What is a telescope brief definition. Telescope "James Webb" - the most powerful telescope in the world (28 photos)

The sky beckons us when we look at its open spaces. What is hidden behind the clouds, and what is in its impenetrable darkness? Of course, we were able to get some idea of ​​these questions with the help of a telescope. Undoubtedly, this is a unique device that gave us a magnificent picture of space. And undoubtedly, it brought our understanding of the heavenly space closer.

It is known that the first telescope was created by Galileo Galilei. Although few people know that he used the early discoveries of other scientists. For example, the invention of the telescope for navigation.
In addition, glass craftsmen have already created glasses. In addition, lenses were used. And the effect of refraction and magnification of glass has been more or less studied.

Of course, Galileo achieved a significant result in the study of this area. In addition, he collected and improved all the developments. And as a result, he developed and introduced the world's first telescope. In truth, it only had a threefold increase. But it was distinguished by high image quality at that time.

By the way, it was Galileo who called his developed object a telescope.
In the future, the scientist did not stop there. He improved the device up to twenty times the image magnification.
It is important that Galileo not only developed the telescope. Moreover, he was the first to use it for space exploration. In addition, he made a lot of astronomical discoveries.

Telescope characteristics

The telescope consists of a tube that stands on a special mount. It is equipped with axes for aiming at the observed object.
In addition, the optical device has an eyepiece and a lens. Moreover, the rear plane of the lens is perpendicular to the optical axis, and is connected to the front surface of the eyepiece. Which, by the way, is similar to the objective in relation to the optical axis.

It is worth noting that a special device is used for focusing.
The main characteristics of telescopes are magnification and resolution.
Image magnification depends on the focal length of the eyepiece and the object.
Resolution is related to the refraction of light. Thus, the size of the observed object is limited by the resolution of the telescope.

Types of telescopes in astronomy

The varieties of telescopes are associated with different construction methods. More precisely, the use of various tools as a lens. In addition, it matters for what purpose the device is needed.
Today, there are several main types of telescopes in astronomy. Depending on the light-harvesting component, they are lens, mirror and combined.

Lens telescopes (diopter)

In other words, they are called refractors. These are the very first telescopes. In them, light is collected by a lens, which is bounded by a sphere on both sides. Therefore, it is considered biconvex. In addition, the lens is a lens.
Interestingly, you can use not just a lens, but a whole system of them.

It is worth noting that convex lenses refract light rays and bring them into focus. And in it, in turn, an image is built. An eyepiece is used to view it.
What is important, the lens is set so that the focus and the eyepiece coincide.
By the way, Galileo invented the refractor. But modern devices consist of two lenses. One of them collects light, and the other scatters. That allows to reduce deviations and errors.

Mirror telescopes (cataptric)

They are also called reflectors. Unlike the lens type, their lens is a concave mirror. It collects starlight at one point and reflects it to the eyepiece. In this case, the errors are minimal, and the decomposition of light into rays is completely absent. But the use of a reflector limits the field of view of the observer.
Interestingly, mirror telescopes are the most common in the world. Because their development is much easier than, for example, lens devices.

Catadioptric telescopes (combined)

These are mirror lenses. They use both lenses and mirrors to produce images.

In turn, they were divided into two subspecies:
1) Schmidt-Cassegrain telescopes - they have a diaphragm installed in the very center of the curvature of the mirror. This eliminates spherical disturbances and deviations. But the field of view and image quality increase.
2) Maksutov-Cassegrain telescopes - a plano-convex lens is installed in the region of the focal plane. As a result, field curvature and spherical deflection are prevented.

It should be noted that in modern astronomy, it is the combined type of instruments that is most often used. By mixing two different elements to collect light, they produce better data.

Such devices are capable of receiving only one wave of signals. Antennas transmit signals and process them into images.
Radio telescopes are used by astronomers for scientific research.

Infrared telescope models

They are very similar in design to optical mirror telescopes. The principle of obtaining an image is almost the same. The rays are reflected by the lens and are collected at one point. Next, a special device measures the heat and photographs the result.

Modern telescopes

A telescope is an optical instrument for observation. It was invented almost half a century ago. During this time, scientists changed and improved the device. Indeed, many new models have been created. Unlike the first ones, they have an increased quality and an increase in the image.

In our age of technology, computer telescopes are used. Accordingly, they are equipped with special programs. What is important, the modern prototype takes into account that each person's perception of the eyes is different. For high accuracy, the image is transmitted to the monitor. Thus, the image is perceived as it really is. In addition, this method of observation eliminates any distortion.

In addition, scientists of our generation use not one device at the same time, but several. Moreover, unique cameras are connected to the telescope, which transmit information to a computer. This allows you to get clear and accurate information. Which, of course, are used to study and.

Interestingly, now telescopes are not just instruments for observation. But also devices for measuring distances between space objects. For this function, spectrographs are connected to them. And the interaction of these devices provides specific data.

Other classification

There are also other types of telescopes. But they are used for their own purpose. For example, X-ray and gamma-ray telescopes. Or ultraviolet devices that filter the picture without processing and exposure.
In addition, devices can be divided into professional and amateur. The former are used by scientists and astronomers. Obviously, the latter are suitable for home use.

How to choose a telescope for astronomy lovers

Choosing a telescope for astronomy enthusiasts is based on what you want to observe. In principle, the types and characteristics of devices are described above. You just need to choose which one you like best. It is better, in my opinion, to dwell on a lens or a combined form. But the choice, of course, is yours.

According to the Internet, the best amateur telescopes are represented by companies: Celestron, Bresser and Veber.

The telescope has been studying the life of planets for hundreds of years

The creation and development of the telescope, in fact, made it possible to make a huge step in space exploration. Probably everything we know was formed with the help of this device. Although, of course, one should not underestimate the very activities of scientists.
Today we looked at some types of telescopes and their characteristics. Definitely, the progress of technology is visible. And as a result, we learned a lot of interesting things about space objects and space itself. In addition, we can admire the beautiful sky and get to know it thanks to this wonderful invention.

Optical telescopic systems are used in astronomy (to observe celestial bodies), in optics for various auxiliary purposes: for example, to change the divergence of laser radiation. Also, the telescope can be used as a spotting scope, to solve the problems of observing distant objects. The very first drawings of the simplest lens telescope were found in the notes of Leonardo Da Vinci. Built a telescope at Lippershey. Also, the creation of the telescope is attributed to his contemporary Zachary Jansen.

Story

The year of the invention of the telescope, or rather the telescope, is considered 1608, when the Dutch spectacle master John Lippershey demonstrated his invention in The Hague. Nevertheless, he was denied a patent due to the fact that other masters, like Zakhary Jansen from Middelburg and Jakob Metius from Alkmaar, already possessed copies of telescopes, and the latter, shortly after Lippershey, submitted a request to the States General (Dutch Parliament) for patent . Later research showed that spyglasses were probably known earlier, as early as 1605. In "Additions to Vitellia", published in 1604, Kepler considered the path of rays in an optical system consisting of a biconvex and biconcave lenses. The very first drawings of the simplest lens telescope (both single-lens and two-lens) were found in the notes of Leonardo da Vinci, dated 1509. His entry has been preserved: “Make glasses to look at full moon"(The Atlantic Code).

The first to send spotting scope into the sky, turning it into a telescope, and received new scientific data, became Galileo. In 1609, he created his first 3x telescope. In the same year, he built a telescope with an eightfold magnification, about half a meter long. Later, he created a telescope that gave a 32-fold increase: the length of the telescope was about a meter, and the diameter of the lens was 4.5 cm. It was a very imperfect instrument that had all possible aberrations. Nevertheless, with his help, Galileo made a number of discoveries.

The name "telescope" was proposed in 1611 by the Greek mathematician Ioannis Dimisianos (Giovanni Demisiani-Giovanni Demisiani) for one of Galileo's instruments, shown at the out-of-town symposium of the Accademia dei Lincei. Galileo himself used the term lat for his telescopes. perspicillum.

Telescope of Galileo, Museum of Galileo (Florence)

The 20th century also saw the development of telescopes that operated over a wide range of wavelengths from radio to gamma rays. The first specially designed radio telescope was commissioned in 1937. Since then, a huge variety of sophisticated astronomical instruments have been developed.

Optical telescopes

The telescope is a tube (solid, frame) mounted on a mount equipped with axes for pointing at the object of observation and tracking it. A visual telescope has a lens and an eyepiece. The rear focal plane of the objective is aligned with the front focal plane of the eyepiece. Instead of an eyepiece, a photographic film or a matrix radiation detector can be placed in the focal plane of the lens. In this case, the telescope lens, from the point of view of optics, is a photographic lens, and the telescope itself turns into an astrograph. The telescope is focused using a focuser (focusing device).

According to their optical design, most telescopes are divided into:

• Lens ( refractors or diopter) - a lens or a system of lenses is used as a lens.
• Mirrored ( reflectors or cataptric) - a concave mirror is used as a lens.
• Mirror-lens telescopes (catadioptric) - usually a spherical main mirror is used as an objective, and lenses are used to compensate for its aberrations.

radio telescopes

Very Large Array radio telescopes in New Mexico, USA

Radio telescopes are used to study space objects in the radio range. The main elements of radio telescopes are a receiving antenna and a radiometer - a sensitive radio receiver, tunable in frequency, and receiving equipment. Since the radio range is much wider than the optical range, various designs of radio telescopes are used to detect radio emission, depending on the range. In the long-wavelength region (meter range; tens and hundreds of megahertz), telescopes are used that are composed of a large number (tens, hundreds or even thousands) of elementary receivers, usually dipoles. For shorter waves (decimeter and centimeter range; tens of gigahertz), semi- or full-rotation parabolic antennas are used. In addition, to increase the resolution of telescopes, they are combined into interferometers. When combining several single telescopes located in different parts of the globe into a single network, one speaks of very long baseline radio interferometry (VLBI). An example of such a network is the American VLBA (Very Long Baseline Array) system. From 1997 to 2003, the Japanese orbiting radio telescope HALCA (eng. Highly Advanced Laboratory for Communications and Astronomy) included in the network of VLBA telescopes, which significantly improved the resolution of the entire network. The Russian orbital radio telescope RadioAstron is also planned to be used as one of the elements of the giant interferometer.

space telescopes

The earth's atmosphere well transmits radiation in the optical (0.3-0.6 microns), near infrared (0.6-2 microns) and radio (1 mm - 30) ranges. However, as the wavelength decreases, the transparency of the atmosphere is greatly reduced, as a result of which observations in the ultraviolet, x-ray and gamma ranges become possible only from space. An exception is the registration of ultrahigh-energy gamma radiation, for which the methods of cosmic ray astrophysics are suitable: high-energy gamma-ray photons in the atmosphere give rise to secondary electrons, which are registered by ground-based facilities using the Cherenkov glow. An example of such a system is the CACTUS telescope.

Atmospheric absorption is also strong in the infrared range, however, in the 2-8 µm region there are a number of transparency windows (as well as in the millimeter range) in which observations can be made. In addition, since most of the absorption lines in the infrared range belong to water molecules, infrared observations can be made in dry regions of the Earth (of course, at those wavelengths where transparency windows form due to the absence of water). An example of such a placement of a telescope is the South Pole Telescope. South Pole Telescope), installed at the geographic south pole, operating in the submillimeter range.

In the optical range, the atmosphere is transparent, however, due to Rayleigh scattering, it transmits light of different frequencies in different ways, which leads to a distortion of the spectrum of the stars (the spectrum shifts towards red). In addition, the atmosphere is always inhomogeneous, there are constant currents (winds) in it, which leads to image distortion. Therefore, the resolution of terrestrial telescopes is limited to approximately 1 arc second, regardless of the aperture of the telescope. This problem can be partially solved by using adaptive optics, which can greatly reduce the influence of the atmosphere on image quality, and by raising the telescope to a higher altitude, where the atmosphere is more rarefied - into the mountains, or into the air on airplanes or stratospheric balloons. But the greatest results are achieved with the removal of telescopes into space. Outside the atmosphere, distortions are completely absent, therefore the maximum theoretical resolution of the telescope is determined only by the diffraction limit: φ=λ/D (angular resolution in radians is equal to the ratio of the wavelength to the aperture diameter). For example, the theoretical resolution of a space telescope with a mirror 2.4 meters in diameter (like the Hubble telescope) at a wavelength of 555 nm is 0.05 arc seconds (the real Hubble resolution is two times worse - 0.1 seconds, but still an order of magnitude higher than that of terrestrial telescopes ).

Removal into space allows you to increase the resolution of radio telescopes, but for a different reason. Each radio telescope itself has a very small resolution. This is explained by the fact that the length of radio waves is several orders of magnitude greater than that of visible light, so the diffraction limit φ=λ/D is much larger, even though the size of a radio telescope is also tens of times larger than that of an optical one. For example, with an aperture of 100 meters (there are only two such large radio telescopes in the world), the resolution at a wavelength of 21 cm (neutral hydrogen line) is only 7 arc minutes, and at a length of 3 cm - 1 minute, which is completely insufficient for astronomical research ( for comparison, the resolution of the naked eye is 1 minute, the apparent diameter of the Moon is 30 minutes). However, by combining two radio telescopes into a radio interferometer, the resolution can be substantially increased - if the distance between the two radio telescopes (the so-called radio interferometer base) is equal to L, then the angular resolution is no longer determined by the formula φ=λ/D, but φ=λ/L. For example, at L=4200 km and λ=21 cm, the maximum resolution will be about one hundredth of an arc second. However, for terrestrial telescopes, the maximum base cannot obviously exceed the diameter of the Earth. By launching one of the telescopes into deep space, one can significantly increase the base, and hence the resolution. For example, the resolution of the RadioAstron space telescope, when working together with the terrestrial radio telescope in the radio interferometer mode (base 390 thousand km), will be from 8 to 500 microseconds of arc, depending on the wavelength (1.2-92 cm). (for comparison - at an angle of 8 μs, an object 3 m in size is visible at a distance of Jupiter, or an object the size of the Earth at a distance

The one who invented the telescope undoubtedly deserves respect and great gratitude from all modern astronomers. This is one of the greatest discoveries in history. The telescope made it possible to study near space and learn a lot about the structure of the universe.

How it all started

The first attempts to create a telescope are attributed to the great Leonardo da Vinci. There are no patents or references to a working model, but scientists have found the remains of drawings and descriptions of glasses for looking at the moon. Perhaps this is another myth about this unique person.

The telescope device came to mind to Thomas Digges, who tried to create it. He used convex glass and a concave mirror. By itself, the invention could work, and, as history will show, such a device will be created again. But technically there were still no means to implement this idea, he did not manage to create a working model. The developments remained unclaimed at that time, and Digges entered the history of astronomy for describing

thorny path

In what year the telescope was invented is still a moot point. In 1609, the Dutch scientist Hans Lippershey presented his magnifying invention to the patent office. He named it. But the patent was rejected due to excessive simplicity, although the spyglass itself came into common use. It gained particular popularity among sailors, but for astronomical needs it turned out to be rather weak. A step forward has already been taken.

In the same year, it fell into the hands of Thomas Hariot, he liked the invention, but needed a significant revision of the original sample. Thanks to his work, astronomers were able to see for the first time that the moon has its own relief.

Galileo Galilei

Having learned about the attempt to create a special device for magnifying stars, Galileo really got excited about this idea. The Italian decided to create a similar design for his research. Mathematical knowledge helped him with calculations. The device consisted of a tube and lenses inserted into it, made for people with poor eyesight. In fact, this was the first telescope.

Today, this type of telescope is called refractor. Thanks to the improved design, Galileo made many discoveries. He managed to prove that the moon has the shape of a sphere, saw craters and mountains on it. A 20x magnification made it possible to see 4 rings on Saturn and much more. At that time, the device turned out to be the most advanced device, but it had its drawbacks. The narrow tube significantly reduced the field of view, and the distortions obtained due to the large number of lenses made the picture blurry.

The era of refracting telescopes

It will not be possible to clearly answer the question of who first invented the telescope, because Galileo only improved the already existing pipe for contemplating the sky. Without Lippershey's idea, this idea might not have occurred to him. In subsequent years, there was a gradual improvement of the device. Development was significantly hampered by the impossibility of creating large lenses.

The impetus for further development was the invention of the tripod. The pipe now did not have to be held in hands for a long time. This made it possible to lengthen the tube. Christian Huygens in 1656 presented an apparatus with a magnification of 100 times, this was achieved by increasing the distance between the lenses, which were placed in a tube 7 meters long. After 4 years, a telescope 45 meters long was created.

Even a slight wind could interfere with research. They tried to reduce the distortion of the picture by further increasing the distance between the lenses. The development of telescopes has gone in the direction of elongation. The longest of them reached 70 meters. This state of affairs greatly hampered the work, and the very assembly of the device.

New principle

The development of space optics came to a standstill, but it could not continue like this for a long time. Who invented the fundamentally new telescope? It was one of the greatest scientists of all time - Isaac Newton. Instead of a lens for focusing, a concave mirror was used, which made it possible to get rid of chromatic distortions. Refracting telescopes are a thing of the past, rightfully giving way to reflex telescopes.

The discovery of a telescope operating on the principle of a reflector turned astronomical science upside down. The mirror used in the invention, Newton had to make himself. For its manufacture, an alloy of tin, copper and arsenic was used. The first working model continues to be stored to this day, the London Museum of Astronomy has become its haven. But there was a small problem. Those who invented the telescope for a long time could not create an ideally shaped mirror.

Breakthrough

The year 1720 became a significant date for all astronomical science. It was this year that opticians managed to create a reflex mirror with a diameter of 15 cm. By the way, Newton's mirror had a diameter of only 4 cm. It was a real breakthrough, it became much easier to penetrate the secrets of the universe. Miniature telescopes compared to 40-meter giants were only 2 meters long. Space observation has become available to a larger circle of people.

Compact and convenient telescopes could become fashionable for a long time, if not for one "but". The metal alloy quickly dimmed and thereby lost its reflective properties. Soon the mirror design was improved and acquired new features.

two mirrors

The next improvement of the telescope device is due to the Frenchman Cassegrain. He came up with the idea of ​​using 2 glass mirrors instead of one made of a metal alloy. His drawings turned out to be working, but he himself could not be convinced of this, the technical equipment did not allow him to realize his dream.

The telescopes of Newton and Cassegrain can already be considered the first modern models. On their basis, the development of telescope construction is now continuing. According to the Cassegrain principle, the modern Hubble space telescope has been built, which has already brought a lot of information to mankind.

Back to basics

The Reflectors could not finally win. Refractors triumphantly returned to the pedestal with the invention of two new types of glass: crown - lighter, and flint - heavy. This combination came to the aid of the one who invented the telescope without achromatic errors. It turned out to be a talented scientist J. Dollond, and it was named after him. the new kind lens - dollar.

In the 19th century, the refractor telescope experienced its second birth. With the development of technical thought, it became possible to produce lenses of an ideal shape and ever larger sizes. In 1824, the diameter of the lens was 24 cm, by 1966 it had grown into two cuts, and in 1885 it was already 76 centimeters. Relatively speaking, the diameter of the lens grew by about 1 cm per year. They almost forgot about mirror devices, while lens devices now grew not in length, but in the direction of increasing diameter. This made it possible to improve the viewing angle and at the same time enlarge the picture.

Great Enthusiasts

Reflex installations were revived by amateur astronomers. One of them was William Herschel, despite the fact that his main occupation is music, he made many discoveries. His very first discovery was the planet Uranus. Unprecedented success inspired him to create a larger diameter telescope. Having created a mirror with a diameter of 122 cm in his home laboratory, he was able to consider 2 previously unknown ones.

The successes of amateurs pushed for new experiments. The main problem of metal mirrors - rapid clouding - has not been overcome. This led the French physicist Léon Foucault to the idea of ​​inserting another mirror into the telescope. In 1856, he made a silver-coated glass mirror for a magnifying device. The result exceeded the wildest forecasts.

Another important addition was made by Mikhail Lomonosov. He changed the system so that the mirror began to rotate independently of the lens. This made it possible to minimize the loss of light waves and adjust the image. At the same time, Herschel announced a similar discovery.

Now both designs are actively used, and the improvement of optics continues. Modern computers come into play, and the largest telescope on Earth is the Great Canary Telescope. But soon its greatness will be eclipsed, projects with mirrors with a diameter of 30 m against its 10.4 m are already in the works.

Giant telescopes are built on a hill in order to exclude as much as possible the refraction of the image by the earth's atmosphere. A promising direction is the construction of space telescopes. They give the clearest picture with maximum resolution. All this would have been impossible if a telescope had not been created in the distant 17th century.

What is a telescope? In 1608, the Dutch optician Hans Lippershey invented the telescope, a device used by astronomers to magnify images of distant objects.

He noticed that these objects seem closer when viewed through two spectacle lenses, and placed the lenses in the tube. This is how the first telescope was born.

It is possible that primitive telescopes and spyglasses appeared even earlier, but Lippershey is said to have been the first to use appropriate devices to purposefully look behind celestial bodies.

Who Invented the Telescope?

Some are inclined to believe that the telescope invented. In fact, the great scientist only improved the Dutchman H. Lippershey, who appeared in 1608, and the name "telescope" was given to the Greek I. Demisiani in 1611, when he became acquainted with Galileo's instrument.

The results of using even the simplest optical telescopes were simply amazing: they were discovered on , spots on , individual at .

Galileo's telescope, like all such instruments in the future, consisted of two parts. Lens - optical lens- collected light, and the researcher examined the resulting image through an eyepiece - a kind of magnifying glass that allows you to enlarge the image.

So, the second telescope, built by Galileo, enlarged the images of celestial bodies by 34 times. Optical instruments in which the image is obtained using a converging lens are called refractors - from the Latin word "refraction", meaning "refract".

Refracting telescopes had one serious drawback - they could not greatly increase the size of the objective, since it is very difficult to make large and high-quality lenses.

In addition, it turned out that the lenses of telescopes refract rays differently. different color, due to which distortions appear in the images - aberrations. To get rid of this, the designs had to be complicated by using compound lenses.

The terrestrial, which introduced its own distortions into observations, also annoyed astronomers a lot. In order not to depend on the state of the atmosphere and, observatories began to be built in the mountains, where the air is transparent for the most part.

Newtonian mirror and refractors

To get rid of color aberration, around 1667 he proposed a fundamentally different scheme of the telescope - in his instrument, the light was collected not by a lens, but by a concave (parabolic) one.

The beam of rays was then directed to a small flat mirror located at the focus of a large mirror, and from there to the eyepiece.

The manufacture of "concave" mirrors is technically simpler, and this immediately made it possible to increase the size and resolution of telescopes. And today, most optical telescopes, including the largest in the world, are refractors.

The largest observatories compete with each other, increasing the size of telescope mirrors. A modern reflector is a complex structure that occupies an entire building and is controlled by a set of .

The most powerful telescope in Eurasia was built in Russia - it is located in the North Caucasus. Its primary mirror is 6 m in diameter and took more than two years to make.

But the "king" of all astronomical instruments located on today is the Great Canary Telescope, built in the Canary Islands by the project of scientists, Spain and.

Its mirror has a diameter of 10.4 m. It is able to "distinguish" objects a billion times fainter than the eye can see.

Modern optical telescopes, made using glass, lenses or mirrors, magnify 100 million times more than Galileo's telescope.

The world's largest optical and infrared twin telescope is installed at the Keck Observatory in Hawaii (pictured). Each of these two eight-story telescopes weighs 300 tons.

The Hubble Space Telescope, named after and launched into orbit in 1990, circles the Earth at a speed of 8 km/s and transmits the received images to the Earth.

Because it is located outside the atmosphere (it distorts and blocks the light that reaches the Earth), a space telescope is able to provide sharper images than telescopes mounted on the earth's surface.

infrared telescopes

Like optical telescopes, the main part of infrared telescopes is the mirror.

It does not have to be as accurate as ground-based reflectors, but interference protection for infrared telescopes is almost the main condition.

And there are many interferences - infrared rays are emitted by all moving and testing parts of the telescope, electronic devices and devices. Therefore, even under conditions, infrared telescopes have to be cooled with liquid helium at a temperature of -270 °C.

The universe is full of sources of infrared radiation - these are the stars themselves, cosmic and, heated by stars located close to them, by super-powerful infrared radiation, you can recognize areas in which new stars are formed.

And even areas close to us, planets and their satellites are explored with the help of infrared instruments, which make it possible to determine the composition and structure of their atmospheres.

Of particular interest to study in the infrared range are the active nuclei of galaxies, the radiation power from which is so high that no explanation has yet been found for this phenomenon.

According to the National Aeronautics and Space Agency (NASA), which is responsible for space research on behalf of the US government, the Hubble Space Telescope transmits about 120 gigabits of scientific data back to Earth every week.

This amount of information is equivalent to the contents of a bookshelf about 1100 m long. A constantly growing collection of images and data is stored on magneto-optical disks.

The Hubble Space Telescope played a pivotal role in the discovery of dark energy, the mysterious force that is accelerating the expansion of the universe.

He discovered protoplanetary disks, clumps of gas and dust around young stars that likely serve as the material from which new planets form.

The Hubble telescope also found that in distant galaxies there are flashes that accompany the death of massive stars - unusual, incredibly powerful bursts of energy.