In this issue of SpaceTides

1. Spaceflight news from around the world

Image credit: NASA/JPL

"Voyager Spacecraft Enters Solar System's Final Frontier"
From NASA/JPL News release, May 24 2005
Read the full article at: www.jpl.nasa.gov/news/news.cfm?release=2005-084

The Voyager 1 space probe, launched in 1977, arrived at Jupiter in 1979 and went on to visit Saturn in 1980. Already far past the orbit of Pluto, Voyager 1 has now entered a region of the far outer solar system, where the magnetic field intensifies and the solar wind is drastically slowed and becomes super-heated. The probe crossed what is known as the "termination shock" during December 16, 2004, and entered the "heliosheath" - an unchartered region of the outer solar system. It takes data 13 hours to travel the 14 billion kilometers to Earth from Voyager 1.

Image credit: NASA/JPL

Return to Flight: The next Space Shuttle mission rolling out...
www.nasa.gov/returntoflight/main/index.html

The last shuttle flight took place in late January 2003. Shuttle Columbia met a tragic fate upon re-entry into the atmosphere. But shuttle flights are about to resume: at NASA's Kennedy Space Centre in Florida, preparations are made to roll out Space Shuttle Discovery to the "Vehicle Assembly Building" on Thursday, May 26. Launch is slated for July 13, 2005. Discovery has completed 30 missions so far. The July mission will consist of delivering supplies to the International Space Station and making repairs.

2. Astronomy news from around the world

Image credit: NASA/JPL

Strange red spot on Saturn's moon Titan: 
May 25, 2005. Read full article at: www.jpl.nasa.gov/news/news.cfm?release=2005-086

When the Cassini spacecraft flew by Saturn's largest moon Titan on March 31 and April 16 2005, its visual and infrared mapping spectrometer observed an intriguing red spot, the brightest area ever observed on Titan. According to the JPL article, the 483-kilometer-wide region "may be a "hot" spot - an area possibly warmed by a recent asteroid impact or by a mixture of water ice and ammonia from a warm interior, oozing out of an ice volcano onto colder surrounding terrain. Other possibilities for the unusual bright spot include landscape features holding clouds in place or unusual materials on the surface".

Image credit: Optical Gravitational Lensing Experiment

Gravitational microlensing technique used to find exoplanet
May 23, 2005. Read full article at: http://cfa-www.harvard.edu/press/pr0514.html

Amateur and professional astronomers teamed up to discover a new planet circling a star 15 000 light years away (called an "exoplanet"). It was discovered by using the effect that the planet's gravitational field had on the light from a more distant star "behind it" - a technique known as microlensing. It is the 2nd exoplanet to be discovered using the microlensing technique. (In total, about 130 exoplanets have thus far been found since the first one was detected about 10 years ago, but all are mostly giant Jupiter-like gas planets). 

Astronomers discovered the exoplanet when it and its star crossed in front of a faint background star (marked by crosshairs left). The background star's light was magnified by the foreground star in a process called gravitational microlensing. The planet is 3 times the size of Jupiter, and 10 Earths can fit into the diameter of Jupiter alone!

3. Interesting Space Facts

4. Space Questions

Credit: NASA

What will happen if the Earth suddenly stops spinning?
More information: http://starryskies.com/articles/2003/09/earth.rotation.html

Most people think that the everything and everyone will just slowly drift off into space when the Earth stops spinning. Well, that's just not the case! If our planet suddenly comes to a halt, everything not very firmly fixed will simply "keep on moving" at the Earth's usual rotation speed of 1 600 km/h. That is, until you hit something at that speed!  Cars, trees, houses, loose rocks, (you!), everything will be swept away along the surface and into the atmosphere. Gravity does not give rise to the spinning effect. I better find myself a home somewhere on a koppie in the Karoo...

Credit: NASA JSC

Where in South Africa will you find one of the oldest and largest known impact craters in the world?
More information:  www.hartrao.ac.za/other/vredefort/vredefort.html

Near the town of Vredefort in the Free State Province, South Africa. The Vredefort Crater was always believed to be of volcanic origin, but recent studies deem it a meteorite crater of 300 km wide, made by a 2 km sized rock which hit the Earth about 2.1 billion years ago. Though not all remains are visually discernable from the surface, satellite pictures clearly show an arc. Interestingly enough (and not coincidentally), many of South Africa 's gold mines is situated on the rim of the old crater...

5. Web links

6. Astronomy News in South Africa

Credit: SAAO / SALT

All 91 segments of SALT's primary mirror installed
All information from the SALT website, at www.salt.ac.za/content/news/default.htm

< "The last of the 91 mirror segments has been inserted into the 11-metre primary mirror array of the Southern African Large Telescope (SALT). Each mirror segment is 1 metre wide and weighs approximately 100 kilograms.  Construction on SALT started in 2000 and the first mirror segment was installed in December 2003. The completion of SALT's primary mirror is a significant milestone in the construction of this telescope. SALT will commence operation later this year".
Visit the official SALT website at: www.salt.ac.za

7. Astronomy Events in Bloemfontein