A storm of cosmic impacts may have ended relatively early on Mars, suggesting that the Red Planet had habitable longer than scientists previously thought, a new study finds.
The early days of the solar system often saw giant collisions between the newborn planets and roaming pieces of rock. Left over from planetary formation, these chunks would go on to become the asteroids. Previous research suggested that the Earth's aero-size rock called Theia, coalesced to form the moon.
Prior work thus suggested that the solar system's gas giant planets migrated to their current places around the world Sun, their gravitational pulls may have been a final barrage of rocks at the World's Solar System, a violent epoch about 3.8 billion to 4 billion years ago dubbed the Late Heavy Bombardment.
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Knowing how much pummeling Earth and Mars experienced during those times could have been lighted. Now, after analyzing the oldest known sample of planetary crust in the solar system, researchers said they were late in the bombardment.
The scientists analyzed mineral grains from meteorites that crash in the Sahara Desert. Desmond Moser, a geochronologist at the University of Western Ontario, Canada.
Previous research found that meteorites possess the oldest known samples of Mars.
"Little bits of rock in the meteorites are the oldest known pieces of planetary crust in the solar system," Moser told Space.com.
Specifically, in the near future, the grains of zircon and other minerals were found to be very high the Red Planet.
"We know that Mars has weird differences between its hemispheres when it comes to the age and thickness of the crust," Moser said. "Back in the '80s, 1
Cosmic impacts generate high pressures and temperatures. Using electron microscopy and atom-sample tomography, the researchers found that nearly all of the ancient mineral grains within the Martian meteorites had the features one would expect from a cosmic impact's shock waves. In contrast, more than 80% of all mineral grains from impacted areas on Earth and the moon possess these shock features.
As such, the researchers suggested that any cataclysmic impacts on Mars ended after the ancient minerals in the meteorites formed, which happened to nearly 4.48 billion years ago. Moreover, it was proposed that it would not be late in the future.
All in all, Moser and his colleagues proposed that there was no late heavy bombardment that sterilized the early planets. If this is true, habitable pressures and temperatures may have developed by 4.2 billion years ago on both Earth and Mars.
Future Research on Mars Research.
"This may point out good samples from Mars – if not in the first missions, then other missions," Moser said.
The scientists will find their findings online June 24 in the journal Nature Geoscience.