NASA’s InSight lander has “heard” and detected the vibrations of four space rocks as they impacted Mars over the past two years.
Not only are these the first impacts recorded by the spacecraft’s seismometer since InSight landed on the Red Planet in 2018, they are also the first time seismic and acoustic waves from an impact have been detected on Mars.
The US space agency has released a recording of one of the Mars meteorite impacts, in which a distinctive “bloop” sound is heard three times as the space rock enters the atmosphere, explodes into pieces, and hits the surface.
The impacts ranged from 53 to 180 miles (85 to 290 kilometers) from the stationary lander’s position in a region of Mars called Elysium Planitia, a smooth plain north of the planet’s equator.
The first of the four meteoroids – the term used for space rocks before they hit the ground – made the most dramatic appearance.
NASA’s InSight lander has “heard” and detected the vibrations of four space rocks as they impacted Mars over the past two years (pictured).
Not only are these the first impacts recorded by the spacecraft’s seismometer since InSight landed on the Red Planet in 2018, they are also the first time seismic and acoustic waves from an impact have been detected on Mars
EXPLAINING: THE DIFFERENCE BETWEEN AN ASTEROID, METEORITE AND OTHER SPACE ROCKS
An asteroid is a large boulder left over from collisions or the early solar system. Most are located between Mars and Jupiter in the Main Belt.
A comet is a rock covered with ice, methane, and other compounds. Their orbits take them much further out of the solar system.
Astronomers call a meteor a flash of light in the atmosphere when debris burns up.
This debris itself is called a meteoroid. Most are so small that they evaporate in the atmosphere.
When one of these meteoroids makes it to Earth, it’s called a meteorite.
Meteors, meteoroids and meteorites usually come from asteroids and comets.
For example, when Earth passes the tail of a comet, much of the debris in the atmosphere burns up, forming a meteor shower.
It entered the red planet’s atmosphere on September 5, 2021 and exploded into at least three fragments, each leaving a crater.
NASA’s Mars Reconnaissance Orbiter then flew over the estimated impact site to confirm the location.
It used its black and white context camera to reveal three dark spots on the surface.
After locating these spots, the orbiter’s team used the High-Resolution Imaging Science Experiment (HiRISE) camera to get a close-up of the craters in color.
“After waiting three years for InSight to spot an impact, these craters looked beautiful,” said Brown University’s Ingrid Daubar, co-author of a new research paper on the discovery and a Mars impact specialist.
After sifting through previous data, scientists confirmed that three additional impacts had occurred on May 27, 2020, February 18, 2021, and August 31, 2021.
Researchers have pondered why they haven’t spotted more meteor impacts on Mars.
The Red Planet sits adjacent to the Solar System’s main asteroid belt, which provides copious amounts of space rock to scar the planet’s surface.
Because Martian atmosphere is only 1 percent as thick as Earth’s, more meteoroids pass through it without dissipating.
The InSight seismometer has already registered more than 1,300 marsquakes.
The instrument, provided by the French space agency Center National d’Études Spatiales, is so sensitive that it can detect seismic waves thousands of kilometers away.
But the September 5, 2021 event marks the first time an impact has been confirmed as the cause of such waves.
The InSight team suspects other impacts may have been masked by wind noise or seasonal changes in the atmosphere.
But now that the distinctive seismic signature of an impact on Mars has been spotted, scientists expect to be hiding even more in InSight’s nearly four-year data.
The US space agency has released a recording of one of the Mars meteorite impacts, in which a distinctive “bloop” sound is heard three times as the space rock enters the atmosphere, explodes into pieces, and hits the surface
The impacts ranged from 53 to 180 miles (85 to 290 kilometers) from the stationary lander’s position in a region of Mars called Elysium Planitia, a smooth plain north of the planet’s equator
Seismic data offer several clues that will help researchers better understand the Red Planet.
Most marsquakes are caused by subsurface rocks fractured by heat and pressure. Studying how the resulting seismic waves change as they travel through different materials offers scientists a way to study the crust, mantle and core of Mars.
The four meteorite impacts confirmed so far produced small tremors with a magnitude of no more than 2.0.
These smaller tremors offer scientists only a glimpse of Mars’ crust, while seismic signals from larger tremors, such as the magnitude 5 event in May 2022, can also reveal details about the planet’s mantle and core.
But the implications will be crucial in refining the Mars timeline.
Seismic data offer several clues that will help researchers better understand the Red Planet
“Impacts are the clocks of the solar system,” said the study’s lead author, Raphael Garcia of the Institut Supérieur de l’Aéronautique et de l’Espace in Toulouse, France.
“We need to know the impact rate today to estimate the age of different surfaces.”
Scientists can estimate the age of a planet’s surface by counting its impact craters — the more they see, the older the surface.
InSight data can be used in combination with orbital imagery to reconstruct a meteorite’s trajectory and the magnitude of its shock wave.
Each meteoroid creates a shockwave when it hits the atmosphere and an explosion when it hits the ground. These events send sound waves through the atmosphere.
The larger the explosion, the more this sound wave tilts the ground when it reaches InSight.
The lander’s seismometer is sensitive enough to measure how much the ground tilts during such an event and in which direction.
“We’re learning more about the impact process itself,” Garcia said. “We can now associate different crater sizes with specific seismic and acoustic waves.”
The new paper was published in the journal Nature Geoscience.
WHAT ARE SOME OF THE KEY FEATURES ON MARS?
The Mars rover Curiosity was originally launched on November 26, 2011 from Cape Canaveral, a US Air Force base in Florida.
In late January 2018, the Curiosity team on Earth received numerous new images from the rover through a record-breaking relay by Nasa’s Maven orbiter, exceeding one gigabit of data from Mars during a single relay session for the first time in history.
NASA’s Jet Propulsion Laboratory in Pasadena, California, released this image as a single panoramic image that gives an overview of the rover’s path along the outer rim of the crater.
The image shows a number of key features the rover discovered during its travels. These included:
Darwin
– Darwin is an impact crater with a diameter of about 176 km.
– It was first spotted by an orbiting spacecraft
– Experts believe it could reveal the internal structure and history of the levels on the floor of Gale Crater.
– It could also provide insight into past water flows and provide clues as to whether water played a role in the stratification of rocks in the region.
Bradbury Landing
– This area is Curiosity’s landing site
– It was named after the late author Ray Bradbury, who wrote several books about Mars, including The Martian Chronicles.
Yellowknife Bay
– The rocks at Yellowknife Bay record ancient lake and river deposits
– This area may have provided favorable conditions for microbial life.
– Rocks were exposed about 70 million years ago by wind erosion eroding the overlying layers
Bagnold Dunes
– The name of this dune field is a tribute to the British military engineer Ralph Bagnold (1896 to 1990) who studied how winds move sand particles from dunes on Earth.
– These dunes are actively migrating. They are the first active dunes to be explored in situ on another planet
– Researchers hope it will help us understand modern winds and aeolian processes
twin craters
– Experts believe intense underground steam explosions created these “twin” craters.
– The larger of the two craters was named Arima after a town on the island of Trinidad and the smaller crater was left unnamed.
– Both have a diameter of more than 50 km.
– The smaller crater has several offset terraces between the top of the crater wall and the floor
– Many smaller impact craters nearby suggest that there was underground water or ice on the planet in the past