On other planets, why it occurs, what it is needed for, as well as its effect on various organisms.

Space

Many centuries have passed since then, but alas, interplanetary flights, and especially flights to other stars, are still impossible. And the only extraterrestrial object that researchers have visited is the Moon. But already at the beginning of the 20th century, scientists knew that the force of gravity on other planets is different from ours. But why? What is it, why does it arise and can it be destructive? We will look at these questions.

A little physics

He also developed a theory according to which any two objects experience a mutual force of attraction. On the scale of space and the Universe as a whole, this phenomenon manifests itself very clearly. The most striking example is our planet and the Moon, which, thanks to gravity, revolves around the Earth. We see the manifestation of gravity in Everyday life, we just got used to it and don’t pay attention to it at all. This is the so-called It is because of it that we do not soar in the air, but walk calmly on the ground. It also helps keep our atmosphere from gradually evaporating into space. For us it is conventionally 1 G, but what is the force of gravity on other planets?

Mars

Mars is most similar in physical characteristics to our planet. Of course, living there is problematic due to the lack of air and water, but it is located in the so-called habitable zone. True, very conditional. It does not have the terrifying heat like on Venus, centuries-old storms like on Jupiter, and absolute cold like on Titan. And scientists over the past decades have not given up trying to come up with methods for terraforming it, creating conditions suitable for life without spacesuits. However, what is the phenomenon of gravity on Mars? It is 0.38 g from Earth, which is about half as much. This means that on the red planet you can gallop and jump much higher than on Earth, and all the weights will also weigh much less. And this is quite enough to retain not only its current, “frail” and liquid atmosphere, but also a much denser one.

True, it’s too early to talk about terraformation, because first you need to at least just land on it and establish constant and reliable flights. But still, the gravity on Mars is quite suitable for future settlers.

Venus

Another planet closest to us (besides the Moon) is Venus. This is a world with monstrous conditions and an incredibly dense atmosphere, beyond which for a long time no one succeeded. Its presence, by the way, was discovered by none other than Mikhail Lomonosov.

The atmosphere is responsible for the greenhouse effect and the terrifying average surface temperature of 467 degrees Celsius! Sulfuric acid precipitation constantly falls on the planet and lakes of liquid tin boil. Such an inhospitable gravity is 0.904 G from the earth's, which is almost identical.

It is also a candidate for terraforming, and its surface was first reached by a Soviet research station on August 17, 1970.

Jupiter

Another planet of the solar system. More precisely, a gas giant consisting mainly of hydrogen, which becomes liquid closer to the surface due to the monstrous pressure. According to calculations, by the way, it is quite possible that one day it will flare up in its depths and we will have two suns. But if this happens, then, to put it mildly, it will not happen soon, so there is no need to worry. The gravity on Jupiter is 2.535 g relative to Earth.

Moon

As already mentioned, the only object in our system (other than the Earth) where people have been is the Moon. True, debate still rages over whether those landings were reality or a hoax. However, due to its low mass, the surface gravity is only 0.165 g of Earth's.

The influence of gravity on living organisms

The force of gravity also has various effects on living beings. Simply put, when other habitable worlds are discovered, we will see that their inhabitants differ greatly from each other depending on the mass of their planets. For example, if the Moon were inhabited, it would be inhabited by very tall and fragile creatures, and vice versa, on a planet with the mass of Jupiter, the inhabitants would be very short, strong and massive. Otherwise, you simply cannot survive on weak limbs in such conditions, no matter how hard you try.

The force of gravity will play important role and during the future colonization of the same Mars. According to the laws of biology, if you don’t use something, it gradually atrophies. Astronauts from the ISS on Earth are greeted with chairs on wheels, since in weightlessness their muscles are used very little, and even regular strength training does not help. So the offspring of colonists on other planets will be at least taller and physically weaker than their ancestors.

So we figured out what the gravity is on other planets.

Gravity on Mars is much lower than on Earth, 62% lower to be precise. This means that Martian gravity is 38% of Earth's. A person weighing 100 kg would weigh 38 kg on Mars.

Gravity

Mars smaller than Earth and this determines the force of gravity on the planet. Newton used the law of gravity to describe how gravity works, but he only described part of the phenomenon. Einstein stated that gravity is simply the curvature of space-time that is created by the mass of an object.

The quantum physics community has proposed a theoretical particle called the “graviton” that creates gravity, so that we now have a modern understanding of gravity, but this phenomenon is still shrouded in mystery and is an obstacle to creating a universal theory of all interactions in the Universe.

Negative aspects of low gravity

It is known that people suffer from bone loss in low gravity, so when exploring planets such as Mars, the long-term effects of low gravity on the body must be taken into account and Scientific research concerning the influence of low gravity.

Overcoming the consequences of low gravity may be the starting point for human exploration of other planets.


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People have dreamed of traveling to the stars since ancient times, starting from the time when the first astronomers examined other planets of our system and their satellites through primitive telescopes. Many centuries have passed since then, but alas, interplanetary flights, and especially flights to other stars, are still impossible. And the only extraterrestrial object that researchers have visited is the Moon.

We know that Gravity is the force with which the Earth attracts various bodies.

The force of gravity is always directed towards the center of the planet. The force of gravity imparts acceleration to the body, which is called the acceleration of gravity and is numerically equal to 9.8 m/s 2. This means that any body, regardless of its mass, in free fall (without air resistance) changes its speed for each second of fall by 9.8 m/s.

Using the formula to find the acceleration of gravity

The mass of the planets M and their radius R are known thanks to astronomical observations and complex calculations.

and G is the gravitational constant (6.6742 10 -11 m 3 s -2 kg -1).

If we apply this formula to calculate gravitational acceleration on the surface of the Earth (mass M = 5.9736 1024 kg, radius R = 6.371 106 m), we get g=6.6742 * 10 *5.9736 / 6.371*6.371 = 9.822 m/s 2

The standard (“normal”) value adopted when constructing systems of units is g = 9.80665 m/s 2 , and in technical calculations they usually take g = 9.81 m/s 2 .

The standard value of g has been defined as the "average" in some sense acceleration due to gravity on Earth, approximately equal to the acceleration due to gravity at latitude 45.5° at sea level.

Due to gravity towards the Earth, water flows in rivers. A man jumps and falls to the Earth because the Earth attracts him. The Earth attracts all bodies to itself: the Moon, the water of the seas and oceans, houses, satellites, etc. Thanks to the force of gravity, the appearance of our planet is constantly changing. Avalanches come down from the mountains, glaciers move, rockfalls occur, rain falls, and rivers flow from the hills to the plains.

All living beings on earth feel its attraction. Plants also “feel” the action and direction of gravity, which is why the main root always grows downward, towards the center of the earth, and the stem always grows upward.

The Earth and all the other planets moving around the Sun are attracted to it and to each other. Not only does the Earth attract bodies to itself, but these bodies also attract the Earth to themselves. They attract each other and all bodies on Earth. For example, the attraction from the Moon causes ebbs and flows of water on Earth, huge masses of which rise in the oceans and seas twice a day to a height of several meters. They attract each other and all bodies on Earth. Therefore, THE MUTUAL ATTRACTION OF ALL BODIES IN THE UNIVERSE IS CALLED UNIVERSAL GRAVITY.

To determine the force of gravity acting on a body of any mass, it is necessary to multiply the acceleration of gravity by the mass of this body.

F = g * m,

where m is the mass of the body, g is the acceleration of free fall.

The formula shows that the value of gravity increases with increasing body weight. It is also clear that the force of gravity also depends on the magnitude of the acceleration of gravity. This means we can conclude: for a body of constant mass, the value of the force of gravity changes with a change in the acceleration of gravity.

Using the formula for finding the acceleration of gravity g=GM/R 2

We can calculate g values on the surface of any planet. The mass of the planets M and their radius R are known thanks to astronomical observations and complex calculations. where G is the gravitational constant (6.6742 10 -11 m 3 s -2 kg -1).

Planets have long been divided by scientists into two groups. The first is the terrestrial planets: Mercury, Venus, Earth, Mars, and more recently Pluto. They are characterized by relatively small sizes, a small number of satellites and a solid state. The remaining ones are Jupiter, Saturn, Uranus, Neptune - giant planets consisting of hydrogen and helium gas. They all move around the Sun in elliptical orbits, deviating from a given trajectory if a neighboring planet passes nearby.

Our “first space station” is Mars. How much will a person weigh on Mars? It is not difficult to make such a calculation. To do this, you need to know the mass and radius of Mars.

As is known, the mass of the “red planet” is 9.31 times less than the mass of the Earth, and its radius is 1.88 times less than the radius of the globe. Therefore, due to the action of the first factor, the gravity on the surface of Mars should be 9.31 times less, and due to the second, 3.53 times greater than ours (1.88 * 1.88 = 3.53 ). Ultimately, it constitutes a little more than 1/3 of the Earth's gravity there (3.53: 9.31 = 0.38). It is 0.38 g from the earth's, which is about half as much. This means that on the red planet you can gallop and jump much higher than on Earth, and all the weights will also weigh much less. In the same way, you can determine the gravity stress on any celestial body.

Now let's determine the gravity stress on the Moon. The mass of the Moon, as we know, is 81 times less than the mass of the Earth. If the Earth had such a small mass, then the gravity on its surface would be 81 times weaker than it is now. But according to Newton's law, the ball attracts as if all its mass is concentrated in the center. The center of the Earth is located at a distance of the Earth's radius from its surface, the center of the Moon is at a distance of the lunar radius. But the lunar radius is 27/100 of the earth’s, and by decreasing the distance by 100/27 times, the force of attraction increases by (100/27) 2 times. This means that the final gravity stress on the surface of the Moon is

100 2 / 27 2 * 81 = 1 / 6 earthly

It is curious that if water existed on the Moon, a swimmer would feel the same way in a lunar pond as on Earth. Its weight would decrease six times, but the weight of the water it displaces would decrease by the same amount; the ratio between them would be the same as on Earth, and the swimmer would plunge into the water of the Moon exactly the same amount as he dives here.

acceleration of free fall on the surface of some celestial bodies, m/s 2

Sun 273.1

Mercury 3.68-3.74

Venus 8.88

Earth 9.81

Moon 1.62

Ceres 0.27

Mars 3.86

Jupiter 23.95

Saturn 10.44

Uranium 8.86

Neptune 11.09

Pluto 0.61

As can be seen from the table, an almost identical value of the acceleration due to gravity is present on Venus and is 0.906 from Earth.

Now let’s agree that on Earth an astronaut-traveler weighs exactly 70 kg. Then for other planets we obtain the following weight values (the planets are arranged in ascending order of weight):

But on the Sun, gravity (attraction) is 28 times stronger than on Earth. The human body would weigh 20,000 N there and would be instantly crushed by its own weight.

If we have to travel in space through the planets of the solar system, then we need to be prepared for the fact that our weight will change. The force of gravity also has various effects on living beings. Simply put, when other habitable worlds are discovered, we will see that their inhabitants differ greatly from each other depending on the mass of their planets. For example, if the Moon were inhabited, it would be inhabited by very tall and fragile creatures, and vice versa, on a planet with the mass of Jupiter, the inhabitants would be very short, strong and massive. Otherwise, you simply cannot survive on weak limbs in such conditions, no matter how hard you try. The force of gravity will play an important role in the future colonization of the same Mars.

Description of the presentation by individual slides:

1 slide

Slide description:

Gravity on other planets. MAOU "Lyceum No. 8" Presentation: Vladislava Gileva, Ksenia Osipova. Head: Olga Valerievna Goldobina.

2 slide

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Target. Learn more about the force of attraction and gravity. Find out on which planet a person is heaviest, and on which one it is easiest!?

3 slide

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Force of attraction (force of gravity). Let's imagine that we are going on a journey through the solar system. What is the gravity on other planets? On which ones will we be lighter than on Earth, and on which ones will we be heavier? While we have not yet left the Earth, let’s do the following experiment: mentally descend to one of the Earth’s poles, and then imagine that we have been transported to the equator. I wonder if our weight has changed?

4 slide

Slide description:

It is known that the weight of any body is determined by the force of attraction (gravity). It is directly proportional to the mass of the planet and inversely proportional to the square of its radius (we first learned about this from a school physics textbook). Consequently, if our Earth were strictly spherical, then the weight of each object moving along its surface would remain unchanged. Force of attraction (force of gravity).

5 slide

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Where are we easier??? But the Earth is not a sphere. The equatorial radius of the Earth is 21 km longer than the polar radius. It turns out that strength gravity acts at the equator as if from afar. That is why the weight of the same body in different places on the Earth is not the same. Objects should be heaviest at the earth's poles and lightest at the equator. Here they become 1/190 lighter than their weight at the poles.

6 slide

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A slight decrease in the weight of objects at the equator also occurs due to the centrifugal force arising from the rotation of the Earth. Thus, the weight of an adult arriving from high polar latitudes to the equator will decrease by a total of about 0.5 kg.

7 slide

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It should be noted that for the giant planets the weight values are given at the level of the upper cloud layer, and not at the level of the solid surface, as for the Earth-like planets (Mercury, Venus, Earth, Mars) and Pluto. On the surface of Venus, a person will be almost 10% lighter than on Earth. But on Mercury and Mars the weight reduction will occur by 2.6 times. As for Pluto, a person on it will be 2.5 times lighter than on the Moon, or 15.5 times lighter than in earthly conditions.

8 slide

Slide description:

Now let’s agree that on Earth an astronaut-traveler weighs exactly 70 kg. Then for the other planets we get the following weight values (the planets are arranged in increasing order of weight): Pluto: 4.5 Mercury: 26.5 Mars: 26.5 Saturn: 62.7 Uranus: 63.4 Venus: 63.4 Earth: 70 .0 Neptune:79.6 Jupiter:161.2

Slide 9

Slide description:

... As we see, the Earth, in terms of gravity, occupies an intermediate position between the giant planets. On two of them - Saturn and Uranus - the force of gravity is somewhat less than on Earth, and on the other two - Jupiter and Neptune - it is greater. True, for Jupiter and Saturn the weight is given taking into account the action of centrifugal force (they rotate quickly). The latter reduces body weight at the equator by several percent.

10 slide

Slide description:

As is known, the mass of the “red planet” is 9.31 times less than the mass of the Earth, and its radius is 1.88 times less than the radius of the globe. Therefore, due to the action of the first factor, the gravity on the surface of Mars should be 9.31 times less, and due to the second, 3.53 times greater than ours (1.88 * 1.88 = 3.53 ). Ultimately, it constitutes a little more than 1/3 of the Earth's gravity there (3.53: 9.31 = 0.38). In the same way, you can determine the gravity stress on any celestial body.

It is well known that the Earth has the shape of a sphere, flattened at the poles. Therefore, the weight of the same body (determined by the force of gravity) in different places on the planet is not the same. For example, an adult, moving from high latitudes to the equator, will “lose weight” about 0.5 kg. What is the force of gravity on other planets in the solar system?

Sir Newton's theory

One of the founding fathers of classical mechanics, the great English mathematician, physicist and astronomer Isaac Newton, while studying the movement of the Moon around our planet, formulated the Law of Universal Gravitation in 1666. According to the scientist, it is the force of gravity that underlies the movement of all bodies in space and on Earth, be it planets revolving around stars or an apple falling from branches. According to the Law, the force of attraction between two material bodies is proportional to the product of their masses and inversely proportional to the square of the distance between the bodies.

If we talk about the force of gravity on Earth and other planets or astronomical objects, then from the above it becomes clear that it is proportional to the mass of the object and inversely proportional to the square of its radius. Before we go on a space journey, let's consider the gravitational forces on our planet.

Weight and mass

A few words about physical terms. The theory of classical mechanics states that gravity arises due to the interaction of a body with a cosmic object. The force with which this body acts on the support or suspension is called the weight of the body. The unit of measurement for this quantity is newton (N). In physics, weight is denoted, like force, by the letter F and is calculated using the formula F = mg, where coefficient g is the acceleration of gravity (near the surface of our planet g = 9.81 m/s 2).

Mass is understood as a fundamental physical parameter that determines the amount of matter contained in a body and its inert properties. Traditionally measured in kilograms. Body mass is constant in every corner of our planet and even the solar system.

If the Earth had a strictly spherical shape, the weight of a certain object at different geographical latitudes of the earth's surface at sea level would be unchanged. But our planet has the shape of an ellipsoid of rotation, and the polar radius is 22 km shorter than the equatorial one. Therefore, according to the Law of Universal Gravitation, the weight of a body at the pole will be 1/190 greater than at the equator.

On the Moon and the Sun

Based on the formula, the force of gravity on other planets and astronomical bodies can be easily calculated, knowing their mass and radius. By the way, the methods and methods for determining these quantities are based on the same Newton’s Law of Universal Gravitation and Kepler’s 3rd Law.

The mass of the cosmic body closest to us - the Moon - is 81 times, and the radius is 3.7 times less than the corresponding terrestrial parameters. Thus, the weight of any body on the only natural satellite of our planet will be six times less than on Earth, while the acceleration of gravity will have a value of 1.6 m/s 2.

On the surface of our star (near the equator) this parameter has a value of 274 m/s 2 - the maximum in the Solar System. Here the gravity is 28 times greater than on Earth. For example, a person weighing 80 kg has a weight on Earth of about 800 N, on the Moon - 130 N, and on the Sun - more than 22,000 N.

In 2006, astronomers around the world agreed to believe that the Solar System includes eight planets (Pluto was classified as a dwarf planet). Conventionally, they are divided into two categories:

Terrestrial group (from Mercury to Mars).
Giants (from Jupiter to Neptune).

Determination of gravity on other planets is carried out according to the same principle as for the Moon.

At the center of the solar system

Space objects belonging to the first group are located inside the orbit of the asteroid belt. These planets are characterized by the following structure:

The central region is a hot and heavy core consisting of iron and nickel.
The mantle, most of which consists of ultramafic igneous rocks.
Crust consisting of silicates (exception: Mercury). Due to the rarefied atmosphere, its upper layer is heavily destroyed by meteorites).

Some astronomical parameters and gravity on other planets are briefly reflected in the table.

Based on the data in the table, we can determine that the force of gravity on the surface of Mercury and Mars is 2.6 times less than on Earth, and on Venus the weight of an astronaut will be only 1/10th less than on Earth.

Giants and dwarfs

The giant planets, or outer planets, are located beyond the orbit of the Main Asteroid Belt. At the base of each of these bodies is a small rock core, covered with a huge gaseous mass, consisting mainly of ammonia, methane and hydrogen. Giants have short periods of revolution around their axis (from 9 to 17 hours), and when determining gravitational parameters it is necessary to take into account the action of centrifugal forces.

The body weight on Jupiter and Neptune will be greater than on Earth, but on other planets the gravity force is slightly less than Earth’s. These objects do not have a solid or liquid surface, so calculations are carried out for the boundary of the upper cloud layer (see table).

Giant planets

	Orbital radius (million km)	Radius (thousand km)	Weight (kg)	Acceleration of freedom drop g (m/s 2)	Astronaut weight (N)
Jupiter	778	71	1.9×10 27	23,95	1677
Saturn	1429	60	5.7×10 26	10,44	730
Uranus	2871	26	8.7×10 25	8,86	620
Neptune	4504	25	1.0×10 26	11,09	776

(Note: Saturn data in many sources (digital and print) is very inconsistent).

In conclusion, a few interesting facts that give a clear idea of what gravity is on other planets. The only celestial body visited by representatives of humanity is the Moon. According to the recollections of American astronaut Neil Armstrong, a heavy protective suit did not prevent him and his colleagues from easily jumping to a height of up to two meters - from the surface to the third step of the lunar module ladder. On our planet, the same effort only resulted in a jump of 30-35 cm.

There are several other dwarf planets orbiting the Sun. The mass of one of the largest - Ceres - is 7.5 thousand times less, and the radius is two dozen times less than that of Earth. The force of gravity on it is so weak that an astronaut could easily move a load weighing about 2 tons, and having pushed off from the surface of the “dwarf”, he would simply fly into outer space.

Weight loss