Murchison meteorite

Author
by Ursula
Publish date
5 December 2011
Comments
Comments (5)

Ursula Smith works in the natural sciences collections at Museum Victoria. Though a palaeontologist by training she finds all the collections fascinating and swings between excitement at all the cool stuff in them and despair at the lack of time to look at it all.

I’ve been asking the people who work with MV collections what some of their favourite items are, starting with Dermot Henry, the Manager of the Natural Sciences Collections.

Dermot's speciality is geology and he’s looked after the geosciences collections for many years. When asked what his favourite item was he took care to tell me that he didn’t have a favourite because there are so many fascinating objects, but when pressed he picked the Murchison meteorite as "probably the most famous and scientifically important rock in the collections."

The Murchison meteorite is one of 16 meteorites known from Victoria, and is rare in that it was actually observed falling, rather than just being found on the ground, so it came to scientists fresh (other than some surface dirt from falling into mud and cowpats and the like). It exploded in the atmosphere over Murchison, Victoria, about 160km north of Melbourne, on 28 September, 1969 and fell over an area around 35km2. So when we talk about 'it' we’re really talking about lots of broken pieces of a single object.

  Geology exhibition display Display in Dynamic Earth.
Image: Ursula Smith
Source: Museum Victoria
 

These pieces are on display in Dynamic Earth and are just a very small portion of what was collected. The largest piece found weighed nearly 7kg though many more were just a few grams each. In total, around 100kg was collected and over 80kg of that made it into science collections. While a lot of the material went overseas (mostly to the Field Museum in Chicago who have nearly 52kg and the Smithsonian in Washington DC who have nearly 20kg) some remained in Australia. Over 7kg stayed at the University of Melbourne and much of this was later donated to Museum Victoria. We have about 3.5kg and only the largest pieces that are on display; we also have lots of smaller pieces.

Drawer containing pieces of Murchison meteorite Drawer containing pieces of Murchison meteorite.
Image: Ursula Smith
Source: Museum Victoria
 

Most of the pieces of rock in this drawer are parts of the Murchison meteorite (though not the big rock on the right – that’s actually a different meteorite of a similar type called Rainbow that was found in Victoria in 1994). Opening the sealed tubes, you can still smell, very faintly, what Dr. John Lovering from the University of Melbourne who organised the collection of the meteorite pieces in 1969 described as "just like methylated spirits – very strong". This was the first indication that the meteorite he was looking at was a rare type called a carbonaceous chondrite. Unlike more common rocky meteorites, a carbonaceous chondrite is packed full of organic molecules and a lot of water; this one is eight per cent water.

The year after it was collected, papers began to appear in scientific journals describing the chemical composition of the meteorite and excitement about its scientific significance began to grow. A paper in the journal Nature describing the discovery of amino acids of extra-terrestrial origin in the meteorite made, if you’ll pardon the pun, quite an impact, and was widely covered in the press, even making it into Time Magazine. Papers are still being published on it – one came out in August this year in the Proceedings of the National Academy of Sciences, and a new chromium sulfide mineral, Murchisite (Cr5S6), was just reported in American Mineralogist.

To date over 70 amino acids have been identified from the meteorite, only 19 of which are known from Earth. These, and the many other chemicals that have been identified, suggest there could be thousands of complex organic chemicals present. What’s so interesting about these molecules is that they demonstrate that the simple chemical building blocks necessary for life on Earth seem to form quite easily in other places.

It isn’t just the origins of life that the Murchison meteorite may tell us about. It contains tiny pre-solar grains – nano-diamonds and silicon carbides, among others, that formed in supernovas long before our own sun appeared – which tell us a lot about how our own, and other, solar systems formed. But not only that, information from the pre-solar grains in the Murchison meteorite has been fundamental in figuring out a lot about how elements are originally produced and a lot about the structure and mechanics of stars.

So the Murchison meteorite is definitely pretty cool – biologists, chemists, astrophysicists and those of us who just think rocks that fall out of the sky are fascinating all agree on that. As Dermot says, "it’s so unusual and it’s yielded so much information about cosmology, element formation and how the universe works – it’s probably generated more publications than any other meteorite. And it’s Victorian!"

Murchison meteorite pieces Two pieces of the Murchison meteorite in Dynamic Earth.
Image: Ursula Smith
Source: Museum Victoria
 

Links:

Infosheet: Meteorites

Video: The Murchison meteorite story

Dermot A. Henry, 'Star Dust Memories - a Brief History of the Murchison Carbonaceous Chondrite'. Publications of the Astronomical Society of Australia, 2003. 20: vii-ix (PDF, 1 MB)

Comments (5)

sort by
newest
oldest
Monique Webb 16 October, 2013 18:24
Hi, i'm doing a research task as well and i was also wondering what structures were found in the meteorite and why those structures made the meteorite so significant?
reply
Louise Polese 15 October, 2013 17:44
hi, i am really stuck with an reasearch task. i can seem any information that tells me what structures we found in the meteorite?
reply
Caz Donovan 12 November, 2012 18:28
I visited your museum in order to see the Murchison meteorite (found eventually with some difficulty). I was wondering why there is no date as to how old it is. I have read previously the date given as 4.6 billion years. Is there a query about this date now?
reply
Discovery Centre 1 December, 2012 11:24

Hi Caz,

The Murchison meteorite itself is the same age as our Solar System - about 4.56 billion years.  However, some of the material it is made up of contains pre-solar grains which were around long before the meteorite and the solar system formed and incorporated them. Some of these pre-solar grains are over 6 billion years old.

Lucy 6 December, 2011 14:39
So fascinating. Thanks for bringing this material to life so that I even I could "get it"! Very cool that it is Victorian, and yet has such global significance.
reply
Write your comment below All fields are required

We love receiving comments, but can’t always respond.

About this blog

Updates on what's happening at Melbourne Museum, the Immigration Museum, Scienceworks, the Royal Exhibition Building, and beyond.

Categories