Gravitation is one of the fundamental forces of nature, along with the weak nuclear force, the strong nuclear force and the electromagnetic force. Gravity is characteristic of bodies that have mass. Since Mars has it, obviously there is gravity there.
the force of gravity between two bodies makes them attract each other. It is proportional to the mass of the two bodies, the constant of proportionality being the universal gravitational constant, G, and it is inversely proportional to the square of the distance which separates them. In the case of the Earth, since it has a mass of six quadrillion kilos, for a person with a mass of 70 kilos, gravitational force it would be something over 380 newtons, which would be its weight. Colloquially, we tend to use the unit of mass (kilogram) to denote weight, which is not strictly correct.
On Mars, because its mass is considerably less than that of Earth, its gravity is also less, about a third of that of our planet. Something similar happens with the Moon, whose gravity is 16% that of Earth.
Surely you remember images of astronauts who reached the moon, in which they made very large leaps. These jumps are possible due to the difference in mass between the satellite and the planet. In other words, on the Moon or on Mars, we weigh much less than on Earth. On the Moon, a sixteenth part, and on Mars, a third part.
The solar system is composed, in its zone closest to the Sun, of the planets that we call rocky: Mercury, Venus, Earth and Mars. And in the furthest zone, by the gas giants: Jupiter, Saturn, Uranus and Neptune. Among rocks, Mercury has a gravity similar to that of Mars and Venus closer to that of Earth. And among the giants, Jupiter has a little more than twice the gravity of Earth, Saturn has more or less that of Earth, Uranus a little less and Neptune a little more. As I explained to you at the beginning, gravity is related to mass. These planets are much larger than Earth, but since they are gaseous, their density is much lower than that of rocky planets and therefore their gravity is also much lower.
The Sun is the most massive element in the solar system.. Its mass is more than 300,000 times that of the Earth. Therefore, its gravity is the greatest and causes the rest of the bodies of the system to orbit around it.
If we go back to Mars, it is a planet very similar to Earth and yet he aged much faster. It is about 227 million kilometers from the Sun, while the Earth is only 150 million kilometers. This additional distance, and the fact that it is a little smaller than ours, caused it to lose its atmosphere and its magnetic field, essential to life because it serves as a screen against solar radiation. These characteristics have left the planet as we know it, with this desert aspect. But it is also very interesting because it has, for example, the most impressive volcanic fields in the solar system. Mount Olympus, which is a volcano and the highest mountain on Mars and the entire solar system, is 25 kilometers high, much higher than Everest.
As for the two satellites of Mars, Phobos is 6,000 kilometers from the planet and Deimos 20,000 kilometers. They are much smaller than the Moon, which is over 3,000 km in diameter. Phobos is about 27 kilometers away and Deimos 15 kilometers away. As a little challenge, can you calculate what your weight would be on Deimos?
Marina Diaz Michelena She is the head of the space magnetism field of the National Institute of Aerospace Technology (INTA).
Question emailed byManuel Hernández
Coordination and writing:victory bull
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