Fragments of the Solar System Meteorites Fragments of the Solar System

Dedicated to Dr. Elbert King First director of the Lunar Receiving Lab Recovered a lot of Allende!! Meteoriticist

Meteorites Meteoroids Meteors Meteorites “small” rocks orbiting in space Meteors “rocks” entering the atmosphere and glowing Most are the size of a grain of sand Some are a lot bigger!!! Meteorites Rocks from space that have hit the Earth

Thunderstone of Ensisheim 1492

Thunderstone of Ensisheim What’s left of it

What Holbrook supposedly looked like 1946

Famous painting of the Shikote-Alin meteorite on a USSR postage stamp.

Meteorites Irons iron + nickel Stoney Irons Stoney Mesosiderites MES silicate + iron Pallasites PAL iron + silicate (olivine) Stoney Chondrites silicate + some iron (sometimes) Ordinary Chondrites H, L, LL Carbonaceous Chondrites C, CO, CV, CM, CK Others – Enstatite Chondrites E – Rumruti R Achondrites HED – from Vesta SNC – from Mars ALUN – from the Moon

Irons Cape York – “discovered” by Peary from Greenland actually discovered by local Inuit

Irons

Irons

Irons Witmanstatten Patterns Gibeon

Irons Willamette

Irons Hoba – 60 tons Campo del Cielo

Stony Irons Mesosiderites - MES Silicate based – with a lot of metal running through it. NWA1879

Stoney Irons Another mesosiderite -MES

Stoney Irons Mesosiderite Morristown

Stoney Iron Pallasites Iron based – with olivine crystals sprinkled through Thought to be from the core- mantle boundary of the parent asteroid

Stoney Iron Pallasite – lit from behind

Stoney - Chondrites Ordinary Chondrites H (High Metal) – L (Low Metal) – LL (Very Low Metal) Inside (Brecciated) Outside (Crusted) Probably a L4-5 – this comes from NWA – Morocco

Chondrules / Chondrites

Stoney - Chondrites Carbonaceous chondrites Residue from the formation of the Solar System – 4.5+ Billion Years old Murcheson – CM2 Allende – CV3.2

Stoney - Achondrites HED Howardite DAG 844 Meteorites from Asteroid 4 Vesta HED Howardite DAG 844

Stoney - Achondrites HED Eucrite Millbillillie

Stoney - Achondrites HED Diogenite Johnstown

Stoney - Achondrites Meteorites from Mars SNC Shergottite Zagami

Stoney - Achondrites SNC DAG 476 Dhofar 019

Stoney - Achondrites Meteorites from the Moon ALUN DAG 400

How do we know they are from Mars / the Moon / 4 Vesta?? Mars: Viking 1 and 2 had soil and atmosphere analyzers. The percentages of the elements and isotopes are the same as the SNC meteorites – and different from others! The Moon: Same story – except we have real moon rocks to compare them to Vesta: Spectroscopy of Vesta indicates it is made of HED materials, and no other asteroid is. Recent studies show a great crater on Vesta where some of these materials must have been ejected from.

How to Study Meteorites What does it look like (big picture) What does it look like (microscope) What elements are in it (chemistry and microprobe) What isotopic ratios are there (microprobe) Where did it come from (compare to asteroids and planets) How did it fall (distribution)

Meteorites / Meteorwrongs Meteorites are not hot when they hit the earth! Almost all meteorites are magnetic! Almost all meteorites have some visible metal (though sometimes only a little). Most meteorites are denser than local rocks. Meteorites don’t have holes/bubbles in them. For real analysis you have to take it to an expert

How to Study Meteorites Thin Sections – The coolest way to look at meteorites is in “thin section”. Take a thin slice of the rock, glue it to a microscope slide and grind/polish it until it is 30 micrometers thick. You can then look at it under a “petrographic microscope” with crossed polarizing filters. The colors tell you the minerals!

Eucrite Enstatite

Richfield LL3.7

Pultusk

SNC

Some chondrules in thin section

Eucrite thin section Looks a lot like Kilauea basalts!

Apollo 17 Basalt

Apollo 12 Basalt

Impact!!! When a Big rock hits – 50 meters or more – it can make a rather big hole in the ground!!!!

Meteor Crater

Wolf Creek

Lake Manicoagan

Chixilub

Brent Crater

Pretoria “Saltpan”

Sudbury + Lake Wanapitei

Disclaimer Aloha I put together these power points for use in my science classes. You may use them in your classes. Some images are public domain, some are used under the fair-use provisions of the copyright law, some are mine. Copyright is retained by the owners! Ted Brattstrom