Shining sand and rocks and other factors have turned Oman into a major site of meteorite discoveries, ranking second only to Antarctica in such findings over the past few years, according to an Omani study.
In the few years leading up to 2007, Oman contributed around 14 per cent of all the world’s meteorite finds excluding Antarctica finds, a figure topped only by inhospitable and hard to reach Antarctica, said the study published in Manhal bulletin of the government-controlled Petroleum Development Oman.
“That pace of discovery has fallen a little since 2007, but scientists are still building their knowledge of our planet and solar system thanks to Omani meteorite finds,” the two page study said.
“Why is Oman such a fertile hunting ground for meteorites… there are a number of reasons, but topography is the primary one.”
According to the study, the central and southern deserts of Oman are generally flat, making them relatively easy for meteorite-searchers to explore.
The sand and carbonate rocks that abound in the desert landscape, being light in colour, also provide a contrast to the dark colour that characterises meteorites.
“This makes it a little easier for a trained eye to spot rocks that could potentially be meteorites, although their true origin can only be determined by laboratory testing….meteorites are studied by taking a section from the rock and examining it using two advanced forms of microscopy – reflected light (which shows up the metals present) and transmitted light (to identify other minerals such as olivine).
The study noted that most meteorites that fall to earth are “chondrites”, named for the tiny rounded silicate particles called chondrules that they contain.
Most meteorites originate from the asteroidal belt which occurs between Mars and Jupiter, but over the years a few have been found that have travelled all the way from Mars and the Moon, it said.
“The lunar meteorite named Sayh al Uhaymir (SaU) 169 was found in Oman …it made international headlines when it was found in 2002 by three geologists, Ali Al Kathiri, Beda Hofmann and Edwin Gnos, during a joint meteorite search project by the Government of Oman and the University and Natural History Museum of Berne, Switzerland.”
The study said SaU 169’s unique composition enabled it to be directly linked to the Imbrium impact basin on the moon, thanks to rock samples taken by the Apollo 14 lunar mission, which landed nearby.
“Most large meteorites disintegrate into a shower of fragments when entering the Earth’s atmosphere. The speed and angle of entry of these fragments spread their landing over a large area, known as a strewn field,” it said.
“The footprint of one of Oman’s well known meteorite showers is called Sayh Al Uhaymir 001. Some 2,670 fragments from this meteorite have been recovered, weighing a total of more than 450kg! Not very far from them was the celebrated SaU 169….Strewn fields are elliptical in shape, with the smallest fragments touching down first and the largest being the last to hit the ground.”
What is a meterorite?
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface.
Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids.
When it enters the atmosphere, impact pressure causes the body to heat up and emit light, thus forming a fireball, also known as a meteor or shooting/falling star. The term bolide refers to either an extraterrestrial body that collides with the Earth, or to an exceptionally bright, fireball-like meteor regardless of whether it ultimately impacts the surface.
More generally, a meteorite on the surface of any celestial body is a natural object that has come from elsewhere in space. Meteorites have been found on the Moon and Mars.
Meteorites that are recovered after being observed as they transited the atmosphere or impacted the Earth are called falls. All other meteorites are known as finds. As of February 2010, there are approximately 1,086 witnessed falls having specimens in the world's collections. In contrast, there are over 38,660 well-documented meteorite finds.