NASA’s robotic lander InSight has just given us a first look deep into a planet other than Earth.
More than two years after launch, seismic data collected by InSight gave researchers a clue as to how Mars formed, how it evolved over 4.6 billion years, and how it differs from Earth. A set of three new studies has been published Sciencee this week, suggests that Mars has a thicker crust than expected, as well as a molten liquid core that is larger than we thought.
In the early days of the solar system, Mars and Earth were quite similar, each with an ocean cover covering the surface. But over the next 4 billion years, Earth became temperate and perfect for life, while Mars lost its atmosphere and water and became the barren desolation we know today. Learning more about what Mars is like on the inside could help us understand why the two planets had such different destinies.
“By leaving [a] a cartoonish understanding of what the interior of Mars looks like by putting real numbers on it, ”he said Mark Panning, a project scientist for the InSight mission, during a NASA press conference, “we are able to really expand the family tree of understanding how these rocky planets form and how they are similar and how they differ.”
Since InSight landed on Mars in 2018, its seisometer, located on the planet’s surface, has recorded more than a thousand different earthquakes. Most are so small that they would be invisible to someone standing on the surface of Mars. But a few were big enough to help the team see for the first time what was going on below.
Marsquakes create seismic waves that the seismometer detects. The researchers created a 3D map of Mars using data from two different types of seismic waves: shear and pressure waves. Shear waves, which can only pass through solid matter, bounce off the surface of the planet.
Pressure waves are faster and can pass through solids, liquids and gases. Measuring the differences between the arrival times of these waves allowed researchers to find earthquakes and gave clues about the composition of the interior.
One team, led Simon St.Ahquotes, a seismologist from ETH Zurich, used data generated from 11 major earthquakes to study the planet ‘s core. From the way the seismic waves bounced off the core, they concluded that it was made of liquid nickel-iron and was far larger than previously estimated (between 2230 and 2320 miles wide) and probably less dense.