All posts tagged: asteroid impacts

Lunar meteorite discovery reveals violent chapter in the inner solar system 3.5 billion years ago

Lunar meteorite discovery reveals violent chapter in the inner solar system 3.5 billion years ago

Earth’s earliest chapter is mostly gone. Rocks from the planet’s first few billion years have been eroded, buried, recycled, or dragged back into the mantle. This has left only scattered traces of the world in which life first appeared. Therefore, every surviving clue is unusually valuable, especially when scientists are trying to answer a basic question. How often did giant impacts strike the young inner solar system while life was beginning on Earth? A lunar meteorite recovered in northwest Africa is now offering one of those clues. In a study published in Geology, researchers report that the rock records a major impact on the Moon about 3.486 billion years ago. The age closely matches evidence of ancient impacts preserved on Earth. It also matches impact ages tied to 4 Vesta, the fourth-largest object in the asteroid belt. That rare overlap, the team says, helps connect the histories of three different bodies at a time when the inner solar system was still getting hammered. This happened long after the most chaotic phase of planet formation had …

Dante’s Inferno suggests Hell and Purgatory mirror the physics of a massive asteroid impact

Dante’s Inferno suggests Hell and Purgatory mirror the physics of a massive asteroid impact

For centuries, Dante Alighieri’s Inferno has been read as a moral and spiritual descent, a journey into sin, punishment, and divine justice. Timothy Burbery of Marshall University now argues that the poem also carries something far more physical. In his reading, Dante did not simply imagine Satan falling from Heaven. He pictured that fall as a violent planetary impact. That idea changes the scale of the story at once. Instead of treating Satan’s plunge as a symbolic collapse, Burbery proposes that Dante envisioned him as a fast-moving body striking the Southern Hemisphere and boring all the way to Earth’s center. In that scenario, Hell is not just a spiritual realm beneath the surface. It is the crater left behind by the collision, formed from the ground up as matter is forced outward and downward. The image is startling because it makes Dante sound less like a poet working in allegory and more like someone running a thought experiment about impact physics centuries before modern meteoritics existed. Dante and Virgil reach the ninth and lowest circle …

Martian microbes can survive being blasted into space by a large asteroid strike

Martian microbes can survive being blasted into space by a large asteroid strike

Some bacteria can take a punch that would crush a submarine. In a new set of impact tests, one desert microbe, Deinococcus radiodurans, survived brief pressure spikes that could occur when rock gets blasted off Mars by a large asteroid strike. The work, published today in PNAS Nexus, adds experimental weight to a long-running idea in astrobiology: that life might sometimes hitch a ride between planets on chunks of ejecta. The pressures involved are hard to picture. The team pushed the bacteria to as much as 3 gigapascals, which they describe as about 30,000 times atmospheric pressure. In their setup, the cells sat in a thin, moist layer between steel plates, then took a hit from a third plate fired from a gas gun. At 1.4 GPa, survival stayed around 95% across three tests. By 2.4 GPa, survival dropped but was still about 60%. At 2.9 GPa, the group could not pin down a precise number, but survival was under 10%. Those figures sit far above what many earlier impact experiments have reported for other …