Sedan Crater is the result of the Sedan nuclear test and is located within the Nevada Test Site, 12 mi southwest of Groom Lake, Nevada (Area 51). The crater was listed on the National Register of Historic Places on March 21, 1994. The crater is a man-made object that can be seen from earth orbit with the unaided eye.
The crater was listed on the National Register of Historic Places 25 years ago from this year being 2019.
2019 minus 1994 is 25 so it is correct but the AI couldn't do the math so marked it incorrect.
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