Landing on a comet. Why did the scientists land a probe on the surface of a comet?

By all indications, we entered the era of new discoveries. Many last year, with a sinking heart, followed the mission of Rosetta. Landing on a comet, the first in history, was a very complicated operation, like the whole program. However, the difficulties that have arisen do not diminish the significance of both the event itself and the data that the space probe has already produced and is still supplying. Why did we need a landing on a comet and what results did astrophysics get? This will be discussed below.

The main secret

Let's start from afar. One of the main tasks facing the whole scientific world is to understand what contributed to the birth of life on Earth. Since antiquity on this topic, a lot of hypotheses have been expressed. One of the modern versions says that not the last role was played here by comets, which fell in many cases on the planet during its formation. It is believed that they could become suppliers of water and organic molecules.

Evidence of the beginning

This hypothesis in itself perfectly justifies the interest of scientists, from astronomers to biologists, to comets. However, there are a few more interesting moments. Tailed space objects carry through the space quite detailed information about what happened at the earliest stages of the formation of the solar system. It was then that most comets were formed. Thus, landing on a comet makes it possible to literally study the matter from which our piece of the Universe was formed more than four billion years ago (and no time machine is needed).

In addition, the study of the movement of the comet, its composition and behavior when approaching the Sun gives a huge amount of information about such space objects, allows you to test a lot of assumptions and scientific hypotheses.

Background

Naturally, the tailed "travelers" have already been studied with the help of spacecraft. Seven spans were flown by comets, during which photographs were taken, certain information was collected. These were just overflights, because long-term maintenance of a comet is a complicated matter. In the 80s, the US-European ICE apparatus and the Soviet Vega acted as the producers of such data. The last of such meetings occurred in 2011. Then the data on the tailed space object was collected by the apparatus Stardust.

Previous studies have given scientists a lot of information, but to understand the specifics of comets and the answer to many of the above issues is not enough. Gradually, scientists came to realize the need for a fairly bold step - the organization of the flight of the spacecraft to the comet, followed by landing the probe on its surface.

Mission uniqueness

In order to experience how much the landing on the comet is a difficult operation, it is necessary to understand what the cosmic body is in general . It rushes through space at a tremendous speed, sometimes reaching several hundred kilometers per second. At the same time, the comet's tail, formed when the body approaches the Sun and looks so beautiful from the Earth, is a mixture of gas and dust. All this greatly complicates not only planting, but also the movement in a parallel course. It is necessary to equalize the speed of the device with the speed of the object and choose the right moment for rapprochement: the closer the comet to the Sun, the stronger the emissions from its surface. And only then can be carried out landing on the comet, which will be further complicated and low indicators of gravity.

Select an object

All these circumstances made necessary a careful approach to the selection of the mission's goal. Landing on the comet Churyumov-Gerasimenko is not the first option. Initially, it was assumed that the probe "Rosetta" would be sent to the comet of Virtanen. However, the plans were interrupted by the case: shortly before the alleged dispatch the engine from the Ariane-5 launch vehicle refused. It was she who was supposed to bring the Rosetta into space. As a result, the launch was postponed and it became necessary to select a new object. They became the comet Churyumov-Gerasimenko or 67P.

This space object was discovered in 1969 and named after the discoverers. It belongs to the number of short-period comets and makes one revolution around the Sun in about 6.6 years. There is nothing particularly remarkable about the 67P, but it has a well-studied flight trajectory that does not go beyond the orbit of Jupiter. It was to her that Rosetta set out on March 2, 2004.

"Filling" spacecraft

The Rosetta probe carried a large amount of equipment into space, designed for research and fixing their results. Among them are cameras capable of detecting radiation in the ultraviolet part of the spectrum, and apparatuses necessary for studying the structure of the comet and soil analysis, and instruments for studying the atmosphere. In total, 11 scientific tools were available to Rosetta.

Separately, we need to dwell on the downlink module "Fila" - it was he who was to land on the comet. Some of the high-tech equipment was placed directly on it, since it was necessary to study the space object immediately after the landing. In addition, the "Philae" was equipped with three harpoons for reliable fixation on the surface after it was lowered by "Rosetta". Landing on a comet, as already mentioned, involves certain difficulties. Gravity here is so small that in the absence of additional attachments the module runs the risk of getting lost in open space.

Long way

The landing on the comet in 2014 was preceded by a ten-year flight of the Rosetta probe. During this time, he was five times near Earth, flew near Mars, met two asteroids. Magnificent images taken by the probe during this period, once again recall the beauty of nature and the universe in its various parts.

However, a logical question may arise: why Rosetta has been circling the Solar System for so long? It is clear that the photos and other data collected during the flight were not his goal, but rather, became a pleasant and interesting bonus for researchers. The purpose of this maneuver is to approach the comet from behind and equalize the speed. The result of a ten-year flight was the actual conversion of Rosetta into a companion of the comet Churyumov-Gerasimenko.

Convergence

Now, in April 2015, we can say with certainty that the probe landing on the comet as a whole was successful. However, in August of last year, when the device only entered the orbit of the cosmic body, it was still a matter of the near future.

The probe landed on a comet on November 12, 2014. Almost the entire world followed the landing. Undocking "Fila" was a success. The problems started at the moment of landing: the harpoons did not work and the device could not fix on the surface. "Fily" bounced twice from the comet and only for the third time was able to descend, and it flew from the place of the alleged landing about a kilometer.

As a result, the module "Fila" was in a zone where the sun's rays do not penetrate , which are necessary for replenishing the energy charge of batteries. In case the landing on the comet is not entirely successful, the device was equipped with a charged battery, designed for 64 hours. He worked a little less, 57 hours, but during this time, "Phil" managed to do almost everything for what was created.

results

Landing on the comet Churyumov-Gerasimenko allowed scientists to obtain extensive data about this space body. Many of them have not yet been processed or require analysis, but the first results are already presented to the general public.

The studied cosmic body is similar in shape to the rubber dentition (landing on the comet was supposed to be in the "head" area): two comparable rounded parts are connected by a narrow isthmus. One of the tasks facing astrophysicists is to understand the reason for this unusual silhouette. Today, two main hypotheses are put forward: either it is the result of a collision between two bodies, or erosion processes have led to the formation of an isthmus. At the moment, no exact answer has been received. Thanks to the research of "Fila" it became known only that the level of gravity on the comet is not the same. The largest indicator is observed in the upper part of the nucleus, and the smallest - just in the region of the "neck".

Relief and internal structure

Module "Fily" found on the surface of the comet various formations, in appearance resembling mountains and dunes. In their composition, most of them are a mixture of ice and dust. Hills up to 3 meters high, called goose bumps, are quite common on 67P. Scientists suggest that they formed at the first stages of the formation of the solar system and can cover the surface of other similar celestial bodies.

Since the probe on the comet did not descend in the most successful way, scientists were afraid to start the planned drilling of the surface. However, he did it all the same. It turned out that under the upper layer is another, more dense. Most likely, it consists of ice. This assumption is supported by an analysis of the vibrations recorded by the apparatus during landing. At the same time, the photographs of spectrographs show an unequal correlation of organic compounds and ice: the former are clearly larger. This does not agree with the assumptions of scientists and calls into question the version of the origin of the comet. It was assumed that it was formed in the solar system, near Jupiter. The study of the images, however, refutes this hypothesis: apparently, 67P formed in the Kuiper belt, located beyond the orbit of Neptune.

The mission continues

The Rosetta spacecraft, who was closely following the activity of the "Fila" module until the moment of his falling asleep, did not leave the Churyumov-Gerasimenko comet until now. He continues to observe the object and send data to Earth. Thus, his responsibilities include fixing dust and gas emissions, which increase as the comet approaches the Sun.

It was previously established that the main source of such emissions is the so-called comet neck. The reason for this may be low gravity of this region and the resulting effect of accumulation of solar energy reflected from neighboring areas. In March of this year, Rosetta also recorded a release of dust and gas, interesting because it occurred on the unlit side (as a rule, such phenomena arise as a result of the surface heating, that is, on the solar part of the comet). All these processes and features of 67P have yet to be explained, while the collection of data continues.

The first landing in the history of mankind on the surface of a comet was the result of the work of a large number of scientists, technicians, engineers and designers for almost forty years. Today, the Rosetta mission is recognized as one of the most ambitious events of the space age. Naturally, astrophysicists do not intend to put an end to this. Among the ambitious plans for the future is the creation of a descent module that will be able to move around the surface of the comet, and a spacecraft that can approach the object, collect soil samples and return with them to Earth. In general, the successful project Rosetta inspires scientists to more and more daring programs to develop the secrets of the universe.