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| Mars |
Mars is one of the planets of the Solar system. It is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury. The name Mars has been derived from the name of the Roman God of war 'Mars' and is often referred to as the 'Red Planet'.The name 'Red Planet', too, has a significance as it refers to the effect of Iron Oxide which is present on the Mar's surface that gives the planet its signature red color.This color is what makes it so distinctive among the astronomical bodies visible to the naked eye. It is a terrestrial planet with a very thin atmosphere, and its surface consists of the impact crators like the Moon, as well as the valleys, deserts and polar ice caps as on the Earth.
When it comes to the duration of the days and nights, it is comparable to that of the Earth. The seasons also resemble those of Earth, because the rotational period as well as the tilt of the rotational axis relative to the ecliptic plane are similar.
Mars bears the Olympus Mons, which is the largest volcano and the highest mountain known in the Solar System. The smooth Borealis basin in the northern hemisphere of this planet covers 40% of the planet and may be a giant impact feature.
Mars' Natural Satellites or Moons
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| Phobos(left) and Deimos(right) |
Mars has two moons, namely, Phobos and Deimos. Both of them are small in size and irregularly shaped. According to space researchers, these may be captured asteroids, similar to 5261 Eureka, a Mars trojan.
Phobos is the innermost and larger of the two natural satellites of Mars. It is a small, irregularly shaped object with a mean radius of 11 km (7 mi) and is seven times as massive as the outer moon, Deimos. Phobos is named after the Greek god Phobos, a son of Ares (Mars) and Aphrodite (Venus) and the personification of fear (cf. phobia).
Phobos orbits 6,000 km (3,700 mi) from the Martian surface, closer to its primary body than any other known planetary moon. It is so close to the planet, that it orbits Mars much faster than Mars rotates, and completes an orbit just in 7 hours and 39 minutes. As a result, from the surface of Mars it appears to rise in the west, move across the sky in 4 hours and 15 minutes or less, and set in the east, twice each Martian day.
Deimos is the smaller and outermost of the two natural satellites of the planet Mars. Deimos has a mean radius of 6.2 km (3.9 mi) and takes 30.3 hours to orbit Mars. Deimos is 23,460 km (14,580 mi) from Mars, much further than Mars's other moon, Phobos. It is named for Deimos who in Greek mythology is the twin brother of Phobos, and personifies terror.
Internal Structure of Mars
Like Earth, Mars has differentiated into a dense metallic core overlaid by less dense materials. Current models of its interior imply a core with a radius of about 1,794 kilometers (1,115mi), consisting primarily of iron and nickel with about 16–17% sulfur. This iron(II) sulfide core is thought to be twice as rich in lighter elements as Earth's.
The core is surrounded by a silicate mantle that formed many of the tectonic and volcanic features on the planet, but it appears to be dormant. Besides silicon and oxygen, the most abundant elements in the Martian crust are iron, magnesium, aluminum, calcium, and potassium. The average thickness of the planet's crust is about 50 km (31 mi), with a maximum thickness of 125 km (78 mi). Earth's crust averages 40 km (25 mi).
Mars is seismically active, with InSight recording over 450 marsquakes and related events in 2019.
Facts about Mars
Here are some interesting facts about Mars that you should know:
Mars is the home of the tallest mountain, the Olympus Mons, in the solar system.
Mars' landmass is approximately equal to that of the Earth.
Even though Mars has only 15% of the Earth’s volume and just over 10% of the Earth’s mass, around two thirds of the Earth’s surface is covered in water. Martian surface gravity is only 37% of the Earth’s (meaning you could leap nearly three times higher on Mars).
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| Olympus Mons |
Olympus Mons, a shield volcano, is 21km high and 600km in diameter. Despite having formed over billions of years, evidence from volcanic lava flows is so recent many scientists believe it could still be active.
Out of several missions to panet Mars from the Earth, only 18 have been successful.
As of September 2014 there have been 40 missions to Mars, including orbiters, landers and rovers but not counting flybys. The most recent arrivals include the Mars Curiosity mission in 2012, the MAVEN mission, which arrived on September 22, 2014, followed by the Indian Space Research Organization’s MOM Mangalyaan orbiter, which arrived on September 24, 2014. The next missions to arrive will be the European Space Agency’s ExoMars mission, comprising an orbiter, lander, and a rover, followed by NASA’s InSight robotic lander mission, slated for launch in March 2016 and a planned arrival in September, 2016.
The size of the Sun as viewed from Mars is roughly half of the size as viewed from the Earth.
Mars has the largest dust storms in the entire solar system.These dust storms are really intense and can last for months and cover the entire planet.
The seasons are also extreme as its oval- shaped orbital path around the Sun is more elongated than most other planets in the solar system.
At the closest point to the Sun, the Martian southern hemisphere leans towards the Sun, thus, causing a short, intensely hot summer, while the northern hemisphere endures a brief, cold winter: at its farthest point from the Sun, the Martian northern hemisphere leans towards the Sun, causing a long, mild summer, while the southern hemisphere endures a lengthy, cold winter.
Like the Romans, the ancient Greeks also called the planet by the name Ares, after their God of war, associating the planet’s blood-red colour with Mars, their own god of war. The other ancient cultures too, focused on colour – according to China’s astronomers it was ‘the fire star’, whilst Egyptian priests called on ‘Her Desher’, or ‘the red one’.
Till now, numerous pieces of Mars have fallen to the Earth. Scientists have found tiny traces of Martian atmosphere within meteorites violently ejected from Mars, then orbiting the solar system amongst galactic debris for millions of years, before crash landing on Earth. This allowed scientists to begin studying Mars prior to launching space missions.
One day Mars will have a ring. In the next 20-40 million years Mars’ largest moon Phobos is expected to torn apart by gravitational forces leading to the creation of a ring that could last up to 100 million years.
There are signs of liquid water on Mars. For years Mars has been known to have water in the form of ice. The first signs of trickling water are dark stripes or stains on crater wall and cliffs seen in satellite images. Due to Mars’ atmosphere this water would have to be salty to prevent it from freezing or vaporising, as dissolved salt lowers the freezing point of water. The presence of water on the planet may also indicate the presence of life.
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| Martian Cliffs |
There are several investigations which are assessing the past habitability of Mars, as well as the possibility of extant life. Astrobiology missions are planned, including the Perseverance and Rosalind Franklin rovers.
Due to very low atmospheric pressure, liquid water cannot exist on the surface of Mars. The atmospheric pressure on Mars is less than even 1% of the atmospheric pressure on Earth, except at the lowest elevations for short periods. The two polar ice caps on the planet appear to consist largely of water. Studies have revealed that the volume of water ice in the south polar ice cap, if melted, would be sufficient to cover the planetary surface to a depth of 11 meters or 36 feet.
In November 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region on the planet. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior.
Mars Explorations
The Mariner 4 launched by NASA on November 28, 1964, was the first spacecraft to visit Mars, making its closest approach to the planet on July 15, 1965. Mariner 4 detected the weak Martian radiation belt, measured at about 0.1% that of Earth and captured the first images of another planet from deep space.
On July 20, 1976, Viking 1 performed the first successful landing on the Martian surface. The Soviet Mars 3 spacecraft achieved a soft landing in December 1971 but contact with its lander was lost seconds after touchdown.
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| Viking spacecraft |
On July 4, 1997, the Mars Pathfinder spacecraft landed on Mars and on July 5 released its rover, Sojourner, the first robotic rover to operate on Mars.
Pathfinder was followed by the Mars Exploration Rovers, Spirit and Opportunity, which landed on Mars in January 2004 and operated until March 22, 2010 and June 10, 2018, respectively. The Mars Express orbiter, the first European Space Agency spacecraft to visit Mars, arrived in orbit on December 25, 2003.
On September 24, 2014, the Indian Space Research Organization became the fourth space agency to visit Mars, when its maiden interplanetary mission, the Mars Orbiter Mission spacecraft, arrived in orbit.
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