By all indications, we entered the era of newdiscoveries. 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 least role was played here by comets, many of which fell 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 itself is beautifulsubstantiates 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 motion of a comet, its compositionand behavior when approaching the Sun gives a huge amount of information about similar space objects, allows you to test a lot of assumptions and scientific hypotheses.
Naturally, tailed "travelers" alreadywere studied with the help of spacecraft. Seven spans were passed past the 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 American-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 lotHowever, to understand the specifics of comets and the answer to many of the above issues, this 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 and the subsequent landing of the probe on its surface.
In order to feel how much the landingon a comet is not an easy operation, you need to understand what the cosmic body is in general. It rushes through space at a tremendous speed, sometimes reaching several hundred kilometers per second. In this case, 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 convergence: 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 it necessarycareful approach to the selection of the purpose of the mission. 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 at 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 there was a need to select a new object. They became the comet Churyumov-Gerasimenko or 67P.
This space object was discovered in 1969and named in honor of 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.
The "filling" of the spacecraft
The Rosetta probe carried a largethe number of equipment intended for research and fixation of 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 it is necessary to stop on the descending module"Filas" - it was he who was to make a landing 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 "Phila" was equipped with three harpoons for reliable fixation on the surface after it was lowered by the "Rosetta". Landing on a comet, as already mentioned, involves some difficulties. Gravity here is so small that in the absence of additional attachments the module runs the risk of getting lost in open space.
The landing on the comet in 2014 was preceded bya 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" so long circled the solar system? It is clear that the photographs 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 the Rosetta into a companion of the Churyumov-Gerasimenko comet.
Now, in April 2015, it is possible with certaintyto say that the landing of the probe 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 on the comet landed on November 12, 2014. Almost the whole 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 the zone wherealmost do not penetrate the sun's rays, which are necessary for replenishing the energy charge of batteries. In case the landing on the comet does not happen very well, 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.
Landing on the comet Churyumov-Gerasimenko allowedscientists get extensive information 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 cosmic body studied in form is similar torubber landing (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 a cometvarious formations, resembling mountains and dunes. By their composition, most of them are a mixture of ice and dust. Hills up to 3 meters high, called goose bumps, at 67P occur quite often. 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 descendsuccessfully, 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
Spacecraft Rosetta, carefullywho was following the activity of the "Fila" module until the moment he fell 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 ofSuch emissions are the so-called neck of the comet. The reason for this may be the low gravity of this region and the resulting effect of accumulation of solar energy reflected from neighboring sites. 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 mankindThe surface of the comet was the result of the work of a large number of scientists, technicians, engineers and designers for nearly 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.