[meteorite-list] Meteorite Found in India

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Aug 11 15:36:38 2005
Message-ID: <200508111935.j7BJZfV13051_at_zagami.jpl.nasa.gov>

http://www.navhindtimes.com/stories.php?part=news&Story_ID=08125

Meteorite found in Rajasthan
The Navhind Times (India)"
August 11, 2005

PTI Ahmedabad: Elaborate tests conducted on a meteorite fragment
found after it had crashed in Rajasthan recently has revealed it to be a
very rare iron meteorite exuding significant radioactivity. A variety of
tests were conducted by scientists of the Phyical Research Laboratory
and Basic Sciences Research Institute on the meteorite which fell at
Bhuka village in Barmer district of Rajasthan on June 25, this year.

"The results of our study indicate that it is a rare iron meteorite
having a significant radioactive content of 54 mn (manganese) and 57 co
(cobalt)," said Mr Narendra Bhandari of the BSRI.

"It seems to have originated from the asteriodal belt between Mars and
Jupiter and might have been 100 times bigger than the its present weight
of about 2.5 kg," said the scientist adding that tests were still to be
conducted to arrive at the estimated time the meteorite to travel from
the belt to Earth.

The meteorite, which fell in the farm of Mubeen Sindhi with a loud
noise, made a crater of about half-a-metre and is actually an alloy of
iron and nickel, said Mr Bhandari.

"It is the first iron meteorite to fall in Rajasthan among the seven
falls in the past 15 years," he said explaining the rareness of the
cosmic object.

The iron meteorite is the rarest of the three kinds of meteors, the
other two being stony meteors and stony iron meteors, he said.

"Moreover, for the radioactive isotopes of cobalt and manganese to be
found together in a single meteorite is very rare and it is perhaps the
first time they have been found on earth," Mr Bhandari added.

We were able to detect the radioactivity because the meteorite was sent
to us immediately after it fell, he said adding that radioactivity
slowly wanes with the passage of time.

"About 80 per cent of most meteors entering the Earth's atmosphere burn
out. What makes iron meteorite rare on Earth is because unlike stony
meteors they have a tendency to completely burn out," said Mr Bhandari
who is also the president of International Lunar Exploration Working Group.

The meteorite has a thick black crust with a golden or brownish tinge.
The crust also has well developed regmaglypts (thumb marks formed when
the meteorite enters Earth's atmosphere) typical of meteorites.

"The tests conducted on a piece of the meteorite sent to PRL (a large
chunk was also sent to the Geological Survey of India), also found it to
be made of pure iron which is very different from the kind of iron
usually found on Earth which normally exists as an oxide," he said.

The iron and nickel alloy which the meteorite is made of, was formed at
very high temperatures, in "reducing atmosphere" devoid of oxygen or
water at least four-and-a-half billion years ago. The meteorite also has
a special crystalline structure which is indicative of the slow cooling
process it witnessed, Mr bhandari said.

Talking about the meteorite's fall in June this year, he said, "This is
the seventh observed fall in the past 15 years in Rajasthan the other
six meteorite falls being at Didwana (1991), Lohawat (1994), Devri Khera
(1994), Piplia Kalan (1996), Itawa Bhopji (2000) and Bhawad (2002)."

Since only about 126 falls have been observed all over India in the past
two centuries, this frequency of falls (one every two years) in such a
small area of Rajasthan is very unusual. In comparison, no more than 10
falls have been reported from the rest of India in the past 15 years, he
observed.

Certain questions as to whether this observation is just a regional or
temporal statistical fluctuation or whether the Earth is going through
an unusually dense swarm of interplanetary bodies continues to remain
unanswered, Mr Bhandari added.
Received on Thu 11 Aug 2005 03:35:41 PM PDT