© Courtesy of Julia SteenbergSmall grains of shocked quartz buried deep under ground in Inver Grove Heights, Minn., are evidence of an ancient meteorite impact in the area
The discovery came as scientists were updating geologic maps of Dakota County. They identified anomalies in the rock record — certain layers appeared out of order or irregularly sized. This led to further examination and the identification of small grains of shocked quartz, which is known to be produced only by the extreme shock and compression of a meteorite impact or nuclear explosion.
"It's really exciting and new," geologist Julia Steenberg told MPR News host Cathy Wurzer. Steenberg and her colleagues are hoping to do more research to better understand the age of the impact and the size of the meteorite involved.
Globally, known meteorite impact sites are exceptionally rare. This is the first identified in Minnesota and one of fewer than 200 in the world.
Comment: Two further videos have been added to the AMS website.
Credit: Didine&Cec 13640
Credit: Aixam
This event has been detected by 9 cameras of the FRIPON network. All results obtained by this network for this event are available on the FRIPON Website.
Detection date: 2021-04-24 20:26 UT - Velocity: 21,245.40 m/s
Click the icons on the map for info about the stations. The trajectory computed by Fripon is represented by on the map.