Scientists Find Hottest Temperature On Earth In Meteorite Impact

A meteorite struck Earth so hard 38 million years ago that the crash caused the hottest known temperature on our planet’s surface.

Scientists calculated the heat while they were investigating an impact crater in Canada. According to a study in the journal Earth and Planetary Science Letters, the temperature caused by the meteorite strike had to be at least 4300 degrees Fahrenheit because the crash made the mineral zircon transform into cubic zirconia — and that’s the minimum temperature required for such a reaction.

“This new temperature determination is the highest recorded from any crustal rock,” the study says.

A meteorite is a space rock that makes it to Earth’s surface, not to be confused with a meteor, which is a rock that enters Earth’s atmosphere and burns up. While they are still in outer space, these objects are meteoroids or asteroids.

Meteorite impacts tell us a lot about the history and formation of the solar system and our planet. As the study notes, when the space rocks hit the ground, both they and sections of Earth’s crust instantly melt and vaporize, influencing the planet’s shape.

But that same melting and vaporizing also makes it hard to learn about the rock that hit Earth and other details about the crash site and the subsequent reaction.

In the early solar system, scientific models show that the planets and the moons were frequently smacked with rocks. About 4 billion years ago, the inner planets, were subject to a period called the late heavy bombardment, causing explosive crashes and huge craters.

However, since the scorching temperatures generated by a meteorite impact are so short-lived and high, it is difficult for scientists to measure them. As a result, according to the study, the temperatures on the Earth and the moon in these bombardment models are not very exact. If they were more precise, they could also paint a clearer picture of how the Earth’s crust evolved.

Although the crater the scientists were looking at, the Mistastin Lake crater in western Labrador, is only about 38 million years old, placing the impact much more recently in Earth’s history, it can help scientists better understand such impacts and how they shaped our planet. Because the crater is 17 miles wide, the object that smacked down was likely quite big.

It was so big that it hit hard enough to transform zircon into cubic zirconia — the scientists found evidence of that transformation as they were studying the Mistastin crater. According to a report on the research, previous research has shown that zircon needs a temperature of 4300 degrees Fahrenheit, or 2370 degrees Celsius, to make that change, so the impact had to be at least that hot.

That minimum temperature in the Mistastin crater is the hottest natural temperature ever discovered or recorded on Earth’s surface, the report said.

It was also the first time scientists have used zirconia to work backward and figure out how hot a meteorite impact was.

The scientists wrote in their study that the results are “more closely bridging the gap between nature and theory.”