Meteors Shook Mars, The exquisitely sensitive seismometer on NASA’s InSight lander dutifully recorded the burst of seismic vibrations and then dispatched the data,
The InSight scientists were busy celebrating the holidays. When they studied the tremor in detail in early January, it looked different from the more than 1,000 marsquakes that the stationary spacecraft had recorded during its mission to study the insides of the red planet for more than three and a half years. “It was clearly a seismic event, and it was a big seismic event,” said Mark Panning, the project scientist for the InSight mission. “And we were excited about it right away.” In scientific papers published Thursday, scientists using data from two NASA spacecraft reveal that the seismic event was not the cracking of rocks from the internal stresses of the red planet. Instead, it was shock waves emanating from a space rock hitting Mars. Meteors Shook Mars, The discovery will help scientists better understand what is inside Mars and serves as a reminder that just like Earth, Mars gets whacked by meteors too.
Unlike Earth, though, where meteors usually disintegrate in the atmosphere, rocks from space slam into Mars largely intact. Mars lacks plate tectonics, the sliding of pieces of the crust that shapes the surface of Earth. Meteors Shook Mars, But marsquakes occur nonetheless, driven by other tectonic stresses like the shrinking and cracking of the red planet’s crust as it cools. The largest marsquakes are modest by Earth standards. The December shaking registered as among the most powerful that had been recorded, at a magnitude of 4. But it did not occur in the tectonically active region where most of the bigger quakes have been observed. Most crucially, the Christmas Eve seismic event was the first time that surface waves vibrations traveling along the outer crust of rocks at the surface of Mars had been detected. For all of the other marsquakes, InSight’s seismometer had only observed what are known as body waves, vibrations traveling through the planet’s interior.
Source: This news is originally published by nytimes