Sutter’s Mill, California, USA
3 min read
3D view of the strewn field, showing finds
Sacramento, California – April 22, 2012, 7:51 PM local time, a large fireball was observed entering the atmosphere over central California, and ending in the hills just northeast of Sacramento. These Sierra Nevada gold fields are famous for the gold rush of 1849, following the discovery of gold flakes at Sutter’s Mill in January of 1848. Now in 2012, a new kind of treasure hunter followed the footsteps of the “forty-niners to a new kind of treasure. There’s meteorites them thar hills! Although discovered at a mill, these were not run-of-the-mill meteorites… Initial meteorite finds were quickly determined to be a very rare carbonaceous (CM) type material, which represents only 5% of meteorite finds globally.
Trajectory Data
| Entry Date/Time: | 2012-04-22 14:51:12 UTC |
| End Location: | 50 km NE of Sacramento, CA |
| Endpoint Coordinates: | 38.750°N, 120.904°W |
| Reference Altitude: | 30.1 km above sea level |
| Energy / Mass Estimate: | 20.18 kt TNT / 40000 kg |
| Reference Speed: | 28.6 km/s |
| Bearing: | 272.5° W |
| Slope: | 63.7° from vertical |
| TKW Recovered: | 993 grams |
| Estimated Strewn Mass: | < 300 kg |
| Classification: | CM Carbonaceous |
| Event Links: | SETI Article & Find Data AMS Event 588-2012 MetBull Page Science Publication |
News and Video
There is only one known video of the Sutter’s Mill event, linked below.
Search Efforts & Finds
Word spread quickly of the rare meteorite type discovered at Sutter’s Mill and meteorite hunters of all ages and experience levels descended on the area. Large group searches were organized by Dr. Peter Jenniskens of the SETI Institute and NASA Ames Research Center, and in the 10 weeks following the fall, more than 75 meteorites, totalling almost a kilogram were recovered from the Sutter’s Mill region!
Fragments of the Sutter’s Mill meteorite fall collected by NASA Ames and SETI Institute meteor astronomer Peter Jenniskens in the evening of Tuesday April 24, 2012, two days after the fall. This was the second recovered find. IMAGE CREDIT: NASA AMES/ERIC JAMES.
This article was released on the 10-year anniversary of the fireball, April 22nd, 2022, and no new finds have been reported since the initial searches in the spring of 2012. It is our hope that new search maps could renew interest in this famous strewn field and maybe lead to new finds. Refer to the sections below for details and search maps, which you can download to Google Earth.
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StrewnLAB Search Area
The trajectory for this event was estimated from the publication, Radar-Enabled Recovery of the Sutter’s Mill Meteorite, a Carbonaceous Chondrite Regolith Breccia from Science, the premier global science weekly journal. The trajectory was run through the StrewnLAB algorithm, which simulates the path of the meteor, including the affects of wind, fragmentation and ablation.
The StrewnLAB fragmentation and ablation model is not yet optimized for carbonaceous chondrites, so that may explain why no finds were discovered in the heavy end of the strewn field. I think it is reasonable to assume that much of the carbonaceous material burned up quickly and did not survive to penetrate deep into the atmosphere. A good strategy to continue searching this large area, would be to start at the known finds and work toward the yellow areas of the map.
Please download and review the Google Earth files below for detailed maps of the search area. Find data is also provided in the KMZ file, and it was sourced from the official list on the Sutter’s Mill SETI page.
Weather Data
The weather data below is sourced from weather balloons, and publicly available via NOAA’s Integrated Global Radiosonde Archive (IGRA). This data is downloaded and post-processed by the StrewnLAB algorithm, to account for changing weather patterns and weather balloon drift. The plots have altitude on the y-axis, in kilometers above sea level. The wind speed below 10km has large effect on the drift of meteorites, especially the smaller fragments.
The author and founder of Strewnify.com, an automotive controls engineer, with a passion for physics.
Hancock, Michigan, USA | james.a.goodall@gmail.com | +1 586 709 5888
