How do asteroids move? The largest asteroids and their movement

One of the planned areas of space research at NASA is the study of asteroids. What are they planning to look for on these bare cosmic blocks, what secrets do these silent pieces of stone conceal?

Currently, scientists have studied the largest asteroids and their movement quite well. It is impossible to briefly talk about these bodies of the Solar System (more than seven hundred thousand of them have been discovered so far). Where did they come from and what are asteroids?

Planet number four and a half

Already in the eighteenth century, astronomers were relatively well aware of the scale and extent of the solar system. Researchers Titius and Bose noticed that the line of distances of planets from the sun fits into the correct mathematical sequence. There was only one place where the theory failed. The first four planets: Mercury, Venus, Earth and Mars corresponded completely to the mathematical model, and then...

Jupiter, the fifth planet, occupied the sixth place. There was another celestial body missing between Mars and Jupiter.

The planets in the solar system, not counting our star, are the largest bodies. Asteroids and their movement were discovered and systematized later. And at that moment, this failure in the sequence became a real challenge for astronomers.

The hunt for planet No. 4 ½ was not without drama and was crowned with success in 1801. The Italian scientist Piazzi congratulated earthlings on the New Year, 1801, by discovering on January 1 the first small planet, later named Ceres in honor of the ancient Greek goddess of fertility.

A failed planet or a catastrophe on a universal scale

Almost immediately after, the second asteroid Pallas was discovered. Then two more: Juno and Vesta. The region of the system in which the largest asteroids are located was gradually determined. Their movement suggested that they were all part of something big.

This is how the theory arose about the existence of the ancient planet Phaeton, rotating in an orbit located between the planets Mars and Jupiter, and destroyed as a result of some kind of cosmic cataclysm.

Ufologists also didn’t miss the chance, where would we be without them? In their opinion, the inhabitants of Phaeton visited our planet, appearing to the aborigines in the form of gods. They taught our prehistoric ancestors writing, mathematics and other sciences, and, naturally, built the ancient Egyptian pyramids.

And then Phaeton fell victim to the Phaetonians themselves, who were playing with some of their superweapons.

However, later studies, including those carried out by NASA's automatic interplanetary probes, showed that the beautiful theory, alas, is untenable.

According to modern ideas, the remnants of the protoplanetary disk matter rotate between Mars and Jupiter, which was not enough to form a full-fledged planet. And the powerful gravitational field of the giant Jupiter would not have allowed the formation of a more or less large celestial body.

Plus two small minus one big

The first asteroid discovered, Ceres, has always stood out among the rest. As it turned out later, a third of the mass of the entire asteroid belt is concentrated in it. With a diameter of about 1000 km, it is the only “inhabitant” of the belt and has a mass sufficient for hydrostatic equilibrium (formation of a spherical shape).

There is also geology due to the immersion of heavier components, and only the largest of cosmic bodies can boast of this.

Asteroids and their motion came under close study with the advent of giant reflecting telescopes; they began to be discovered at the rate of several thousand per year. And the faster their base grew, the more obvious their uniqueness in the Ceres asteroid belt became.

In 2006, an event occurred that increased the status of this planetoid. A year earlier, several trans-Neptunian objects were discovered, comparable in size to Pluto, which until then was considered the ninth planet of the solar system.

So, it was decided to deprive Pluto of the “title” of a planet. From now on, all such bodies began to be called “dwarf planets.” Ceres also fits this definition. Thus, there are two more dwarf planets in the solar family due to one full-fledged and one asteroid.

Asteroid orbits

The most “busy” movement of asteroids is concentrated, as already indicated, between Mars and Jupiter. However, the shape of the orbits of most of them differs markedly from the orbits of planets moving in almost perfect circles. So, if the second largest asteroid in the solar system, Vesta, has an orbital eccentricity of 0.089 and is constantly in the belt, then Eros, for example, moves differently.

At the highest point of the orbit, it is, as it should be, in the asteroid belt, and then, crossing the orbit of Mars, Eros rushes towards the Earth, not reaching its orbit by “some” 20 million kilometers.

The asteroid with the most elongated trajectory is considered to be 2005HC4. At the farthest point it “flies” far beyond the orbit of Mars, but at perihelion it approaches the Sun 7(!) times closer than Mercury.

Danger to Earth

There are many such cosmic “pebbles” of different sizes that cross the Earth’s orbit and, therefore, are theoretically capable of crashing into us. This is one of the reasons forcing scientists from all countries to study in detail the movement of asteroids.

Basic information about the orbits of the largest of them was obtained many decades ago. Fortunately, among them there are no candidates for a collision with our planet in the next few million years.

This, alas, cannot be said about smaller cosmic bodies measuring hundreds of meters or less. Despite the fact that the number of discovered asteroids is approaching a million, astronomers are constantly discovering more. In addition, the asteroid belt is a rather “overpopulated area” of the solar system. Their collisions with each other can easily dramatically change the orbit of a relatively small rock, like a slingshot, directing it towards one of the planets.

Treasure Planet

However, it appears that brief data on the movement of asteroids may eventually begin to appear in economic news. Recently, interest in their study is due to plans (though still very distant) for their development in the future as mineral deposits.

It is roughly estimated that the depths of Eros contain several times more rare earth metals than human civilization has mined and used throughout its history.

However, for the hypothetical development of gold and platinum deposits on the surface of a cosmic body, it is desirable that there be at least a small force of gravity there. Only the largest asteroids have this quality. And their motion and stable, almost circular orbit make, for example, Ceres and Vesta, prime candidates for exploration. It is possible that in a couple of hundred years young couples will fly to Eros on their honeymoon, and it’s not for nothing that they came up with such a name for it...

Asteroids have been known to astronomers for a long time, but the world community started talking about them seriously only after 2004, when information appeared in the media that this could have been a disaster, destroying about 25% of life on the planet. Then the trajectory of the asteroid was recalculated, everyone calmed down, but interest in asteroids and others remained. So, ?
1

Diameter is about 950 km. What this celestial body has been since its discovery (which happened, for a moment, in 1801!): a full-fledged planet, an asteroid, and since 2006 it has been considered a dwarf planet - for being the largest in the asteroid belt. Ceres is spherical in shape, which is completely uncharacteristic of asteroids; the core consists of rock, and the crust is made of minerals and water ice. The closest point of its orbit is at a distance of 263 million km from Earth, so it is unlikely that a collision should be expected - at least in the next few thousand years.

2

Its diameter is 532 km. It also forms part of the asteroid belt and is very rich in silicon - in the future it may become a source of minerals for earthlings.

3

530 km in diameter. Even though Vesta is smaller in size than previous asteroids, it is the heaviest asteroid. Its core consists of heavy metal, its crust is made of rock. Due to the characteristics of this rock, Vesta reflects 4 times more sunlight than the leader of our top - Ceres, so sometimes, once every 3-4 years, Vesta’s movements can be observed from Earth with the naked eye.

4

Its diameter is considerable - 407 km, but this asteroid is so dim that it was discovered later than the others. Hygea is a typical representative of the most common type of asteroid - with carbonaceous content. At the moment of its maximum approach to the Earth, this celestial body can be observed not through a telescope, but through binoculars.

5

Diameter – 326 km. Despite the fact that Interamnia is a very large asteroid, it still remains a very little-studied celestial body. First of all, because they belong to asteroids of the rare spectral class F, neither their exact composition nor the internal structure is known to modern science. As for Interamnia, even its exact form is unknown! Complete mysteries...

6

The diameter of this asteroid is 302.5 km, and it was discovered a long time ago - in 1858. It has a very elongated orbit, so the distance from Europa to the Sun can change very significantly (if there was life here, it would be some super-adaptive mutants!). Its density index is only slightly greater than that of water, which means that the surface of this celestial body is porous. It's like a giant pumice stone rotating in the Great Asteroid Ring.

7

Its diameter, according to various estimates, ranges from 270 to 326 km. Where does such a strange name come from? The discoverer of this asteroid, Raymond Dugan, named the celestial body he discovered after astronomy professor David Todd, but the name was remade into a “female” version - “David”, since at that time only female names were given to asteroids (and, as you may have already note, most are from Greek mythology).

8

Diameter – 232 km. This asteroid, like Europa, has a large porosity - essentially, it is a pile of rubble that is held together by gravity. Sylvia is the first triple asteroid known to us, because it has at least 2 satellites!

9

A very strange space object with dimensions of 370 × 195 × 205 and a shape that looks like either a peanut or a dumbbell, and in addition to everything, it also has its own (as yet unnamed) moon. Its origin is interesting: the fact is that Hector consists of a mixture of rock and ice. The Kuiper belt objects Pluto and its satellite Triton have this composition. This means that Hector arrived from the Kuiper Belt (the region of space beyond Pluto), most likely at the dawn of the formation of the Solar System, when the planets were actively migrating.

10

Size – according to various sources, from 248 to 270 km – is a large and rapidly rotating asteroid. It has a very high density, but this is due to its large size.
And just recently - on July 19 - asteroid UW-158 with a core containing about 100 million tons of platinum passed very close to Earth (2.4 million km, nothing for space)! Such wealth is gone... So asteroids continue to surprise us!

Judging by disaster films, asteroids can be considered the main enemies of humanity, along with viruses, zombies and irresponsible politicians. Dozens of films tell about disasters that begin on Earth after a collision with even a relatively small celestial body. An incomplete list includes tsunamis, earthquakes, climate change and other phenomena that are not very useful to humans.

The possibility of a collision between the Earth and an asteroid exists, but, fortunately, it is extremely small. Still, it is more correct to imagine the Universe in general and the Solar system in particular as empty space, in which large bodies such as planets, their satellites and asteroids are very rarely found. This fact is indicative: despite the fact that thousands of large and small celestial bodies are discovered in the space between Mars and Jupiter, spacecraft cross this zone not only without damage, but also without threatening approaches to asteroids.

The history of the discovery of asteroids in popular science literature is usually presented in a way that spares scientists. Like, Johann Titius in the 18th century calculated the pattern of the distance of planets from the Sun, and a little later his namesake Bode calculated that there should be a planet between Mars and Jupiter. Astronomers began to look for it and discovered it in 1801. From then on it all started...

In this version, everything looks natural and beautiful, but there are a number of nuances. Titius's formula turned out to be a well-chosen empirical combination. Astronomers were indeed looking for the first asteroid. Baron Xaver even created a heavenly police force for this search. Two dozen astronomers were allocated equal areas of the sky in which the machinations took place.

But it was not any of the “heavenly policemen” who discovered the future Ceres, but the Italian Giuseppe Piazza. The astronomer was not looking for anything new - he was compiling a catalog of stars, and on New Year's Eve 1801 he accidentally stumbled upon a rapidly moving point. Moreover, Piazza immediately lost his discovery, barely having time to name the new planet, as he thought, Ceres. Carl Gauss helped. Using mathematical calculations, he found the place to look for replenishment in the solar system, and Ceres was rediscovered. That is, the discovery of Piazza is to some extent similar to the discovery of America by Columbus - both were looking for the wrong thing, but the significance of these discoveries does not diminish the significance of these discoveries.

There are more asteroids

Since 1802, two parallel processes have been going on in the astronomical community. Astronomers discovered many new asteroids, while simultaneously debating their status and origin. They were proposed to be considered small planets; they even invented the precise but unsound term “Zenareids” (“located between Jupiter and Mars”). But the currently used name won. It was neutral - any body can be called an "asteroid", regardless of its relative size, origin, composition and orbit. And practical searches have led to the fact that about 300 thousand asteroids have already been discovered in the Solar System.

The largest asteroids

It is clear that in the gigantic number of discovered asteroids, the vast majority are small objects. All honors, including proper names, go to large asteroids. If we take into account the sizes, the list of the largest asteroids will be something like this:

10. Euphrosyne

The Euphrosyne asteroid, despite its proximity to Earth and its large size, is difficult to see from Earth even from the shortest distance - due to the large amount of carbon in its composition, it is very dark. The asteroid, 256 kilometers in diameter, moves in an orbit close to vertical to the ecliptic plane and completes its orbit around the Sun in 5.6 years.

Hector was discovered in 1907, but due to its great distance from Earth (it is closer to Jupiter) and low reflectivity, it could only be properly seen in the 21st century. It turned out that the asteroid with a maximum length of 370 kilometers is shaped like a bean or a dumbbell, and its two massive parts can only be connected by gravity.

It takes Hector almost 12 years to fly around the Sun. At the same time, the speed of its own rotation is close to the speed of other asteroids and is less than 7 hours.

8. Sylvia

Strictly speaking, Sylvia is not a single asteroid, but a system with two satellites - Romulus and Remus. And the main asteroid is most likely not a monolith, but small stones collected together by gravity - Sylvia’s average density is too low.

The Sylvia system rotates around the Sun in 6.5 years, and around its axis in a little longer than 5 hours. During its orbital movement, Sylvia's size can change by 10%.

7. David

This asteroid had to be slightly renamed for the sake of tradition. The American who discovered it, Raymond Dugan, gave his discovery the name David in honor of Professor David Todd. But there was a tradition of giving female names to asteroids, and the name was adjusted.

With the help of the largest telescopes at that time, located in Hawaii, they not only determined the size of Davida (at least 231 kilometers), but also saw a huge crater on the surface. It is characteristic that in the course of calculating the mass of Davida, the results gave a two-fold scatter. A year on this asteroid lasts 5.6 years, and a day is a little more than 5 hours.

6. Europe

Asteroid Europa is lighter than its colleagues in the group of large asteroids. This allowed astronomers to assume that it consists of porous substances. And because of the low shine, it is believed that these are compounds containing carbon.

The asteroid with a diameter of 302.5 kilometers rotates in an elongated orbit. The difference in distance to the Sun ranges from 413 to 512 million kilometers. A day on Europa lasts 5.6 hours, and a year lasts 5.5 Earth hours.

This asteroid still remains a big mystery. It is known that its diameter is 326 kilometers, Interamnia makes a revolution around the Sun in 5.4 years, and a day lasts almost 8 hours. However, due to its remoteness and very dark surface, astronomers have no information about the composition of the asteroid. Even general physical information was obtained not by direct observations, but during the occultation of a bright star by Interamnia.

The asteroid, named after the goddess of health, was discovered quite late - in 1849. Hygea, compared to other large asteroids, is quite far from the Earth, and its surface reflects little light.

A year on Hygiea, which has a diameter of 407 kilometers, lasts 5.5 Earth years, but a day is three hours longer than Earth years.

Pallas ranks third among asteroids in size, and second in time of discovery - Heinrich Olbers discovered it in 1802. For a long time she held second place in both categories, but after clarifications, Pallada became third.

The diameter of Pallas is 512 km. It rotates in an inclined and highly elongated orbit, so a year on it lasts more than 4.5 Earth years.

Vesta, which ranks second among asteroids, has surpassed Pallas in size quite slightly - its average diameter is 525 kilometers, and its maximum value is 573 kilometers (Vesta has a rather irregular shape).

There are many deep craters on the surface of the asteroid, including the Rheasilvia crater, the diameter of which is comparable to the diameter of Vesta itself. In the center of the crater, a mountain rises 22 kilometers high. Scientists still do not know how the asteroid survived an impact of such monstrous force.

Vesta's weight shows that its core is made of metals. Perhaps in the future the asteroid, which now revolves around the Sun at a speed of one revolution per 42 Earth months, will become a source of raw materials for Earth metallurgy.

The largest asteroid officially had this status until 2006. Ceres, discovered by Giuseppe Piazza, existed as an asteroid for 200 years and became a small planet. This is what the International Astronomical Union decided. However, with all due respect to the vote of astronomers, Ceres does not reach the planet in any way - its diameter of 950 kilometers, impressive in the company of asteroids, is almost five times smaller than Mercury, which became the smallest planet after Proton’s disqualification.

Unlike small asteroids, Ceres has an almost regular spherical shape. About a third of the asteroid consists of ice, the rest is iron ores and carbonates. A year on an asteroid revolving around the Sun between the orbits of Jupiter and Mars lasts more than 4.5 Earth years, and a day is shorter than Earth years - Ceres makes a revolution around its axis in 9 hours.

At the very beginning of the 19th century. Italian astronomer Piazzi (1746-1826) accidentally discovered the first minor planet (asteroid). She was named Ceres. Subsequently, many other small planets were discovered, forming the asteroid belt between the orbits of Mars and Jupiter.

Asteroid movement

In photographs of the starry sky taken with long exposures, they appear as light lines. More than 5,500 minor planets have been registered. The total number of asteroids should be tens of times greater. Asteroids whose orbits are established receive designations (serial numbers) and names. Some new asteroids are named after great people (1379 Lomonosov), states (1541 Estonia, 1554 Yugoslavia), observatories (1373 Cincinnati - an American observatory that is the International Asteroid Observation Center), etc.

Asteroids move around the Sun in the same direction as the large planets. Their revolutions have larger eccentricities (on average 0.15) than the orbits of large planets. Therefore, some small planets extend far beyond the asteroid belt. Some of them move beyond the orbit of Saturn at aphelion, while others approach Mars and Earth at perihelion. For example, Hermes in October 1937 passed from the Earth at a distance of 580,000 km (only one and a half times further than the Moon), and the asteroid Icarus, discovered in 1949, even moves inside the orbit of Mercury and approaches the Earth every 19 years . The last time this happened was in June 1987. Then Icarus approached the Earth at a distance of several million kilometers and was observed at many observatories. Of course, this is not the only case. It is possible, for example, that the collision of an asteroid with the Earth led to the death of dinosaurs 65 million years ago. And in March 1989, an asteroid measuring about 300 m passed from the Earth at a distance of less than 650 thousand km. Therefore, it is no coincidence that scientists have begun to develop effective methods for the timely detection and, if necessary, destruction of dangerous asteroids.

Physical characteristics of asteroids

Asteroids are not visible to the naked eye. The largest asteroid is Ceres (diameter 1000 km). In general, asteroids have diameters from several kilometers to several tens of kilometers, and most asteroids are shapeless blocks. The masses of asteroids, although different, are too small for these celestial bodies to retain an atmosphere. The total mass of all asteroids collected together is about 20 times less than the mass of the Moon. All the asteroids would make one planet with a diameter of less than 1500 km.

In recent years, it has been possible to discover satellites (!) on some asteroids. The asteroid was first photographed from a distance of only 16 thousand km on October 29, 1991, from the American spacecraft Galileo, launched on October 18, 1982 to study Jupiter. Crossing the asteroid belt, Galileo photographed the minor planet 951 - the Gaspra asteroid. This is a typical asteroid. The semimajor axis of its orbit is 2.21 AU. It turned out to be irregular in shape and may have been formed as a result of the collision of larger bodies in the asteroid belt. The photographs show craters (their diameter is 1-2 km, the consecrated part of the asteroid is 16x12 km). In the images, it is possible to discern details of the surface of the Gaspra asteroid with a size of 60-100 m.

In astronomy, an asteroid is a small celestial body that rotates in an independent elliptical orbit around the Sun. The chemical composition of asteroids is varied. Most of these celestial bodies are carbonaceous objects. However, there are also a significant number of silicon and metal asteroids in the Solar System.

Asteroid belt

In the Solar System, between the orbits of the planets Mars and Jupiter, there are a huge number of asteroids of various sizes and shapes. This cluster of celestial bodies is called the asteroid belt. This is where the largest asteroids in our system are located: Vesta, Ceres, Hygiea and Pallas. It is worth noting that the history of observation and study of asteroids began with the discovery of Ceres.

The largest asteroids

Vesta

It is the heaviest asteroid and one of the largest (second largest). The celestial body was discovered in 1807 by Heinrich Olbers. The interesting thing is that Vesta can be observed with the naked eye. The asteroid was named by Carl Gauss in honor of the ancient Roman goddess, the patroness of the family hearth.

Ceres

Ceres, named after the ancient Roman goddess of fertility, was discovered in 1801 by Giuseppe Piazzi. Initially, scientists believed that they had discovered another planet, but later determined that Ceres was an asteroid. The diameter of this celestial body is 960 km, which makes the asteroid the largest in the belt.

Hygeia

The credit for the discovery of Hygeia belongs to Annibale de Gasparis. In 1849, he discovered a large celestial body in the asteroid belt, which later received the name of the ancient Greek goddess of health and well-being.

Pallas

This asteroid was discovered a year after the discovery of Ceres, thanks to the observations of the German astronomer Heinrich Olbers. Pallas was named after the sister of the ancient Greek goddess of war, Athena.

Danger of collision with Earth

Let us note that in the past our planet was hit by 6 asteroids with a diameter of at least 10 km. This is evidenced by huge craters on the surface of the Earth in various countries. The oldest crater is 2 billion years old, the youngest is 50 thousand years old. Thus, the potential danger of an asteroid colliding with the Earth always exists.

Scientists fear that something similar could happen in 2029, when the giant asteroid Apophis, named after the ancient Egyptian god of destruction, will pass close to our planet. However, time will tell whether the asteroid will collide with the Earth or pass it safely.