An ancient asteroid as huge as Rhode Island state once scorched the heavens and boiled the primal oceans of the Earth that rocked the planet for as long as half and hour, according to scientists who recently published a study in Geochemistry, Geophysics, Geosystems, a journal of the American Geophysical Union (AGU). The meteor that exploded over Russia on February 15, 2013 would seem like a tiny firecracker pop compared to the asteroid that slammed into the Earth about 3.26 billion years ago.
According to the press release from AGU, the asteroid was about three to five times larger than the one that was supposed to have killed the dinosaurs and most of Mesozoic life about 65 million years ago (K-T extinction). It slammed a crater into the planet’s crust that was about 300 miles across — 2.5 times greater than the one in the K-T extinction. The distance was greater than the distance between New York City and Washington D.C. or almost half the longitudinal width of South Africa. The seismic waves that rocked the Earth was six times more powerful than the Tohoku earthquake that shook Japan in 2011. The impact may have triggered tsunamis that were several hundred feet high, towering several times over the tall skyscrapers in Chicago or Hong Kong.
Geologist Donald Lowe from Stanford University and co-author of the study first discovered evidence of the suggested impact in the Barberton Greenstone Belt in South Africa ten years ago, which has one of the oldest rock formations in the world. It is about 62 miles long and 37 miles wide, resting just east of Johannesburg near South African and Swaziland border. When the asteroid slammed into the planet at more than 42,000 miles per hour, fissures formed, trapping some of the asteroid’s components. Over the Earth’s history, plate tectonics have erased most of the traces of the collision. However, ge0logists found spherules the size of sand particles in these fissures that had condensed from a vaporized cloud of rocks and debris that were created after the asteroid impact. These tiny spherules contain iridium, which is an element that is very common in asteroids but rare on Earth.
Lowe and his colleagues created models of the impact based on the current evidence, which revealed how big it really was for the first time and its impact on the young Earth. Researcher think that this event led to the way how plate tectonics work today. This is the first study that had mapped an asteroid impact during this part of the Earth’s history, which is also known as the Late Heavy Bombardment.
This period occurred between 4 to 3 billion years ago when the planet and its moon were pummeled with asteroids, comets, and other space debris in the early solar system, according to Space.com. The Earth then may have resembled a lot like Mordor in the Lord of the Rings trilogy, covered with rocky land surfaces, volcanoes, and primordial oceans. When the ancient asteroid slammed into the earth, the atmosphere scorched with fire and the Earth’s crust rocked and rumbled, sending a colossal amount of debris and liquified rocks that later rained onto the boiling seas.
Over a few billion years, erosion and plate tectonics separated the remains of the crater, spreading them apart like a jigsaw puzzle. Some gets buried deep in the Earth’s mantle and possibly the core; some gets trapped and preserved in the fissures, such as the ones in Barberton. Although Lowe does not know exactly where the original crater may have been, evidence in South Africa and Western Australia may provide clues to pinpoint the location. Researchers think that ground zero may be a few thousand miles away from the Barberton Greenstone Belt.
Although the Earth had numerous asteroid collisions in its near 4.6-billion-year history, it may not be last time that the planet will be boiled, scorched, and rocked like a snow globe. There are numerous asteroids in the asteroid belt and the solar system that are even bigger than the one documented in the study. According to NASA’s Jet Propulsion Laboratory (JPL), there are about 140 asteroids with a massive diameter bigger than the Rhode Island-size asteroid. Ceres, the largest one found in the asteroid belt, has a diameter of almost 600 miles. Smaller ones that could still wipe out all life on Earth include Vesta (326 miles), Antiope (120 miles), Dysona (83 miles), and Justita (53.6 miles). This ancient discovery can help scientists understand better about Earth’s early history and evolution with the possibility of providing more evidence to explain the origin of life on Earth.
By Nick Ng