Monday, April 27, 2009

Tektites Rock! How to Find and Collect Tektites

You've probably heard of that asteroid tracked to it's explosive demise over the Sudan desert in 2008 (fragment shown at left). Only a few meters across, it didn't survive intact and shattered before it hit the ground, sending hundreds of debris strewn on the desert sand. Eventually, fragments of the doomed asteroid were recovered. It was easy because astronomers knew where it went and it also left fireball dust like in the following picture left behind by the Almahata Sitta fireball.

A lot of meteorite collectors would have scrambled to get a piece of Asteroid 2008 TC3 if they also knew where to look. But the fact is that meteorites are quite difficult to find. Usually, scientists look for them on ice fields, where they stand out starkly against the white ice. Others prefer vast stretches of sandy desert, where they also stand out like sore thumbs. But of course, not everyone has the means to travel to the North Pole or the Empty Quarter of Saudi Arabia just to hunt to meteorites.

The next best thing to collecting such souvenir rocks from space is to simply collect tektites (top pic from http://www.tektites.co.uk/). Tektites, of course, are rocks that are the result of asteroids that have impacted Earth in the past. thrown high above the atmosphere as molten globs that solidified, they form strange shapes upon reentry into the atmosphere since they are melted again. They drop to the ground, on what are called strewn fields, as odd rocks that do not match others on the ground.

Here is a table of major tektite strewn fields in the world:

Name
Location
Age
(million years)
Australasian Australia, Tasmania, Indonesia, Philippines, and most of Southeast Asia
0.75
Czechoslovakian Czech Republic 14.8
North American Texas, Georgia, Martha's Vineyard, Cuba 35
Ivory Coast Ivory Coast of Africa ~ 1.0
Libyan Libyan Desert 28.5
Irgiz North of the Aral Sea 1.07
Aouelloul Mauritania (West Africa) 3.5

If you live in a country or in a specific area that's part of a major strewn field, then you're lucky, because the chances of you finding tektites is high. In the Philippines, for instance, tektites are regularly collected and sold as amulets in Manila. People simply go and walk by the side of rivers and over fields to look for them. They are simply visually sorted out and picked up by hand from the other rocks on the ground. Most are small - an inch or two, but some can be as big as five inches in diameter or even more, although these big tektites are rare. Dr. Henry Otley Beyer (left), the renowned American anthropologist who lived with the Ifugaos, did most of the collecting of Philippinites. His collection now forms part of the National Museum displays, including those at the Planetarium at the Luneta park.

Of course, you have to know what tektites look like in order for you to find them. Most are dark and grooved, but others, like Libyan desert glass (left), are translucent and appear shattered. You can see samples of how tektites look here in this entry in Wikipedia. There you'll also see how some rocks like sandstone can have the shape, but not the texture and color of a tektite.

FACT: In the Philippines, tektites were once collected in Ortigas in Metro Manila. Today, there are the Tektite towers that stand along Exchange road to remind us of the richness of the area for tektites! You can check out one of the abstracts of the research papers where a find in the Ortigas site is mentioned, here at the SAO/NASA Astrophysics Data System. Just type the words "tektites" and "ortigas" together and you'll find it.



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Wednesday, February 18, 2009

Night Time Fun at the Harry Bayley Observatory

by The Wandering Scotsman

Last night I finally had the chance to spend an evening at the Harry Bayley Observatory here in Barbados, doing a wee bit of stargazing as well as getting the opportunity to see the moon close up.

The Harry Bayley Observatory is located in the Parish of St Michal; it is fairly easy to find, fortunately the directions we were giving over the phone were very accurate, if you head down Observatory Road you cant really miss it.

The observatory is named after Harry Bayley who founded the Barbados Astronomical Society and was built in 1963. We arrived early at about 8.45pm but things didn't really get going until 9.30pm. The observatory is only open to the public on a Friday and obviously it is only open, weather permitting.

The entrance fee was $12BDs for adults and $6BDS for children, which in my opinion was money well spent. The Harry Bayley Observatory is the only one in the Eastern Caribbean and the telescope used is a Celestron 14 inch telescope. I know they Society has long-term plans to upgrade their equipment and hopefully they will eventually raise the funds to do so.

This was my first trip to an observatory and I had been looking forward to it all week and I had been constantly checking the BBC weather forecast online to make sure the weather was going to be dry and clear. The excitement really started to kick in for me as I climbed the stairs as to the top of the observatory. As soon as I reached the top of the observatory I witnessed my first ever shooting star, what an amazing site.

Once at the top of the Harry Bayley Observatory the first thing you notice is the great nighttime view of Bridgetown. It was sure was fascinating learning about the various stars and constellations, which I have being seeing in the sky above Barbados since my arrival on the island.

I was looking out for little green men on the surface of the moon, but all was quiet and they must have been in their beds. The guys of the astronomical society are all very knowledgeable and passionate about astronomy and make it a really enjoyable and informative experience.

What I had originally thought was a satellite, was in fact Sirius, also known as the Dog Star, which is in fact the brightest star in the night time sky. Sirius appears so bright because of its closeness to earth and its luminosity. Did you know that Sirius could be seen from almost every inhabited region of the Earths surface, with only those living north of 73 degrees unable to see it.

The Harry Bayley Observatory is a fun and enjoyable evening out for all members of the family, it is something different and I will be back again in March when things will be a wee bit different up in the sky above Barbados.

Recently I have been amazed by the amount of stars that I have seen in the sky above Barbados, Star Struck In Barbados.

About the Author

I'm a budding Scottish entrepreneur now living on the Caribbean Island of Barbados trying to make a few dollars. I'm always on the lookout for business partners who are aiming to get involved in making money in Barbados through innovative business ventures.

I Garry A Wynters, "The Wandering Scotsman" and can be found at my two Barbados blogs, http://thebarbadosblog.com and the http://barbadosphotoblog.com.


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