Phobos and Deimos are the remains of a much larger Mars moon that was blown apart a billion years ago
Mars’s moons – Phobos and Deimos – are two fragments of what was once a much larger Mars satellite that was blown apart by a massive collision, a study finds.
The collision between the moon and a stray rock, possibly an asteroid, is thought to have occurred between one and 2.7 billion years ago and triggered a powerful explosion.
Two of the chunks from this violent explosion were trapped in Mars orbit and are what we know today as Phobos and Deimos.
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Mars’s pair of moons – Phobos and Deimos – are two fragments of what was once a much larger Mars moon blown apart by a stray asteroid. The collision is believed to have occurred between one and 2.7 billion years ago (photo, artist’s impression)
WHAT IS PHOBOS IF AND WHAT DOES THE NAME MEAN?
Named after the mythological Greek character for panic or fear
JAXA thinks Phobos may have ancient Mars Earth on the surface
- Diameter: 13.8 miles
- Turnaround time: 7.66 hours
- Distance from Mars: 3,700 miles
- Discovered: August 18, 1877
- Gets about 6.5 feet closer to Mars every hundred years
- Tidally trapped with Mars
Seismic data from NASA’s InSight mission was fed into a computer simulation to determine the historical orbits of both current moons.
“The idea was to trace the jobs and their changes back to the past,” says Dr. Amir Khan of the University of Zurich and the Institute of Geophysics at ETH Zurich.
The data showed that Phobos and Deimos would intersect at some point – indicating that they were likely in the same place and thus of the same origin.
Write in their paper, published in Nature astronomyastronomers at ETH Zurich conclude that they come from a much larger celestial satellite.
The calculations depended on estimates of the properties of the two moons.
Both moons were discovered in 1877 by the American astronomer Asaph Hall. The moons are aptly named after two twins from Greek mythology, the children of Ares (Mars) and Aphrodite (Venus).
Phobos is the Greek god of fear and panic, while Deimos is the personal god of fear and terror.
Phobos is larger, at 14 miles wide, while Deimos is only 7.5 miles in diameter and the former is closer to Mars than its smaller twin. Earth’s moon is 2,158 miles in diameter – 155 times the size of Phobos and 288 times larger than Deimos.
These little moons are also “very irregularly shaped – like potatoes,” said Amirhossein Bagheri, a PhD student at the Institute of Geophysics at ETH Zurich.
He adds, “Phobos and Deimos are more like asteroids than natural moons.”
Astronomers have been puzzled by the origin of the two moons for decades, unable to explain their unusual features.
Their irregular shape is unusual in space, with planets and moons becoming round over time due to the force of gravity exerted on them.
Another conundrum was the fact that their appearance resembles asteroids, but their orbits don’t fit this theory.
Asteroids float through space and can occasionally get stuck in a planet’s orbit.
However, when this happens, they enter and stay at a certain angle from the planet they orbit, and often have eccentric orbits that are elongated at one end.
But Phobos and Deimos orbit Mars in an almost circular orbit and are in line with the Red Planet’s equator.
To solve the mystery, the astronomers from Zurich collected data on the properties of the rocks from which the moons are made, which was created by InSight and combined it with measurements from other Mars probes.
It enabled the researchers to model a space phenomenon known as tidal forces, which states that each celestial body exerts some force on its neighbors.
For example, the Moon and Earth are in a constant tug of war, and the same is true of any lunar planet dyad.
But the scale of the tidal force depends on several factors, including the proximity, mass, and composition of the objects in the equation.
For Mars, Phobos and Deimos, the first two factors are easy to calculate, but the third is relatively unknown as no samples have ever been obtained from Mars’ moons.
Japan hopes to reach Phobos by 2025 and take samples from the surface and bring them to Earth for analysis.
Best estimates indicate that the mane is made of an extremely porous material with a very low density.
Measurements from InSight and other projects indicate that the moons have a density of about two grams per cubic centimeter. This is lighter than chalk (2.5 g / cm ^ 3) and limestone (2.7 g / cm ^ 3).
It was these data that were key to enabling the researchers to piece together the history of the moons and discover their violent origins.
The historical predictions were also used to calculate future projections of the fates of the moons.
It revealed that the ancestors of Phobos and Deimos were further from Mars than Phobos is today and probably in a similar orbit to Deimos.
Due to its proximity to Mars, Phobos is slowly getting closer to Mars and is likely to collide with Mars within 40 million years.
However, Deios will encounter a similar ending to that of Earth’s moon as it slowly drifts further away from Mars, and one day it will break free from the red planet’s orbit.
NASA shows the moment when Persistence hit Mars
The world first got a close-up of a spacecraft landing on Mars yesterday, when NASA unveiled an ‘awe-inspiring’ video beamed back to Earth by Perseverance, landing on the Red Planet on Thursday.
The video begins with the violent release of the rover’s sonic parachute along with the ejection of the heat shield and shows the moment when the overhead crane maneuver is triggered.
Perseverance is equipped with 25 cameras and two microphones all turned on during the $ 2.2 billion rover on Thursday – the audio did not record on the descent, but survived the landing, recording audio from a Martian breeze two days after the landing on the Red planet.
The camera system was able to capture the dramatic “seven minutes of terror” as Persistence endured tumultuous conditions that battered the craft as it entered the Martian atmosphere and approached the surface.
After the parachute deployed and the heat shield discarded, Perseverance was able to see the red, dusty surface of Mars for the first time as it floated toward the landing target.
Craters littering the Red Planet, along with higher distant landscape, can be seen, and the microphones picked up the sound of Martian air – first heard on Earth.
“For those wondering how to land on Mars – or why it’s so difficult – or how cool it would be to do that – look no further,” said acting NASA administrator Steve Jurczyk.
Perseverance has only just begun and has already produced some of the most iconic images in the history of space exploration. It enhances the remarkable level of engineering and precision required to build a vehicle and fly to the Red Planet. ‘
NASA has also released images of the pink-hued surface of Mars directly below Perseverance, captured with the Rover Down-Look Camera.
The surface of Mars has an orange-red color due to iron oxide or rust particles in the soil. The air on Mars often appears pink or light orange because the dust in the ground is blown by the wind on Mars into the thin atmosphere of Mars.