All posts tagged: asteroid impacts

Chang’e-6 moon rocks reveal a 3.9-billion-year decline in asteroid impacts on the dark side of the Moon

Chang’e-6 moon rocks reveal a 3.9-billion-year decline in asteroid impacts on the dark side of the Moon

Published by Jenni Sidey

Rocks from the Moon’s far side suggest asteroid impacts slowly decreased instead of peaking in one brief catastrophe. The samples place the Apollo basin’s formation at about 4.16 billion years ago, much earlier than the proposed bombardment peak. The Moon preserves evidence erased from Earth, helping scientists study the violent conditions both worlds experienced when they were young. The Moon’s far side has kept a cleaner record of ancient violence than the hemisphere facing Earth. Tiny fragments returned by China’s Chang’e-6 mission now suggest asteroid impacts faded gradually, challenging the idea of one catastrophic spike 3.9 billion years ago. The research traces impact events across more than three billion years, from about 4.33 billion to 1.13 billion years ago. Its strongest evidence comes from rocks collected inside the Apollo basin, within the enormous South Pole-Aitken basin. Co-author Dr Fred Jourdan, from Curtin’s School of Earth and Planetary Sciences, said lunar rocks preserve evidence Earth has lost through erosion, volcanic activity and shifting tectonic plates. The published 40Ar/39Ar ages of Apollo, Luna, and meteorites, respectively. The …

Violent asteroid impacts may have helped spark life on early Earth

Violent asteroid impacts may have helped spark life on early Earth

Published by Jenni Sidey

Long before oceans teemed with life, Earth endured relentless violence. Asteroids slammed into its surface again and again, reshaping the young planet. These impacts once seemed purely destructive. New research now suggests they may have helped create the conditions needed for life to begin. Scientists at Southwest Research Institute used advanced modeling to study how early impacts altered Earth’s crust. Their findings reveal a world where collisions opened pathways for water and heat deep underground. These environments, known as hydrothermal systems, may have supported the earliest chemical steps toward life. Amanda Alexander, lead author of the study, describes the importance of the work. “This modeling is both novel and crucial for understanding the earliest environments life may have emerged from,” she said. A Violent Beginning For A Young Planet Earth formed about 4.5 billion years ago. Soon after, it entered a chaotic period marked by intense bombardment. Large space rocks struck the surface at extreme speeds. Each collision released immense energy. SwRI Institute Scientist Dr. Simone Marchi created this artistic rendering of early Earth, which …

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

Published by Jenni Sidey

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

Published by Jenni Sidey

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

Published by Jenni Sidey

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 …