About 60 miles north of the Arctic Circle in eastern Russia is Lake El'gygytgyn, which is inside a 3.6-million-year-old meteorite impact crater. The crater is about 15 kilometers (about 9.3 miles) across. “In this false-color image, red indicates vegetation, gray-brown indicates bare land, and deep blue indicates water,” NASA writes, noting that the vegetation consists of low-lying plants that make up the Arctic tundra.
Climate researchers find this impact crater particularly valuable, as its lake bed sediments contain a continuous record of past Arctic conditions. They are able to use these sediments to analyze how climate has changed over the past few million years.