How the Moon Got Its Concentric Rings
https://eos.org/research-spotlights/how-the-moon-got-its-concentric-rings
Source: By Emily Underwood, Eos/AGU.
Excerpt: The Moon is pockmarked with impact craters from collisions with meteorites and asteroids, some as big as 1,000 kilometers in diameter. These massive impact craters contain three or more concentric rings, a mysterious feature that has long intrigued scientists interested in how Earth’s early surface and those of other planets evolved. Now a new study, in which scientists simulated an asteroid bigger than New York City slamming into a Moon-like object, explores how such rings form. ...To get a fresh perspective on this complex crater structure, Johnson et al. took advantage of data from NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission: two washing machine–sized spacecraft that orbit the Moon and produce a high-resolution map of its gravitational field. Using this new, 10-kilometer-scale data, the authors were able to build a high-resolution computer model of a 64-kilometer-diameter asteroid hurtling into a Moon-like object at 15 kilometers per second. The team found that the dominant hypothesis for how concentric rings form in impact craters, known as ring tectonic theory, appears to be correct. In this hypothesis, rings are formed as rock flows inward during crater collapse, dragging the base of the lithosphere—a planet’s or moon’s rigid, outermost rock shell—and creating a distinctive pattern of faults in the rock, forming rings....
Source: By Emily Underwood, Eos/AGU.
Excerpt: The Moon is pockmarked with impact craters from collisions with meteorites and asteroids, some as big as 1,000 kilometers in diameter. These massive impact craters contain three or more concentric rings, a mysterious feature that has long intrigued scientists interested in how Earth’s early surface and those of other planets evolved. Now a new study, in which scientists simulated an asteroid bigger than New York City slamming into a Moon-like object, explores how such rings form. ...To get a fresh perspective on this complex crater structure, Johnson et al. took advantage of data from NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission: two washing machine–sized spacecraft that orbit the Moon and produce a high-resolution map of its gravitational field. Using this new, 10-kilometer-scale data, the authors were able to build a high-resolution computer model of a 64-kilometer-diameter asteroid hurtling into a Moon-like object at 15 kilometers per second. The team found that the dominant hypothesis for how concentric rings form in impact craters, known as ring tectonic theory, appears to be correct. In this hypothesis, rings are formed as rock flows inward during crater collapse, dragging the base of the lithosphere—a planet’s or moon’s rigid, outermost rock shell—and creating a distinctive pattern of faults in the rock, forming rings....