The largest mirror telescope in the world. Large azimuthal telescope

What can be seen with a telescope?

One of the most FAQ: What can you see with a telescope? With the right approach and choice of instrument, you can see many interesting objects in the sky. The visibility of space objects depends on the lens diameter. The larger the diameter, the more the telescope will collect light from the object, and the finer details we will be able to distinguish.

Consider options. These photographs were taken with ideal conditions observations. And it is worth noting that the human eye perceives colors differently.

1. What can be seen with a 60-70mm or 70-80mm telescope

These devices are the most popular among beginners. Most of them can also be used as a spotting scope for terrestrial objects.

With their help, you can see many objects in the sky, for example, craters on the Moon with a diameter of 8 km, spots on the sun (only with an aperture filter), four moons of Jupiter, phases of Venus, Lunar craters with a diameter of 7-10 km, cloud bands on Jupiter and 4 its moon, the rings of Saturn.

Photos of objects that were taken with a telescope with a diameter of 60-80 mm:

List of recommended telescopes with a lens diameter of 60, 70, 80 mm:

2. What can be seen in the telescope refractor 80-90 mm, reflector 100-120 mm, catadioptric 90-125 mm

In telescopes with this diameter, you will see lunar craters about 5 km in size, the structure of sunspots, granulation and flare fields. Always use a sun filter! Mars will be visible as a small circle. You can also see the Cassini gap in the rings of Saturn and 4-5 satellites, the Great Red Spot (GRS) on Jupiter, etc.

Photos of objects that were taken through a telescope with this lens diameter:

List of recommended telescopes with a lens diameter of 80, 90, 100-125 mm:

3. What can be seen in a 100-130 mm refractor, reflector or catadioptric 127-150 mm telescope.

These models will allow you to consider space in more detail. With this diameter, you will be able to achieve significant success in astronomy and see:

4. What can be seen in a telescope refractor 150-180 mm, reflector or catadioptric 127-150 mm

It is better to use it only for out-of-town observations, since using them in urban conditions will prevent the aperture from reaching its full potential due to excess urban illumination. Refractors of these diameters are quite difficult to find, because their cost is much higher than reflectors and mirror-lens telescopes with the same parameters.

With their help, you can see double stars with a separation of less than 1″, faint stars up to 14 stars. magnitudes, lunar formations 2 km in size, 6-7 satellites of Saturn and other space objects.

Photos of objects that were taken with a telescope with a given diameter:

B.M. Shustov, Doctor of Physical and Mathematical Sciences,
Institute of Astronomy RAS

Mankind has gathered the bulk of knowledge about the Universe using optical instruments - telescopes. Already the first telescope, invented by Galileo in 1610, made it possible to make great astronomical discoveries. Over the next centuries, astronomical technology was continuously improved and the modern level of optical astronomy is determined by the data obtained using instruments hundreds of times larger than the first telescopes.

The trend towards ever larger instruments has become particularly clear in recent decades. Telescopes with a mirror with a diameter of 8 - 10 m are becoming common in observational practice. Projects of 30-m and even 100-m telescopes are estimated as quite feasible already in 10 - 20 years.

Why are they being built

The need to build such telescopes is determined by tasks that require the ultimate sensitivity of instruments for detecting radiation from the faintest space objects. These tasks include:

• the origin of the universe;
• mechanisms of formation and evolution of stars, galaxies and planetary systems;
• physical properties of matter in extreme astrophysical conditions;
• astrophysical aspects of the origin and existence of life in the Universe.

To get the maximum information about an astronomical object, a modern telescope must have large area of ​​collecting optics and high efficiency of radiation receivers. Besides, Observation interference should be kept to a minimum..

At present, the efficiency of receivers in the optical range, understood as the fraction of detected photons from the total number of photons that arrived at the sensitive surface, is approaching the theoretical limit (100%), and further improvements are associated with increasing the format of receivers, speeding up signal processing, etc.

Observation interference is a very serious problem. In addition to interference of a natural nature (for example, cloudiness, dust formations in the atmosphere), the existence of optical astronomy as an observational science is threatened by increasing illumination from settlements, industrial centers, communications, and man-made pollution of the atmosphere. Modern observatories are built, of course, in places with a favorable astroclimate. There are very few such places on the globe, no more than a dozen. Unfortunately, there are no places with a very good astroclimate on the territory of Russia.

The only promising direction in the development of highly efficient astronomical technology is to increase the size of the collecting surfaces of instruments.

The largest telescopes: the experience of creation and use

In the last decade, more than a dozen projects of large telescopes have been implemented or are in the process of being developed and created in the world. Some projects provide for the construction of several telescopes at once with a mirror no less than 8 m in size. The cost of the instrument is determined primarily by the size of the optics. Centuries of hands-on experience in telescope construction have led to easy way a comparative estimate of the cost of a telescope S with a mirror of diameter D (let me remind you that all instruments with a primary mirror diameter greater than 1 m are reflecting telescopes). For telescopes with a solid primary mirror, as a rule, S is proportional to D 3 . Analyzing the table, you can see that this classic ratio for the largest instruments is violated. Such telescopes are cheaper and for them S is proportional to D a , where a does not exceed 2.

It is the stunning reduction in cost that makes it possible to consider projects of supergiant telescopes with a mirror diameter of tens and even hundreds of meters not as fantasies, but as quite real projects in the near future. We will talk about some of the most cost-effective projects. One of them, SALT, is being commissioned in 2005, the construction of giant telescopes of 30-meter class ELT and 100-meter - OWL has not yet begun, but they may appear in 10 - 20 years.

TELESCOPE	mirror diameter, m	Main mirror parameters	Location of the telescope	Project participants	Project cost, million $ USD	first light
KECKI KECK II		parabolic multi-segment active	Mauna Kea, Hawaii, USA	USA
VLT (four telescopes)		thin active	Chile	ESO, cooperation of nine European countries
GEMINI North GEMINI South		thin active	Mauna Kea, Hawaii, USA Cerro Pachon, Chile	USA (25%), England (25%), Canada (15%), Chile (5%), Argentina (2.5%), Brazil (2.5%)
SUBARU		thin active	Mauna Kea, Hawaii, USA	Japan
LBT (binocular)		cellular thick	Mt. Graham, Arizona, USA	USA, Italy
NO(Hobby&Eberly)	11 (actually 9.5)	spherical multi-segment	Mt. Fowlkes, Texac, USA	USA, Germany
MMT		cellular thick	Mt. Hopkins, Arizona, USA	USA
MAGELLAN two telescopes		cellular thick	Las Campanas, Chile	USA
BTA SAO RAS		thick	Mount Pastukhova, Karachay-Cherkessia	Russia
GTC		analogue of KECK II	La Palma , Canary Islands, Spain	Spain 51%
SALT		analogue NO	Sutherland, South Africa	Republic of South Africa
ELT	35 (actually 28)	analogue NO		USA	150-200 preliminary project
OWL		spherical multisegment mental		Germany, Sweden, Denmark, etc.	About 1000 avant-project

Large South African Telescope SALT

In the 1970s South Africa's main observatories were merged into the South African Astronomical Observatory. The headquarters is located in Cape Town. The main instruments - four telescopes (1.9-m, 1.0-m, 0.75-m and 0.5-m) - are located 370 km from the city inland, on a hill rising on the dry Karoo plateau ( Karoo).

South African Astronomical Observatory.
South African Large Telescope Tower
shown in section. In front of her are three main
operating telescopes. (1.9m, 1.0m and 0.75m).

In 1948, a 1.9-m telescope was built in South Africa, it was the largest instrument in the southern hemisphere. In the 90s. last century, the scientific community and the government of South Africa decided that South African astronomy could not remain competitive in the 21st century without a modern large telescope. Initially, a 4-m telescope similar to the ESO NTT (New Technology Telescope) was considered. New Technology) or more modern, WIYN, at Kitt Peak Observatory. However, in the end, the concept of a large telescope was chosen - an analogue of the Hobby-Eberly Telescope (HET) installed at the McDonald Observatory (USA). The project was named Large South African Telescope, in original - Southern African Large Telescope (SALT).

The cost of the project for a telescope of this class is very low - only 20 million US dollars. Moreover, the cost of the telescope itself is only half of this amount, the rest is the cost of the tower and infrastructure. Another 10 million dollars, according to modern assessment, the maintenance of the tool for 10 years will cost. Such a low cost is due to both the simplified design and the fact that it is created as an analogue of the already developed one.

SALT (respectively, HET) are radically different from previous projects of large optical (infrared) telescopes. The optical axis of SALT is set at a fixed angle of 35° to the zenith direction, and the telescope is able to rotate in azimuth for a full circle. During the observation session, the instrument remains stationary, and the tracking system, located in its upper part, provides tracking of the object in a 12° section along the altitude circle. Thus, the telescope makes it possible to observe objects in a ring 12° wide in the region of the sky that is 29 - 41° away from the zenith. The angle between the telescope axis and the zenith direction can be changed (no more than once every few years) by studying different regions of the sky.

The diameter of the main mirror is 11 m. However, its maximum area used for imaging or spectroscopy corresponds to a 9.2 m mirror. It consists of 91 hexagonal segments, each with a diameter of 1 m. All segments have a spherical surface, which greatly reduces the cost of their production. By the way, the blanks of the segments were made at the Lytkarino Optical Glass Plant, the primary processing was carried out there, the final polishing is carried out (at the time of writing the article has not yet been completed) by Kodak. The Gregory corrector, which removes spherical aberration, is effective in the 4? region. Light can be transmitted via optical fibers to spectrographs of various resolutions in thermostatically controlled rooms. It is also possible to set a light instrument in direct focus.

The Hobby-Eberle telescope, and hence the SALT, are essentially designed as spectroscopic instruments for wavelengths in the 0.35-2.0 µm range. SALT is most competitive from a scientific point of view when observing astronomical objects that are evenly distributed across the sky or located in groups of several arc minutes in size. Since the telescope will operate in batch mode ( queue-scheduled), studies of variability during a day or more are especially effective. The range of tasks for such a telescope is very wide: studies of the chemical composition and evolution of the Milky Way and nearby galaxies, the study of objects with a large redshift, the evolution of gas in galaxies, the kinematics of gas, stars and planetary nebulae in distant galaxies, the search for and study of optical objects identified with x-ray sources. The SALT telescope is located on top of the South African Observatory telescopes, approximately 18 km east of the village of Sutherland ( Sutherland) at an altitude of 1758 m. Its coordinates are 20 ° 49 "East longitude and 32 ° 23" South latitude. The construction of the tower and infrastructure has already been completed. The journey by car from Cape Town takes approximately 4 hours. Sutherland is located far from all the main cities, so it has very clear and dark skies. Statistical studies of the results of preliminary observations, which have been carried out for more than 10 years, show that the proportion of photometric nights exceeds 50%, and spectroscopic nights average 75%. Since this large telescope is primarily optimized for spectroscopy, 75% is a perfectly acceptable figure.

The average atmospheric image quality measured by the Differential Motion Image Monitor (DIMM) was 0.9". This system is placed slightly above 1 m above the ground. Note that the optical image quality of SALT is 0.6". This is sufficient for work on spectroscopy.

ELT and GSMT Extremely Large Telescope Projects

In the USA, Canada and Sweden, several projects of class 30 telescopes are being developed at once - ELT, MAXAT, CELT, etc. There are at least six such projects. In my opinion, the most advanced of them are the American projects ELT and GSMT.

Project ELT (Extremely Large Telescope - Extremely Large Telescope) - a larger copy of the HET telescope (and SALT), will have an entrance pupil diameter of 28 m with a mirror diameter of 35 m. The telescope will achieve a penetrating power an order of magnitude higher than that of modern class 10 telescopes. The total cost of the project is estimated at about 100 million US dollars. It is being developed at the University of Texas (Austin), where experience has already been accumulated in building the HET telescope, the University of Pennsylvania and the McDonald Observatory. This is the most realistic project to implement no later than the middle of the next decade.

GSMT project (Giant Segmented Mirror Telescope - Giant Segmented Mirror Telescope) can be considered to some extent uniting the MAXAT (Maximum Aperture Telescope) and CELT (California Extremely Lerge Telescope) projects. The competitive way of developing and designing such expensive tools is extremely useful and is used in world practice. The final decision on GSMT has not yet been made.

The GSMT telescope is significantly more advanced than the ELT, and its cost will be about 700 million US dollars. This is much higher than that of the ELT due to the introduction aspherical main mirror, and the planned full turn

Stunningly Large OWL Telescope

The most ambitious project of the beginning of the XXI century. is, of course, a project OWL (OverWhelmingly Large Telescope - Stunningly Large Telescope) . The OWL is being designed by the European Southern Observatory as an alt-azimuth telescope with a segmented spherical primary and flat secondary mirrors. To correct spherical aberration, a 4-element corrector with a diameter of about 8 m is introduced. modern projects technologies: active optics (as on NTT, VLT, Subaru, Gemini telescopes), which allows obtaining an image of optimal quality; primary mirror segmentation (as on Keck, HET, GTC, SALT), low cost designs (as on HET and SALT), and multi-stage adaptive optics being developed ( "Earth and Universe", 2004, No. 1).

The Astonishingly Large Telescope (OWL) is being designed by the European Southern Observatory. Its main characteristics are: the diameter of the entrance pupil is 100 m, the area of ​​the collecting surface is over 6000 sq. m, multi-stage adaptive optics system, diffraction image quality for the visible part of the spectrum - in the field 30", for the near infrared - in the field 2"; the field limited by the image quality allowed by the atmosphere (seeing) is 10"; the relative aperture is f / 8; the working spectral range is 0.32-2 microns. The telescope will weigh 12.5 thousand tons.

It should be noted that this telescope will have a huge working field (hundreds of billions of ordinary pixels!). How many powerful receivers can be placed on this telescope!

The concept of gradual commissioning of OWL has been adopted. It is proposed to start using the telescope as early as 3 years before the filling of the primary mirror. The plan is to fill the 60 m aperture by 2012 (if funding opens in 2006). The cost of the project is no more than 1 billion euros (the latest estimate is 905 million euros).

Russian perspectives

About 30 years ago, a 6-m telescope was built and put into operation in the USSR BTA (Large Azimuth Telescope) . For many years it remained the largest in the world and, of course, was the pride of Russian science. BTA demonstrated a number of original technical solutions (for example, alt-azimuth installation with computer guidance), which later became the world technical standard. BTA is still a powerful tool (especially for spectroscopic studies), but at the beginning of the XXI century. it has already found itself only in the second ten largest telescopes in the world. In addition, the gradual degradation of the mirror (now its quality has deteriorated by 30% compared to the original) removes it from the list of effective tools.

With the collapse of the USSR, BTA remained practically the only major instrument available to Russian researchers. All observation bases with moderate-sized telescopes in the Caucasus and Central Asia have significantly lost their significance as regular observatories due to a number of geopolitical and economic reasons. Work has now begun to restore ties and structures, but the historical prospects for this process are vague, and in any case, it will take many years only to partially restore what has been lost.

Of course, the development of the fleet of large telescopes in the world provides an opportunity for Russian observers to work in the so-called guest mode. The choice of such a passive path would invariably mean that Russian astronomy would always play only secondary (dependent) roles, and the lack of a base for domestic technological developments would lead to a deepening lag, and not only in astronomy. The way out is obvious - a radical modernization of BTA, as well as full-fledged participation in international projects.

The cost of large astronomical instruments, as a rule, amounts to tens and even hundreds of millions of dollars. Such projects, with the exception of a few national projects implemented richest countries of the world, can only be realized on the basis of international cooperation.

Opportunities for cooperation in the construction of class 10 telescopes appeared at the end of the last century, but the lack of funding, or rather the state interest in the development of domestic science, led to the fact that they were lost. A few years ago, Russia received an offer to become a partner in the construction of a large astrophysical instrument - the Great Canary Telescope (GTC) and the even more financially attractive SALT project. Unfortunately, these telescopes are being built without the participation of Russia.

Thanks to telescopes, scientists have made amazing discoveries: they discovered a huge number of planets beyond solar system learned about the existence of black holes at the centers of galaxies. But the Universe is so huge that this is only a grain of knowledge. Here are ten current and future giants of ground-based telescopes that give scientists the opportunity to study the past of the universe and learn new facts. Perhaps with the help of one of them it will even be possible to detect the Ninth planet.

BigSouth Africantelescope (SALT)

This 9.2-meter telescope is the largest ground-based optical instrument in the southern hemisphere. It has been operating since 2005 and focuses on spectroscopic surveys (registers spectra various kinds radiation). The instrument can view about 70% of the sky observed in Sutherland, South Africa.

Keck I and II telescopes

The twin 10-meter telescopes at the Keck Observatory are the second largest optical instruments on Earth. They are located near the top of Mauna Kea in Hawaii. Keck I started operating in 1993. A few years later, in 1996, the Keck II. In 2004, the first adaptive optics system with a laser guide star was deployed at the combined telescopes. It creates an artificial star spot as a guide to correct atmospheric distortion when viewing the sky.

Photo: ctrl.info

Great Telescope of the Canaries (GTC)

The 10.4-meter telescope is located on the peak of the extinct volcano Muchachos on the Canary island of Palma. It is known as an optical instrument with the largest mirror in the world. It consists of 36 hexagonal segments. GTC has several support tools. For example, the CanariCam camera, which is capable of examining the mid-range infrared light emitted by stars and planets. CanariCam also has the unique ability to block out bright starlight and make faint planets more visible in photographs.

Photo: astro.ufl

Arecibo Observatory Radio Telescope

It is one of the world's most recognizable ground-based telescopes. It has been operating since 1963 and is a huge 30-meter radio reflecting dish near the city of Arecibo in Puerto Rico. The huge reflector makes the telescope particularly sensitive. It is able to detect a weak radio source (distant quasars and galaxies that emit radio waves) in just a few minutes of observation.

Photo: physics world

ALMA Radio Telescope Complex

One of the largest ground-based astronomical instruments is presented in the form of 66 12-meter radio antennas. The complex is located at an altitude of 5000 meters in the Atacama Desert in Chile. The first scientific studies were carried out in 2011. ALMA radio telescopes have one important purpose. With their help, astronomers want to study the processes that took place during the first hundreds of millions of years after the Big Bang.

Photo: Wikipedia

Up to this point, we have been talking about already existing telescopes. But now many new ones are being built. Very soon they will begin to function and significantly expand the possibilities of science.

LSST

This is a wide-angle reflecting telescope that will take pictures of a certain area of ​​the sky every few nights. It will be located in Chile, on top of Mount Sero Pachon. While the project is only in development. The full operation of the telescope is planned for 2022. Nevertheless, high hopes are already pinned on him. Astronomers expect the LSST to give them the best view of celestial bodies far from the Sun. Scientists also suggest that this telescope will be able to notice space rocks that could theoretically collide with the Earth in the future.

Photo: LSST

Giant Magellan Telescope

The telescope, which is expected to be completed by 2022, will be located at the Las Campanas Observatory in Chile. Scientists believe that the telescope will have four times the ability to collect light compared to currently existing optical instruments. With it, astronomers will be able to discover exoplanets (planets outside the solar system) and study the properties of dark matter.

Photo: Wikipedia

Thirty meter telescope

The 30-meter telescope will be located in Hawaii, next to the Keck Observatory. It is planned that it will begin to operate in 2025-2030. The aperture of the device is capable of providing a resolution 12 times higher than that of the Hubble Space Telescope.

Photo: Wikipedia

SKA radio telescope

SKA antennas will be deployed in South Africa and Australia. Now the project is still under construction. But the first observations are planned for 2020. The sensitivity of the SKA will be 50 times that of any radio telescope ever built. With its help, astronomers will be able to study signals from a younger universe - the time when the formation of the first stars and galaxies took place.

Photo: Wikipedia

Extremely Large Telescope (ELT)

The telescope will be located on the Cerro Amazone mountain in Chile. It is planned that it will start working only in 2025. However, he has already become famous for the huge mirror, which will consist of 798 hexagonal segments with a diameter of 1.4 meters each. Specifications ELT will allow him to study the composition of the atmospheres of extrasolar planets.

Photo: Wikipedia

10 largest telescopes

Far from the lights and noise of civilization, on the tops of mountains and in deserted deserts, titans live, whose multi-meter eyes are always turned to the stars.

We have selected 10 largest ground-based telescopes: some have been contemplating space for many years, others have yet to see the “first light”.

10Large Synoptic Survey Telescope

Main mirror diameter: 8.4 meters

Location: Chile, the peak of Mount Sero Pachon, 2682 meters above sea level

Type: reflector, optical

Although the LSST will be located in Chile, this is a US project and its construction is entirely financed by the Americans, including Bill Gates (personally invested $10 million of the required $400).

The purpose of the telescope is to photograph the entire available night sky every few nights, for this the device is equipped with a 3.2 gigapixel camera. LSST stands out with a very wide viewing angle of 3.5 degrees (for comparison, the Moon and Sun, as seen from Earth, occupy only 0.5 degrees). Such possibilities are explained not only by the impressive diameter of the main mirror, but also by the unique design: instead of two standard mirrors, LSST uses three.

Among the scientific goals of the project are the search for manifestations of dark matter and dark energy, mapping the Milky Way, detecting short-term events like nova or supernova explosions, as well as registering small objects in the solar system like asteroids and comets, in particular, near the Earth and in the Kuiper Belt.

The LSST is expected to see its “first light” (a common Western term for when the telescope is first used for its intended purpose) in 2020. At the moment, construction is underway, the release of the device to full operation is scheduled for 2022.

Large Synoptic Survey Telescope concept

9South African Large Telescope

Main mirror diameter: 11 x 9.8 meters

Location: South Africa, hilltop near the settlement of Sutherland, 1798 meters above sea level

Type: reflector, optical

The largest optical telescope in the southern hemisphere is located in South Africa, in a semi-desert area near the city of Sutherland. A third of the $36 million needed to build the telescope came from the South African government; the rest is divided between Poland, Germany, Great Britain, the USA and New Zealand.

SALT took his first picture in 2005, shortly after construction was completed. Its design is rather non-standard for optical telescopes, but it is widespread among the latest generation of "very large telescopes": the primary mirror is not a single one and consists of 91 hexagonal mirrors with a diameter of 1 meter, the angle of inclination of each of which can be adjusted to achieve a certain visibility.

Designed for visual and spectrometric analysis of radiation from astronomical objects inaccessible to telescopes of the northern hemisphere. Employees of SALT are engaged in observations of quasars, nearby and distant galaxies, and also follow the evolution of stars.

There is a similar telescope in the States, it is called the Hobby-Eberly Telescope and is located in Texas, in the town of Fort Davis. Both the diameter of the mirror and its technology are almost identical to SALT.

South African Large Telescope

8. Keck I and Keck II

Main mirror diameter: 10 meters (both)

Location: USA, Hawaii, Mauna Kea, 4145 meters above sea level

Type: reflector, optical

Both of these American telescopes are connected into one system (astronomical interferometer) and can work together to create a single image. The unique location of the telescopes in one of the best places on Earth in terms of astroclimate (the degree to which the atmosphere interferes with the quality of astronomical observations) has made Keck one of the most efficient observatories in history.

The main mirrors of Keck I and Keck II are identical to each other and are similar in structure to the SALT telescope: they consist of 36 hexagonal moving elements. The equipment of the observatory makes it possible to observe the sky not only in the optical but also in the near infrared range.

In addition to the bulk of the widest range of research, Keck is currently one of the most effective ground-based tools in the search for exoplanets.

Keck at sunset

7. Gran Telescopio Canarias

Main mirror diameter: 10.4 meters

Location: Spain, Canary Islands, La Palma island, 2267 meters above sea level

Type: reflector, optical

The construction of the GTC ended in 2009, at the same time the observatory was officially opened. Even the king of Spain, Juan Carlos I, came to the ceremony. In total, 130 million euros were spent on the project: 90% was financed by Spain, and the remaining 10% was equally divided by Mexico and the University of Florida.

The telescope is capable of observing stars in the optical and mid-infrared range, has CanariCam and Osiris instruments, which allow the GTC to conduct spectrometric, polarimetric and coronographic studies of astronomical objects.

Gran Telescopio Camarias

6. Arecibo Observatory

Main mirror diameter: 304.8 meters

Location: Puerto Rico, Arecibo, 497 meters above sea level

Type: reflector, radio telescope

One of the most recognizable telescopes in the world, the Arecibo radio telescope has been seen by cameras on numerous occasions: for example, the observatory was featured as the site of the final confrontation between James Bond and his antagonist in the movie GoldenEye, as well as in the sci-fi adaptation of Carl's novel Sagan "Contact".

This radio telescope has even made its way into video games - in particular, in one of the Battlefield 4 multiplayer maps called Rogue Transmission, a military clash between the two sides takes place just around the structure, completely copied from Arecibo.

Arecibo looks really unusual: a giant telescope dish with a diameter of almost a third of a kilometer is placed in a natural karst funnel surrounded by jungle and covered with aluminum. A movable antenna feed is suspended above it, supported by 18 cables from three high towers along the edges of the reflector dish. Giant construction allows Arecibo to catch electromagnetic radiation relatively large range - with a wavelength from 3 cm to 1 m.

Introduced back in the 60s, this radio telescope has been used in countless studies and managed to make a number of significant discoveries (like the first asteroid 4769 Castalia discovered by the telescope). Once Arecibo even provided scientists Nobel Prize: Hulse and Taylor were awarded in 1974 for the first ever discovery of a pulsar in a binary star system (PSR B1913+16).

In the late 1990s, the observatory also began to be used as one of the instruments of the US SETI project to search for extraterrestrial life.

Arecibo Observatory

5. Atacama Large Millimeter Array

Main mirror diameter: 12 and 7 meters

Location: Chile, Atacama Desert, 5058 meters above sea level

Type: radio interferometer

At the moment, this astronomical interferometer of 66 radio telescopes of 12 and 7 meters in diameter is the most expensive operating ground-based telescope. The US, Japan, Taiwan, Canada, Europe and, of course, Chile spent about $1.4 billion on it.

Since the purpose of ALMA is to study millimeter and submillimeter waves, the most favorable for such an apparatus is a dry and high-mountain climate; this explains the location of all six and a half dozen telescopes on the desert Chilean plateau 5 km above sea level.

The telescopes were delivered gradually, with the first radio antenna operational in 2008 and the last one in March 2013, when ALMA was officially launched at full capacity.

The main scientific goal of the giant interferometer is to study the evolution of the cosmos at the earliest stages of the development of the Universe; in particular, the birth and further dynamics of the first stars.

Radio telescopes of the ALMA system

4Giant Magellan Telescope

Main mirror diameter: 25.4 meters

Location: Chile, Las Campanas Observatory, 2516 meters above sea level

Type: reflector, optical

Far southwest of ALMA, in the same Atacama desert, another large telescope is under construction, a US and Australian project, the GMT. The main mirror will consist of one central and six symmetrically surrounding and slightly curved segments, forming a single reflector with a diameter of more than 25 meters. In addition to a huge reflector, the telescope will be equipped with the latest adaptive optics, which will make it possible to eliminate the distortions created by the atmosphere during observations as much as possible.

Scientists hope these factors will allow the GMT to capture images 10 times sharper than Hubble's, and probably even better than its long-awaited successor, the James Webb Space Telescope.

Among the scientific goals of GMT is a very wide range of research - the search for and images of exoplanets, the study of planetary, stellar and galactic evolution, the study of black holes, manifestations of dark energy, as well as the observation of the very first generation of galaxies. The operating range of the telescope in connection with the stated goals is optical, near and mid-infrared.

All work is expected to be completed by 2020, however, it is stated that GMT can see the "first light" already with 4 mirrors, as soon as they are introduced into the design. At the moment, work is underway to create the fourth mirror.

Giant Magellan Telescope Concept

3. Thirty Meter Telescope

Main mirror diameter: 30 meters

Location: USA, Hawaii, Mauna Kea, 4050 meters above sea level

Type: reflector, optical

The TMT is similar in purpose and performance to the GMT and the Hawaiian Keck telescopes. It is on the success of Keck that the larger TMT is based, with the same technology of a primary mirror divided into many hexagonal elements (only this time its diameter is three times larger), and the stated research goals of the project almost completely coincide with those of the GMT, up to photographing the earliest galaxies almost at the edge of the universe.

The media name the different cost of the project, it varies from 900 million to 1.3 billion dollars. It is known that India and China have expressed their desire to participate in TMT, which agree to take on part of the financial obligations.

At the moment, a place has been chosen for construction, but there is still opposition from some forces in the administration of Hawaii. Mauna Kea is a sacred place for native Hawaiians, and many among them are strongly opposed to the construction of a super-large telescope.

It is assumed that all administrative problems will be resolved very soon, and it is planned to complete the construction around 2022.

Thirty Meter Telescope Concept

2. Square Kilometer Array

Main mirror diameter: 200 or 90 meters

Location: Australia and South Africa

Type: radio interferometer

If this interferometer is built, it will become 50 times more powerful astronomical instrument than the Earth's largest radio telescopes. The fact is that with its antennas, SKA must cover an area of ​​\u200b\u200babout 1 square kilometer, which will provide it with unprecedented sensitivity.

In terms of structure, SKA is very similar to the ALMA project, however, in terms of dimensions it will significantly exceed its Chilean counterpart. At the moment, there are two formulas: either build 30 radio telescopes with antennas of 200 meters, or 150 with a diameter of 90 meters. One way or another, the length on which the telescopes will be placed will be, according to the plans of scientists, 3000 km.

To choose the country where the telescope will be built, a kind of competition was held. Australia and South Africa reached the final, and in 2012 a special commission announced its decision: the antennas will be distributed between Africa and Australia in a common system, that is, the SKA will be located on the territory of both countries.

The declared cost of the megaproject is $2 billion. The amount is divided among a number of countries: the UK, Germany, China, Australia, New Zealand, the Netherlands, South Africa, Italy, Canada and even Sweden. Construction is expected to be fully completed by 2020.

Artistic depiction of the 5 km SKA core

1. European Extremely Large Telescope

Main mirror diameter: 39.3 meters

Location: Chile, Cerro Armazones, 3060 meters

Type: reflector, optical

For a couple of years, perhaps. However, by 2025, a telescope will reach its full capacity, which will surpass TMT by a whole dozen meters and which, unlike the Hawaiian project, is already under construction. This is the undisputed leader of the latest generation of large telescopes, the European Very Large Telescope, or E-ELT.

Its main almost 40-meter mirror will consist of 798 moving elements with a diameter of 1.45 meters. This, together with the most advanced adaptive optics system, will make the telescope so powerful that, according to scientists, it will not only be able to find planets similar to Earth in size, but will also be able to study the composition of their atmosphere with the help of a spectrograph, which opens up completely new perspectives in the study planets outside the solar system.

In addition to searching for exoplanets, E-ELT will study the early stages of space development, try to measure the exact acceleration of the expansion of the Universe, check physical constants for, in fact, constancy over time; also this telescope will allow scientists to dive deeper than ever into the processes of planet formation and their primary chemical composition in search of water and organics - that is, E-ELT will help answer a number of fundamental questions of science, including those that affect the origin of life.

The cost of the telescope announced by representatives of the European Southern Observatory (the authors of the project) is 1 billion euros.

European Extremely Large Telescope Concept

Size comparison of E-ELT and Egyptian pyramids