up to a challenge: Sculptor and Horologium. You can also see the Large and Small Magellanic clouds quite well in the south.

Full moon on 14 January 2006. New Moon on 29 January 2006.

 Be sure to observe Saturn pass close by the Beehive cluster (M44) in the constellation of Cancer later in January 2006.

Bron:  ASSA webblad, Sterrekyk vir Januarie 2006, deur Auke Slotegraaf. http://www.saao.ac.za/assa/html/sterrekyk_2006_januarie.html

 Exposed photo showing an 11 inch reflector illuminated with a red-filtered flashlight on the observing platform at Boyden Observatory, Bloemfontein, SA. Using appropriate intensity for red lights is very important.   Credit  ASSA Bloemfontein .

 Seeing in the Dark.

Seasoned sky observers will no doubt concur that there is nothing worse than the shine of a streetlamp directly in your eyes while you're trying to get a hold of that eluding faint little fuzzy.
It can take up to 20 minutes for your eyes to properly adapt to dark conditions. Here are a few tips on making the most of that precious dark spot:  Make sure you take everything with you when going outside to avoid having to go back into the house. In your observing location, consider blocking out unwanted light with sails or canvas bought from a hardware store.  Using the right red-filtered flashlight is also crucial. Invest in proper lighting and your observing sessions will be much more convenient.  If using a computer, make sure you use the software program's night vision option to change the screen to acceptable colours. 

 And last but not least: do yourself a favour now and then and drive out of the city in order to see how life should REALLY look like at night! If you do drive out, rather go south of the city lights - the southern parts of the sky, as well as the part above your head, usually contains the best objects for observing through a binocular or telescope.

SAASTA

"The South African Agency for Science and Technology Advancement (SAASTA) aims to advance public awareness, appreciation and engagement of science, engineering and technology in South Africa". It is an agency of the National Research Foundation (NRF). " The NRF is the key public entity responsible for supporting human resource capacity for research, technology and innovation development in the fields of science and technology." SAASTA boasts an impressive website which can be found at http://www.saasta.ac.za/

Be sure to check out the Science Photography competition before 27 Jan 06!