Leonard David's INSIDE OUTER SPACE

Credit: NASA

“Impact Earth: A review of the terrestrial impact record” is an impressive look at impact craters and hypervelocity impact craters on Earth. Still to be revealed is the total number of these craters, and there are reasons to suspect that the terrestrial small crater record is incomplete.

Lead author of the new research carried in Earth-Science Reviews is Gordon Osinski in the Department of Earth Sciences at the University of Western Ontario, Canada.

“Over the past few decades, it has become increasingly clear that the impact of interplanetary bodies on other planetary bodies is one of the most ubiquitous and important geological processes in the Solar System,” Osinski and colleagues explain.

Images of lunar craters showing the change in morphology with increasing diameter. All images are portions of Lunar Reconnaissance Orbiter Camera Wide Angle Camera mosaics.
From paper: Credit: Gordon R. Osinski, et al.

“This impact process has played a fundamental role throughout the history of the Earth and other planetary bodies, resulting in both destructive and beneficial effects. The impact cratering record of Earth is critical to our understanding of the processes, products, and effects of impact events,” the research team adds.

Searchable database

Introduced in the new paper is the Impact Earth initiative and an Impact Earth Database. The goal of the initiative Impact Earth initiative is to provide a holistic view of impacts, from fireballs, to meteorite falls, to the largest crater-forming events.

At its core is a new searchable database of all confirmed impact sites on Earth and many of their most salient attributes, such as age, size, etc., Osinski and colleagues add.

“Given the fact that two-thirds of the Earth’s surface is covered by water, it would be expected that a large number of impact features on Earth formed in such an environment. However, the record is notably sparse,” the scientists note in the paper.

Impact record

“It can be reasoned that the impact of extraterrestrial objects with planetary bodies is one of the most fundamental and ubiquitous geological processes in the Solar System, with implications for the origin and evolution of planets and of life itself,” the researchers observe.

Credit: Impact Earth Database

The study team flags the fact that the database is a new tool that can tell us about impact cratering processes and products. While newly established, the database has already yielded important new information, for example, on the simple-to-complex crater transition diameter and the nature of complex craters on Earth.

“With the ongoing robotic exploration of two impact craters on Mars (Gale and Jezero) and the imminent prospect of humans conducting fieldwork once again on the heavily cratered lunar surface, it is our hope that as happened during Apollo, that the exploration of the Moon, Mars and other Solar System bodies will occur hand in hand with the exploration of the impact record here on Earth,” they conclude.

Schematic diagrams showing the formation of simple and complex hypervelocity impact craters.
Credit: Gordon R. Osinski, et al.

To acquire the full paper – “Impact Earth: A review of the terrestrial impact record” – go to:

https://www.sciencedirect.com/science/article/pii/S0012825222001969?dgcid=raven_sd_via_email

To access the database, go to: http://www.impactearth.com