An Asteroid to Rule Them All

Scientists have new insight into the damage caused by a Rhode Island–size asteroid impact more than 3 billion years ago, making the rock that wiped out the dinosaurs look like a lightweight.

The massive asteroid impact wiping out the dinosaurs 65 million years ago is a big chapter in Earth’s history, but scientists have also studied hints of bigger events that could have changed Earth’s geologic evolution before dinosaur extinction. Now, in a new study from Stanford University scientists, researchers have taken a closer look at the effects of such an impact event some 3.26 billion years ago.

http://sites.agu.org/newsroom/files/2014/04/14-20-combo-graphic-2000-pixels.jpg

A graphical representation of the size of the asteroid thought to have killed the dinosaurs, and the crater it created, compared to an asteroid thought to have hit the Earth 3.26 billion years ago and the size of the crater it may have generated. A new study reveals the power and scale of the event some 3.26 billion years ago which scientists think created geological features found in a South African region known as the Barberton greenstone belt.
American Geophysical Union

In dimensions alone, this older asteroid makes the Chicxulub impactor look wimpy — it measured in at between 37 km to 58 km (23 miles to 36 miles) wide, a good three to five times larger. That’s close to the size of Rhode Island. The impact from such a rock would have created a jolt greater than a magnitude-10.8 earthquake, and the seismic-like waves would have lasted for roughly 15 minutes. Its affects would have been cataclysmic and devastating to the environment worldwide — imagine the classic end-of-the-world scenario. The crater itself would have been just under 500 km (300 miles) wide, about four times the size of the Big Island of Hawaii.

Evidence for this Earth-changing event remains preserved in the rocks of the Barberton greenstone belt in South Africa (located east of Johannesburg, near the border with Swaziland). The geologic structure of the Barberton region implies that the region was underwater when the impactor struck. The cosmic punch fractured the rock, and liquefied sediment filled these cracks, later solidifying and forming sheets of rock called chert dikes that are present today.

The study, coauthored by Stanford scientists Norman Sleep and Donald Lowe, is one of the first to model an impact occurring during this period of Earth’s evolution. Furthermore, scientists think that the asteroid could have been one of some final punches to hit Earth at the very tail end of the aptly-named Late Heavy Bombardment period (3 to 4 billion years ago).

You can read more about the study in the American Geophysical Union’s press release (first paragraph below). The paper will appear in an upcoming Geochemistry, Geophysics, Geosystems.

AMERICAN GEOPHYSICAL UNION RELEASE:
Scientists Reconstruct Ancient Impact That Dwarfs Dinosaur-extinction Blast
Picture this: A massive asteroid almost as wide as Rhode Island and about three to five times larger than the rock thought to have wiped out the dinosaurs slams into Earth. The collision punches a crater into the planet’s crust that’s nearly 500 kilometers (about 300 miles) across . . .
Read the full press release.

 

6 thoughts on “An Asteroid to Rule Them All

  1. michael-Gordon

    wonderful, the style and level of your writing is approaching the literacy of the National Geographic..
    (you know…”Nat Geo”) soon will you be “Sky Tel”?
    Michael Gordon

  2. Roy RobinsonRoy Robinson

    Calling a rock that is 45+/- km in diameter only five times as large as one 10 km in diameter is a bit misleading. The volume, mass, kinetic energy and potential for destruction are more like 100 times as great.

  3. Linvan

    Maybe a little Bible study would help you understand how closely related science and the Bible are. Intelligent scientists are agreeing. In any case everyone needs to realize that all will be revealed in the end. Basic Instructions Before Leaving Earth (BIBLE)

COMMENT