Scientists have discovered a large crater on the Earth-facing side of the Moon – the first detection of its kind in at least a century.
The previously unknown structure has been named after aviation pioneer Amelia Earhart – the first woman to fly solo across the Atlantic.
The 200km-wide buried crater was found in data from Nasa’s Grail spacecraft, which mapped the Moon’s gravity field.
The results were presented at a major scientific meeting in Texas.
“I would guess this is probably the first discovery of a crater this big on the nearside of the Moon in a century – maybe two,” Prof Melosh told BBC News.
The find was made while the scientists were searching the data for evidence of hollow underground structures known as lava tubes.
“The crater probably pre-dates the big Serenitatis basin, which is just south of it. The Serenitatis ejecta covered it up, probably destroying the southern part of the crater rim and greatly modifying it,” Prof Melosh said.
Speaking at the 46th Lunar and Planetary Science Conference (LPSC) in The Woodlands, he added: “No-one to our knowledge has ever recognised this as the broken rim of a crater, and we wouldn’t have either except that gravity shows it up very clearly as a big circular anomaly [in the Grail data].”