A New Crater on the Moon, and How We Know It Wasn't There Before

NASA’s Lunar Reconnaissance Orbiter has identified a 728-foot-wide crater on the Moon that formed sometime in 2024, according to ScienceDaily, which reports it as the largest newly formed crater ever confirmed anywhere in the solar system. The impact also produced an unusually large cold zone stretching for miles around the site.

How you catch a crater in the act

The Moon has no atmosphere, no weather, and almost no tectonic activity, so its surface barely changes on human timescales — which is exactly what makes a brand-new crater so easy to spot once you know where to look. LRO has spent over a decade photographing the same terrain repeatedly, and mission scientists compare fresh images against older ones to hunt for anything that has changed. A crater this size does not creep in gradually; it appears in one frame and is absent in the last.

The cold zone is the more interesting clue, and it comes from a different instrument: LRO’s Diviner radiometer, which measures how quickly ground gives up heat after lunar sunset. Freshly excavated regolith is fluffier and less compacted than the ancient, sun-baked soil around it, so it loses heat faster and reads as anomalously cold in nighttime thermal maps — often before the crater itself is obvious in visible light. That thermal signature is what let researchers flag the site and then confirm it visually.

What a crater this size actually tells you

Crater dimensions scale with impactor size and speed in a fairly well-understood way: an object striking the Moon at typical impact velocities — many kilometres per second — can gouge out a crater roughly ten to twenty times its own diameter. A 728-foot crater implies something in the range of a large boulder or small asteroid fragment, releasing energy on the order of a modest chemical explosion, concentrated into a fraction of a second.

That matters beyond the novelty. The Moon’s cratering rate is one of the few direct, physical checks we have on how often small bodies are hitting the inner solar system, and it feeds directly into risk assessments for surface missions — including anything NASA or its partners eventually put on the ground for Artemis. A single event this size doesn’t rewrite those odds, but each confirmed fresh crater sharpens the baseline, since most of what we know about lunar impact rates still comes from counting old craters and estimating their ages, not watching new ones form.

The finding, as reported, is a size-and-location result rather than a full study of the impactor itself, and no origin object has been identified.

Reported at ScienceDaily; analysis ours.