According to new research, the asteroid that created the Vredefort Crater was larger than the one that created the Chicxulub crater and wiped out the dinosaurs 66 million years ago. According to the researchers, the new study gives a more accurate simulation of the impact.
Simulation Model Measures an Asteroid That Hit the Vredefort Crater
According to the new study, which was published in the Journal of Geophysical Research:Planets, the asteroid that hit the Vredefort Crater was closer to 20 to 25 kilometers across and traveling at a velocity of 15 to 20 kilometers per second in the moments before impact. Earlier estimates put the asteroid's diameter at 15 kilometers and its speed at 15 kilometers per second.
According to Natalie Allen of Johns Hopkins University in Baltimore, understanding the largest impact structure on Earth is critical. Having access to the data provided by a structure like the Vredefort crater is a fantastic opportunity to put their model and understanding of geologic evidence to the test, allowing them to better understand impacts on Earth and beyond.
According to Science Alert, the numbers were crunched by the widely used Simplified Arbitrary Lagrangian Eulerian (iSALE) simulation model, resulting in a scenario that supports previous research by pushing the estimated size of the Vredefort crater to a higher range, far beyond what a 15 kilometer-wide asteroid would create.
Because two billion years is a long time for a landscape to erode, estimating the original size of the crater with precision is difficult. Its location is now covered in farmland, with only the crater's central dome visible today.
Simulation Model Provides More Accurate Data on Previous Findings
The simulations also allowed the researchers to investigate the material ejected by the impact as well as the distance traveled from the crater. This data can be used to determine the geographic locations of land masses billions of years ago.
Previous research, for example, determined that material from the impactor was ejected into present-day Karelia, Russia. Using the model, the researchers discovered that two billion years ago, the land mass containing Karelia would have been only 2,000 to 2,500 kilometers away from the South African crater, which is much closer than the two current areas.
Allen stated that it was extremely difficult to constrain the location of landmasses. The best current simulations have mapped back about a billion years, and the uncertainties grow larger as you go back further. Clearing evidence like this ejecta layer mapping could help researchers test their models and complete the picture of the past.
Undergraduate Paper Turned into a Professional Research
According to the University of Rochester, the idea for the paper arose as part of a final requirement in Nakajima's course, then-called Planetary Interiors, which Allen took as a junior.
Allen said, "When Professor Nakajima approached me and asked if I wanted to work together to turn it into a publishable work, it was really gratifying and validating. She stated that she had developed her own research idea, which was deemed compelling enough by another scientist to warrant publication."
Allen says that the experience of having her undergraduate work published in a peer-reviewed journal article was very rewarding and aided her application to graduate school.
