The proposed Hiawatha impact crater is estimated to be 19 miles wide, larger than Washington, D.C.
Notes on verification
Confirmed by NASA SVS, Science magazine, Sci.News, and Wikipedia summarizing the peer-reviewed Kjær et al. 2018 Science Advances paper. Size and DC comparison are consistently corroborated across independent sources, though crater age remains debated. [cascade flags: wikipedia_dropped_other_sources_exist | tier=silver indep_score=0.983 clusters=3 claim_tier=notable]
Sources
- City-size impact crater found under Greenland ice (seed:history_and_archaeology)
- https://www.science.org/content/article/massive-crater-under-greenland-s-ice-points-climate-altering-impact-time-humans (corroboration)
- https://svs.gsfc.nasa.gov/12941 (corroboration)
- https://www.sci.news/othersciences/geoscience/hiawatha-impact-crater-greenland-06610.html (corroboration)