Chicxulub crater in the context of "Asteroid impact"

A paleotsunami is a tsunami that occurs prior to written history where there are no documented observations. Paleotsunamis are evidenced by modern technology and scientific research. One of the largest was a megatsunami resulting from the asteroid that wiped out the dinosaurs.

Studying paleotsunamis is an emerging science to identify and interpret paleotsunami deposits. There are several recorded paleotsunami records, though some are known only by historical mentions, such as tsunamis resulting from the 1700 Cascadia earthquake which is known only from oral traditions among the Native Americans of the Pacific Northwest and simultaneous Japanese accounts of the same event.

An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effect. When large objects impact terrestrial planets such as the Earth, there can be significant physical and biospheric consequences, as the impacting body is usually traveling at several kilometres per second (km/s), with a minimum impact speed of 11.2 km/s (25,054 mph; 40,320 km/h) for bodies striking Earth. While planetary atmospheres can mitigate some of these impacts through the effects of atmospheric entry, many large bodies retain sufficient energy to reach the surface and cause substantial damage. This results in the formation of impact craters and structures, shaping the dominant landforms found across various types of solid objects found in the Solar System. Their prevalence and ubiquity present the strongest empirical evidence of the frequency and scale of these events.

Impact events appear to have played a significant role in the evolution of the Solar System since its formation. Major impact events have significantly shaped Earth's history, and have been implicated in the formation of the Earth–Moon system. Interplanetary impacts have also been proposed to explain the retrograde rotation of Uranus and Venus. Impact events also appear to have played a significant role in the evolutionary history of life. Impacts may have helped deliver the building blocks for life (the panspermia theory relies on this premise). Impacts have been suggested as the origin of water on Earth. They have also been implicated in several mass extinctions. The prehistoric Chicxulub impact, 66 million years ago, is believed to be the cause not only of the Cretaceous–Paleogene extinction event but acceleration of the evolution of mammals, leading to their dominance and, in turn, setting in place conditions for the eventual rise of humans.

Asteroid impact avoidance encompasses the methods by which near-Earth objects (NEO) on a potential collision course with Earth could be diverted, preventing destructive impact events. An impact by a sufficiently large asteroid or other NEOs would cause, depending on its impact location, massive tsunamis or multiple firestorms, and an impact winter caused by the sunlight-blocking effect of large quantities of pulverized rock dust and other debris placed into the stratosphere. A collision 66 million years ago between the Earth and an object approximately 10 kilometers (6 miles) wide is thought to have produced the Chicxulub crater and triggered the Cretaceous–Paleogene extinction event that is understood by the scientific community to have caused the extinction of all non-avian dinosaurs.

While the chances of a major collision are low in the near term, it is a near-certainty that one will happen eventually unless defensive measures are taken. Astronomical events—such as the Shoemaker-Levy 9 impacts on Jupiter and the 2013 Chelyabinsk meteor, along with the growing number of near-Earth objects discovered and catalogued on the Sentry Risk Table—have drawn renewed attention to such threats. The popularity of the 2021 movie Don't Look Up helped to raise awareness of the possibility of avoiding NEOs. Awareness of the threat has grown rapidly during the past few decades, but much more needs to be accomplished before the human population can feel adequately protected from a potentially catastrophic asteroid impact.

The Alvarez hypothesis posits that the mass extinction of the non-avian dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the impact of a large asteroid on the Earth. Prior to 2013, it was commonly cited as having happened about 65 million years ago, but Renne and colleagues (2013) gave an updated value of 66 million years. Evidence indicates that the asteroid fell in the Yucatán Peninsula, at Chicxulub, Mexico. The hypothesis is named after the father-and-son team of scientists Luis and Walter Alvarez, who first suggested it in 1980. Shortly afterwards, and independently, the same was suggested by Dutch paleontologist Jan Smit.

In March 2010, an international panel of scientists endorsed the asteroid hypothesis, specifically the Chicxulub impact, as being the cause of the extinction. A team of 41 scientists reviewed 20 years of scientific literature and in so doing also ruled out other theories such as massive volcanism. They had determined that a space rock 10–15 km (6–9 mi) in diameter hurtled into earth at Chicxulub. For comparison, the Martian moon Phobos has a diameter of 22 km (14 mi), and Mount Everest is just under 9 km (5.6 mi). The collision would have released the same energy as 100,000,000 megatonnes of TNT (4.2×10 J), over a billion times the energy of the atomic bombs dropped on Hiroshima and Nagasaki.

Chicxulub Puerto (Spanish: [tʃikʃuˈlub ˈpweɾto] ) is a small coastal town in Progreso Municipality in the Mexican state of Yucatán. It is located on the Gulf of Mexico, in the northwestern region of the state about 8 km (5 mi) east of the city port of Progreso, the municipality seat, and 42 km (26 mi) north of the city of Mérida, the state capital. According to the INEGI census conducted in 2020, the port town had a population of 7,591 inhabitants.

Chicxulub Puerto is most famous for being near the geographic center of the Chicxulub crater, an impact crater discovered by geologists on the Yucatán Peninsula and extending into the ocean. It was created by the impact some 66 million years ago of the Chicxulub impactor, an asteroid or comet which caused the Cretaceous–Paleogene extinction event, which led to the extinction of all non-avian dinosaurs. Chicxulub Puerto lies almost exactly on the geographic center of the crater, and has used its notoriety for tourism, having opened tourist attractions such as a museum dedicated to the meteor impact.

The Vredefort impact structure is one of the largest impact structures on Earth. The crater, which has since been eroded away, has been estimated at 170–300 kilometres (110–190 mi) across when it was formed, the latter estimate suggesting the initial crater was larger than Chicxulub crater, the largest mostly intact impact crater on Earth. The remaining structure, comprising the deformed underlying bedrock, is located in present-day Free State province of South Africa. It is named after the town of Vredefort, which is near its centre. The structure's central uplift is known as the Vredefort Dome, which is around 100–120 kilometres (62–75 mi) in diameter. The impact structure was formed during the Paleoproterozoic Era, 2.023 billion (± 4 million) years ago. It is among the oldest known impact structures on Earth, after Yarrabubba (2.23 billion years old) and possibly Miralga.

In 2005, the Vredefort Dome was added to the list of UNESCO World Heritage Sites for its geologic interest.

Glen Penfield is a geophysicist best known for his role in the discovery of the Chicxulub crater, a massive impact structure located on the Yucatán Peninsula in Mexico. This crater is widely accepted as the impact site of the asteroid that contributed to the Cretaceous–Paleogene (K–Pg) extinction event approximately 66 million years ago, which led to the mass extinction of non-avian dinosaurs and many other species.