How did telescopes come about?
The first telescope appeared at the beginning of the 17th century: several inventors simultaneously invented telescopes. These tubes were based on the properties of a convex lens (or, as it is also called, a concave mirror), acting as a lens in the tube: the lens collects light rays into focus, and an enlarged image is obtained, which can be viewed through the eyepiece located at the other end of the tube. The important date for telescopes is January 7, 1610; then the Italian Galileo Galilei first directed a telescope into the sky - and that is how he turned it into a telescope. Galileo's telescope was very small, just over a meter in length, and the objective was 53 mm in diameter. Since then, telescopes have grown steadily in size. The really large telescopes in observatories began to be built in the 20th century. The largest optical telescope to date is the Large Canary Telescope, at an observatory in the Canary Islands, with a lens diameter of as much as 10 m.
Are all telescopes the same?
No. The main type of telescopes is optical, they use either a lens, or a concave mirror or a series of mirrors, or a mirror and a lens together. All these telescopes work with visible light - that is, they look at planets, stars and galaxies in about the same way as a very sharp-sighted human eye would look at them. All objects in the world have radiation, and visible light is only a small fraction of the spectrum of these radiation. Looking at space only through it is even worse than seeing the world around in black and white light; so we lose a lot of information. Therefore, there are telescopes that work on different principles - for example, radio telescopes that catch radio waves, or telescopes that catch gamma rays - they are used to observe the hottest objects in space. There are also ultraviolet and infrared telescopes, they are well suited for detecting new planets beyond Solar system: It is impossible to see tiny planets orbiting them in visible light of bright stars, but in ultraviolet and infrared light it is much easier to do this.
Why do you need telescopes at all?
Good question! You should have asked it earlier. We send spacecraft into space and even to other planets, collect information on them, but for the most part astronomy is a unique science, because it studies objects to which it does not have direct access. The telescope is the best tool to get information about space. He sees waves that are inaccessible to the human eye, the smallest details, and also records his observations - then with the help of these records you can notice changes in the sky.
Thanks to modern telescopes, we have a good idea of \u200b\u200bthe stars, planets and galaxies and can even detect hypothetical particles and waves previously unknown to science: for example, dark matter (these are the mysterious particles that make up 73% of the universe) or gravitational waves (They are trying to detect them using the LIGO observatory, which consists of two observatories located at a distance of 3000 km from each other). It is best to do with telescopes for these purposes, as with all other devices - send them into space.
Why send telescopes into space?
The surface of the earth is not the best place for observing space. Our planet creates a lot of interference. First, the air in the planet's atmosphere works like a lens: it distorts light from celestial objects in a random, unpredictable order - and distorts the way we see them. In addition, the atmosphere absorbs many types of radiation, such as infrared and ultraviolet waves. In order to bypass this interference, telescopes are sent into space. True, this is very expensive, so this is rarely done: throughout history we have sent about 100 telescopes of various sizes into space - in fact, this is not enough, even large optical telescopes on Earth are several times larger. The most famous space telescope is the Hubble, and the James Webb Telescope, which is due to launch in 2018, will become something of its successor.
How expensive is it?
A powerful space telescope is very expensive. Last week marked the 25th anniversary of the launch of Hubble, the world's most famous space telescope. About $ 10 billion has been allocated for it for the entire time; part of this money was for repairs, because the Hubble had to be repaired regularly (this was stopped in 2009, but the telescope is still working). Soon after the launch of the telescope, a silly story happened: the first images it took were of much poorer quality than expected. It turned out that due to a tiny error in the calculations, the Hubble mirror was not level enough, and a whole team of astronauts had to be sent to fix it. It cost about $ 8 million. The price of the James Webb telescope may change and is likely to grow closer to launch, but so far it is about $ 8 billion - and it is worth every cent.
What's so special
in the James Webb Telescope?
It will be the most impressive telescope in human history. The project was conceived back in the mid-90s, and now it is finally coming to its final stage. The telescope will fly 1.5 million km from the Earth and enter an orbit around the Sun, or rather the second Lagrange point from the Sun and the Earth - this is the place where the gravitational forces of two objects are balanced, and therefore the third object (in this case, a telescope) can remain motionless. James Webb's telescope is too big to fit into a rocket, so it will fly when folded, and in space it will open like a transforming flower; look at this video to understand how this happens.
After that, he will be able to look farther than any telescope in history: 13 billion light years from Earth. Since light, as you might guess, travels at the speed of light, the objects we see are in the past. Roughly speaking, when you look at a star through a telescope, you see it as it looked tens, hundreds, thousands and so on of years ago. Therefore, the James Webb Telescope will see the first stars and galaxies as they were after the Big Bang. This is very important: we will better understand how galaxies were formed, stars and planetary systems appeared, we will be able to better understand the origin of life. Perhaps the James Webb Telescope will even help us extraterrestrial life. There is one thing: a lot of things can go wrong during the mission, and since the telescope will be very far from Earth, it will be impossible to send it to be repaired, as it was with the Hubble.
What's the practical point of all this?
This is a question that astronomy often asks, especially considering how much money is spent on it. Two answers can be given to it: firstly, not everything, especially science, should have a clear practical meaning. Astronomy and telescopes help us better understand the place of humanity in the Universe and the structure of the world in general. Secondly, astronomy still has practical benefits. Astronomy is directly related to physics: understanding astronomy, we understand physics much better, because there are physical phenomena that cannot be observed on Earth. For example, if astronomers prove the existence of dark matter, this will greatly affect physics. In addition, many technologies invented for space and astronomy are also used in everyday life: You can think of satellites that are now used for everything from television to GPS navigation. Finally, astronomy will be very important in the future: in order to survive, humanity will need to extract energy from the Sun and fossils from asteroids, settle on other planets and, possibly, communicate with alien civilizations - all this will be impossible if we do not develop astronomy and telescopes now ...
There is such a mechanism - a telescope. What is it for? What functions does it perform? How does it help?
general information
Stargazing has been fun for a long time. It was not only a pleasant but also a rewarding pastime. Initially, man could only observe the stars with his own eyes. In such cases, the stars were just points on the firmament. But in the seventeenth century, the telescope was invented. What was it for and why is it used now? In clear weather, it can be used to observe thousands of stars, carefully examine the month, or simply observe the depths of space. But let's say a person is interested in astronomy. The telescope will help him observe tens, hundreds of thousands or even millions of stars. In this case, it all depends on the power of the device used. So, amateur telescopes give a magnification of several hundred times. If we talk about scientific instruments, they can see thousands and millions of times better than we do.
Types of telescopes
Conventionally, two groups can be distinguished:
- Amateur devices. This includes telescopes, the magnification of which is a maximum of several hundred times. Although there are relatively weak devices. So, for observing the sky, you can even buy budget models with a hundredfold increase. If you want to buy such a device for yourself, then know about the telescope - the price for them starts from 5 thousand rubles. Therefore, almost everyone can afford to study astronomy.
- Professional scientific instruments. There is a division into two subgroups: optical and radar telescopes. Alas, the former have a certain rather modest supply of possibilities. In addition, when the threshold of 250x is reached, the picture quality begins to drop sharply due to the atmosphere. The famous Hubble telescope can be cited as an example. It can transmit clear pictures with 5 thousand times magnification. If you neglect the quality, then it can improve visibility by 24,000! But the real miracle is the radar telescope. What is it for? Scientists use it to observe the Galaxy and even the Universe, learning about new stars, constellations, nebulae and others
What does a telescope give a person?
It is your ticket to a truly fantastic world of unexplored starry depths. Even budget amateur telescopes will allow scientific discoveries (even if made earlier by one of the professional astronomers). But a common person can do a lot. So, did the reader know that most comets were discovered by amateurs, not professionals? Some people make a discovery not even once, but many times, naming the found objects as they like. But even if it was not possible to find anything new, then every person with a telescope can feel much closer to the depths of the Universe. With it, you can admire the beauties of other planets of the solar system.
If we talk about our satellite, then it will be possible to carefully consider the relief of its surface, which will be more lively, voluminous and detailed. In addition to the Moon, it will be possible to admire Saturn, the polar cap of Mars, dreaming of how apple trees will grow on it, the beautiful Venus and Mercury, which was blown out by the Sun. This is truly a delightful sight! With a more or less powerful device, it will be possible to observe variable and double massive fireballs, nebulae and even nearby galaxies. True, certain skills are still required to detect the latter. Therefore, it will be necessary to buy not only telescopes, but also educational literature.
The telescope's faithful assistant
In addition to this device, its owner will find another tool for studying space useful - a map of the starry sky. This is a reliable and faithful cheat sheet that helps and facilitates the search for the desired objects. Previously, paper maps were used for this. But now they have been successfully replaced by electronic versions. They are much more convenient to use than printed cards. Moreover, this direction is actively developing, so even a virtual planetarium can provide a significant help to the owner of the telescope. Thanks to them, the required image will be quickly presented on the first request. Among the additional functions of such software - even providing any supporting information that might be useful.
So we figured out what a telescope is, what it is for and what opportunities it provides.
At present, many space telescopes operate in various orbits around the Earth, the Sun and at Lagrange points, covering the entire range of electromagnetic waves from radio to gamma radiation, including the unique and largest in history Russian Radioastron.
Space telescopes can work around the clock, they are excluded from distortion of the atmosphere and weather conditions, most of the discoveries in deep space falls on these observatories.
The best of the devices operating in the radio range in the VLB interferometer mode together with the global terrestrial network of radio telescopes is the Russian Radioastron, which allows obtaining the highest angular resolution in the entire history of astronomy - 21 microseconds of arc. This is more than a thousand times better than the resolution of the Hubble Space Telescope, an optical telescope with such an angular resolution could see a matchbox on the lunar surface.
A space radio telescope with a receiving parabolic antenna 10 meters in diameter was launched on July 18, 2011 by a Zenit-3SLBF launch vehicle into a high-apogee orbit of an Earth satellite up to 340 thousand km high as part of the Spektr-R spacecraft. It is the world's largest space telescope, which was noted in the Guinness Book of Records.
The main types of objects studied are quasars, neutron stars and black holes. IN new program by the end of 2018 - studies of the inner regions of the nuclei of active galaxies and their magnetic fields, tracking the brightest quasars, studying water vapor clouds in the Universe, pulsars and the interstellar medium, a gravitational experiment.
Recently, scientific data have been obtained on the discovery of the extreme brightness of the core of the quasar 3C273 in the constellation Virgo, it has a temperature of 10 to 40 trillion degrees. In the image of the quasar, it was possible to discern inhomogeneities - bright specks that appeared "in the transmission" when radiation passed through the interstellar medium of the Milky Way.
For the first time, astrophysicists were able to study the structures associated with processes in a supermassive black hole at the center of our Galaxy.
In the microwave range best results were received by the Planck Observatory of the European Space Agency, which operated until 23 October 2013. The main mirror 1.9 × 1.5 m in size is tilted with respect to the incoming beam, the telescope aperture is 1.5 m. Planck made observations from the L2 Lagrange point of the Sun-Earth system at a distance of 1,500,000 km.
The main task was to study the distribution of intensity and polarization relict radiation with high resolution.
According to Planck, the world consists of 4.9% of ordinary (baryonic) matter, 26.8% of dark matter and 68.3% of dark energy.
The Hubble constant has been refined, the new value is H0 \u003d 68 km / s / Mpc, that is, 13.80 billion years have passed since the big bang.
From the analysis of the data obtained, it was possible to more confidently establish the number of types of neutrinos - three types (electron, muon and tau neutrinos).
“Planck” confirmed the presence of a slight difference in the spectrum of initial perturbations of matter from a homogeneous one, which is an important result for the inflationary theory, which is today the fundamental theory of the first moments of the life of the Universe.
In the infrared range, the largest was the European Space Agency's Herschel telescope, with a 3.5-meter mirror, launched by the Ariane 5 launch vehicle simultaneously with the Planck Observatory to the L2 Lagrange point. It operated until June 17, 2013, when 2300 kg of liquid helium were used up to cool the infrared CCD array.
The formation and development of galaxies in the early Universe were studied; chemical composition atmospheres and surfaces of bodies in the solar system, including planets, comets and planetary satellites. The main object of research was the formation of stars and their interaction with the interstellar medium. Many beautiful images of galactic gas nebulae have been taken.
In the molecular cloud W3, located at a distance of 6,200 light-years from Earth, you can see the yellow dots, which are low-mass protostars. More massive "embryos" of the luminaries are colored in the picture with blue light, corresponding to their more high temperature.
Among optical telescopes, the largest, most famous and honored is the NASA and European Space Agency Hubble Space Telescope with a 2.4-meter main mirror, launched by the Discovery shuttle on April 24, 1990, into orbit around the Earth at an altitude of 569 km. After five maintenance operations carried out during the space shuttle expeditions, it continues to work today.
The Edwin Hubble Telescope has taken thousands of pictures of the planets of the solar system
Planetary systems of some nearby stars have been explored
The most beautiful and unusual pictures of gas nebulae
Distant galaxies have shown their extraordinary beauty.
The already mentioned close quasar 3C273 with a jet escaping from the center:
In this image, with a total exposure time of 2 million seconds, there are about 5,500 galaxies, the farthest of which is 13.2 billion light years distant from us, the youngest galaxy captured in the image was formed just 600 million years after the Big Bang ...
In the ultraviolet wavelength range, the largest was and remains the Hubble, and the largest specialized ultraviolet telescope was the Soviet Astron observatory with a main mirror 0.8 m in diameter, launched on March 23, 1983 by the Proton launch vehicle into an elongated orbit - from 19015 km to 185,071 km around the Earth and worked until 1989.
In terms of the number of results, Astron is considered one of the most successful space projects. Spectra were obtained for over a hundred stars of various types, about thirty galaxies, dozens of nebulae and background regions of our Galaxy, as well as several comets. The study of non-stationary phenomena (emissions and absorption of matter, explosions) in stars, the phenomena key to understanding the formation of gas and dust nebulae. Comet Halley's coma was observed from 1985 to 1986, and supernova 1987A in the Large Magellanic Cloud.
Ultraviolet images of the Cygnus Loop taken by the Hubble Telescope:
Among the X-ray observatories, the Chandra space telescope stands out, the AXAF / Chandra take-off mass was 22,753 kg, which is an absolute record for the mass ever launched into space by space shuttles by space shuttles, launched on July 23, 1999 by the space shuttle Columbia into an extended orbit - from 14304 km to 134528 km around the Earth, it is still in effect.
Observations by the Chandra Observatory in the Crab Nebula were able to distinguish shock waves around the central pulsar, which until now were invisible to other telescopes; managed to distinguish X-rays from a supermassive black hole in the center Milky way; a new type of black hole was discovered in the galaxy M82, which has become the missing link between stellar mass black holes and supermassive black holes.
Evidence for the existence of dark matter was discovered in 2006 by observing collisions of superclusters of galaxies.
The international gamma-ray telescope Fermi with a mass of 4303 kg, launched on June 11, 2008 by the Delta-2 launch vehicle into an orbit with an altitude of 550 km, continues to operate in the gamma range.
The observatory's first significant discovery was the registration of a gamma-ray pulsar located in the supernova remnant CTA 1.
Since 2010, the telescope has recorded several powerful gamma-ray bursts from new stars. Such gamma-ray bursts occur in closely related binaries when matter accretes from one star to another.
One of the most amazing discoveries made by the space telescope was the discovery of giant formations up to 50 thousand light years across, located above and below the center of our Galaxy, which arose due to the activity of a supermassive black hole in the center of the Galaxy.
In October 2018, the James Webb Space Telescope with a main mirror 6.5 meters in diameter is planned to be launched using the Ariane 5 rocket. It will operate at the Lagrange point in the optical and infrared ranges, significantly surpassing the capabilities of the Hubble Space Telescope.
The Lavochkin Scientific and Production Association is working on the Millimetron (Spectrum-M) space observatory of millimeter and infrared wavelengths with a cryogenic telescope with a diameter of 10 m. The telescope in its characteristics will exceed by orders of magnitude those of similar Western predecessors.
One of the most ambitious projects of Roscosmos, the launch of which was planned after 2019, is at the stage of layouts, design drawings and calculations.
Impossible to get. That is why telescopes are launched into space.
All these devices have different "vision". Some types of telescopes study space objects in the infrared and ultraviolet range, while others in the X-ray range. This is the reason for the creation of more and more perfect space systems for deep learning.
Hubble Space Telescope
Kepler Telescope
The Kepler Telescope was launched by NASA on March 6, 2009. Its special purpose is to search for exoplanets. The tasks of the telescope include observing the brightness of more than 100 thousand stars for 3.5 years, during which it must determine the number of planets, similar, located at a suitable distance for the emergence of life from their suns. Compile a detailed description of these planets and the shapes of their orbits, study the properties of stars with planetary systems, and much more. To date, "Kepler" has already identified five star systems and hundreds of new planets, 140 of which are similar in characteristics to
The Transiting Exoplanet Survey Satellite (TESS) is an upcoming NASA mission that surveys about 200,000 stars for signs of exoplanets.
On a note! Exoplanets, or extrasolar planets, are planets outside the solar system. For a long time, the study of these celestial objects was inaccessible to researchers - unlike stars, they are too small and dim.
NASA has dedicated an entire program to the search for exoplanets with conditions similar to Earth. It consists of three stages. Principal Investigator, George Reeker of the Institute of Astrophysics and space exploration them. Kavli, called the project “the mission of the century”.
The satellite was proposed as a mission in 2006. The startup was sponsored by such well-known companies as the Kavli Foundation, Google, and the initiative was also supported by the Massachusetts Institute of Technology.
In 2013, TESS was included in the NASA Explorer program. TESS is designed for 2 years. It is expected that in the first year spacecraft will explore the Southern Hemisphere, the second - the Northern Hemisphere.
"TESS foresees the discovery of thousands of exoplanets of all sizes, including dozens of Earth-size comparable ones," the Massachusetts statement said in a statement. institute of Technology (MIT), who leads the mission.
Aims and purposes of the telescope
The satellite is a follow-up to NASA's successful Keppler Space Telescope mission, launched in 2009.
Like Kepler, TESS will search for changes in the brightness of the stars. When an exoplanet passes in front of a star (called a transit), it partially obscures the light emitted by the star.
These dips in brightness may indicate that one or more planets are orbiting the star.
However, unlike Keppler, the new mission will focus on stars 100 times brighter, select the most suitable for detailed study, and define targets for future missions.
TESS will scan the sky divided into 26 sectors with an area of \u200b\u200b24 by 96 degrees. Powerful cameras on spaceship will record the slightest change in the light of the stars in each sector.
Project manager Riker noted that the team expects to discover several thousand planets during the mission. “This task is broader, it goes beyond detecting exoplanets. Images from TESS will allow a number of discoveries in astrophysics, ”he added.
Features and characteristics
The TESS telescope is more advanced than its predecessor, Keppler. They have the same goal, both use a "transit" search technique, but the possibilities are different.
Having recognized more than two thousand exoplanets, Keppler spent his main mission observing a narrow section of the sky. TESS has a field of view that is almost 20 times larger, which allows it to detect more celestial objects.
The next baton in the study of exoplanets will be taken by the space telescope James Webb.
Webb will scan objects identified by TESS in more detail for water vapor, methane and other atmospheric gases. It is planned to be launched into orbit in 2019. This mission should be final.
Equipment
According to NASA, the solar-powered spacecraft carries four wide-angle optical telescopes - refractors. Each of the four devices has built-in semiconductor cameras with a resolution of 67.2 megapixels, which are capable of operating in the spectral range from 600 to 1000 nanometers.
Modern equipment should provide a wide view of the entire sky. The telescopes will observe a specific area in the interval from 27 to 351 days and then move on to the next, sequentially traversing both hemispheres for two years.
Monitoring data will be processed and stored on board the satellite for three months... The device will transmit to Earth only those data that may be of scientific interest.
Orbit and launch
One of the most difficult tasks for the team was calculating the unique orbit for the spacecraft.
The device will be launched into a high elliptical orbit around the Earth - it will circumnavigate the Earth twice during the time the Moon completes a full circle. This type of orbit is the most stable. There is no space debris and strong radiation that could disable the satellite. The device will easily exchange data with ground services.
Launch dates
However, there is also a minus - such a trajectory limits the timing of the launch: it must be synchronized with the moon's orbit. The ship has a small "window" - from March to June - missing this deadline, the mission will not be able to complete the planned tasks.
- According to the published NASA budget, the maintenance of the exoplanetary telescope in 2018 will cost the agency almost $ 27.5 million, with a total project cost of $ 321 million.
- The spacecraft will rotate in an orbit that has never been used before. An elliptical orbit, called P / 2, is exactly half the Moon's orbital period. This means that TESS will orbit the Earth every 13.7 days.
- For the right to launch the satellite, the aerospace corporation Elon Musk has withstood serious competition with Boeng. Statistics and NASA were on the side
- The development of instruments - from airborne telescopes to optical receivers - was funded by Google.
TESS is expected to find thousands of candidates for the title of exoplanet. This will help astronomers better understand the structure of planetary systems and give an idea of \u200b\u200bhow our solar system formed.