Mystery of odd Wisconsin rock formations solved Juliet Williams,ÊAssociated Press April 27, 2004CRATER0427 ROCK ELM, WIS. -- The muddy brown hills and rolling farmland at first look like typical Wisconsin. Farm fields and a bubb ling brook yield to rocky ou tcrops and rows of trees. But scientists years ago saw something different about those rocks and concluded that an ancient catastrophic event had occurred, although what it was remained a mystery. Now they believe they know: A 650- to 700-foot-wide meteorite crashed to Earth at speeds as h igh as 67,500 miles per hour 450 million years ago. The impact dislodged rocks and created a massive hole about 4 miles in diameter and 600 feet deep in an area called Rock Elm, 70 miles southeast of the Twin Cities, three scientists state in an article published in the Geological Society of America Bulletin. Over time, shale, dirt and sediment filled the crater to make the site virtually indistinguishable from the surrounding land. It's believed that a shallow sea covering Wisconsin at the time of the impact probably blunted the meteorite's effect. Meteorite caused rock upheavals Janet Hostetter Associated Press
Bit of Administration. Washburn Observatory Wednesday, after dusk for a few hours Reading Chapter 24, Chapter 14 recommended Discussion Section Web-lecture in advance of section 2 pts extra credit for evaluation 3 pt extra credit quiz responsible for material
THE EXTRA-SOLAR PLANET PROJECT Phase 1: Last week s quiz. Phase 2 : A Web-Lecture on Extra-Solar Planets. Learn about extra-solar planets and have opportunity to earn 5 pts extra credit. 2 pts for evaluation questions 3 pts for success on quiz Preparation for next week s discussion sections (5/3-5/7). Access: http://eteach.engr.wisc.edu/meibom/espp/index.html Speed: 300 Kbps, 100 Kbps, and 37 Kbps. The hardware requirements for viewing the lecture are: A computer with connection to the Internet. Computer speakers or headphones. The software requirements for viewing the lecture are: Windows Operating System. Internet Explorer version 5.5 or later. Power Point 2002 or later ("Power Point Animation plug-in"). Campus computer-labs: http://www.doit.wisc.edu/computerlabs/index.asp Bring headphones!
Asteroids, Comets, Meteors, and Pluto
Oort Cloud Primordial Icy Planetesimals Jupiter Forms Icy Planetesimals Rocky Planetesimals Kuiper Belt Fragmented Icy Planetesimals (KBOs) Sedna
Asteroids, Comets, Meteors, and Pluto Summary Asteroids Rocky Planetesimals Comets Long - Period = Icy Planetesimals Short - Period = Fragmented KBOs Pluto, Sedna,, Triton, Kuiper Belt Objects Icy Planetesimals Meteors Processed Iron and Stony Meteorites Fragmented asteroids Meteor Showers Fragmented comets Primitive Meteors = Rocky Planetesimals
Asteroids, Comets, Meteors, and Pluto
Asteroids, Comets, Meteors, and Pluto Meteors Showers - debris of old comets Earth orbit Past Comet
Asteroids, Comets, Meteors, and Pluto Meteors Types - Processed Meteorites Stony Meteorites 93% Just like crust of Earth Iron Meteorites 6 % Crystallization patterns => long cooling times
Asteroids, Comets, Meteors, and Pluto Meteors Types - Primitive Meteorites Stony, with trace of pure metallic flakes Carbonaceous chondrites Carbon compounds, and even water
Life in the Solar System Arguments for Life as High Probability Organic molecules form easily Carbonaceous Chondrites Allende Meteorite 2/8/69, 1:05 AM Chondrules (Amino Acids) Calcium-Aluminum Inclusions (CAIs( CAIs)
Arguments for Life Life in the Solar System Organic molecules form easily
Stromatolites (cyanobacteria) Life in the Solar System Arguments for Life as High Probability Organic molecules form easily Life occurred quickly on Earth - < 3.85 billion years 3.5 billion yr old
Life in the Solar System Arguments for Life as High Probability Organic molecules form easily Life occurred quickly on Earth - < 3.85 billion years 4.4 billion yr old zircon high oxygen isotope ratios cool water on Earth!
Life in the Solar System Arguments for Life as High Probability Organic molecules form easily Life occurred quickly on Earth - < 3.85 billion years Life can exist in a wide range of conditions
Life on Mars? Life in the Solar System Flowing water and warm conditions for 1 byr Extensive volcanos Martian meteorites ALH84001 magnetite crystals
Life on Mars? Life in the Solar System Flowing water and warm conditions for 1 byr Extensive volcanos Martian meteorites
Life in the Solar System Life on Europa? Icy crust Tidal heating Liquid oceans Volcanic vents
Life in the Solar System Life on Europa Icy crust Tidal heating Liquid oceans Volcanic vents