The Transiting Exoplanet Survey Satellite (TESS for short) is NASA's upcoming mission that will survey some 200,000 stars for signs of exoplanets.
On a note! Exoplanets, or extrasolar planets, are planets outside the solar system. The study of these celestial objects has long been inaccessible to researchers - unlike the stars, they are too small and dim.
The search for exoplanets with conditions similar to the Earth, NASA has devoted a whole program. It consists of three stages. Principal Investigator, George Reeker of the Institute for Astrophysics and Space Research. 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 Massachusetts Institute of Technology also supported the initiative.
In 2013, TESS was included in the NASA Explorer program. TESS is designed for 2 years. It is expected that in the first year the spacecraft will explore the Southern Hemisphere, in the second - the Northern Hemisphere.
"TESS envisions the discovery of thousands of exoplanets of all sizes, including dozens comparable in size to Earth," the Massachusetts Institute of Technology (MIT), which leads the mission, said in a statement.
Goals and objectives of the telescope
The satellite is an extension of the successful mission of NASA's Keppler Space Telescope, launched in 2009.
Like Kepler, TESS will search based on 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 revolve around the star.
However, unlike Keppler, the new mission will focus on stars 100 times brighter, select those most suitable for detailed study, and identify targets for future missions.
TESS will scan the sky divided into 26 sectors of 24 by 96 degrees. Powerful cameras on the spacecraft will capture the slightest changes in starlight in every sector.
Project manager Riker noted that during the mission, the team expects to discover several thousand planets. “This task is broader, it goes beyond the detection of exoplanets. Images from TESS will make a number of discoveries in astrophysics,” he added.
Features and characteristics
The TESS telescope is more advanced than its predecessor, the Keppler telescope. They have the same goal, both use a "transit" search technique, but the possibilities are different.
Recognizing more than two thousand exoplanets, Keppler spent his main mission observing a narrow patch of the sky. TESS has a field of view almost 20 times larger, which allows it to detect more celestial objects.
The next baton in the study of exoplanets will be the James Webb Space Telescope.
Webb will scan objects identified by TESS in greater detail for water vapour, methane and other atmospheric gases. It is scheduled to be put into orbit in 2019. This mission should be the final one.
Equipment
According to NASA, the solar-powered spacecraft has four wide-angle optical telescopes called 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 particular region for between 27 and 351 days and then move on to the next, successively passing both hemispheres over a period of two years.
The monitoring data will be processed and stored onboard 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 the calculation of a unique orbit for the spacecraft.
The device will be launched into a high elliptical orbit around the Earth - it will go around the Earth twice in the time until the Moon completes a circle. This type of orbit is the most stable. There is no space debris and strong radiation that can 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 temporary possibilities of the launch: it must be synchronized with the orbit of the moon. The ship has a small "window" - from March to June - if this period is missed, the mission will not be able to complete the planned tasks.
- According to NASA's published budget, maintaining the exoplanetary telescope in 2018 will cost the agency nearly $27.5 million, out of a total project cost of $321 million.
- The spacecraft will rotate in an orbit that has never been used before. The elliptical orbit, called P/2, is exactly half of the moon's orbital period. This means that TESS will make a complete revolution around the Earth every 13.7 days.
- For the right to launch a satellite, Elon Musk's aerospace corporation withstood serious competition with Boeng. Statistics and NASA were on the side
- The development of instruments - from onboard telescopes to optical receivers - was funded by Google.
TESS is expected to discover thousands of exoplanet candidates. This will help astronomers better understand the structure of planetary systems and provide insight into how our solar system formed.
It's 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, others - in the X-ray. This is the reason for the creation of ever more advanced space systems for deep learning.
Hubble Space Telescope
Telescope "Kepler" (Kepler)
The Kepler telescope was launched by NASA on March 6, 2009. Its special purpose is the search for exoplanets. The telescope's task is to observe the brightness of more than 100 thousand stars for 3.5 years, during which it must determine the number of planets, similar to those located at a distance suitable for life from their suns. Compile a detailed description of these planets and the forms of their orbits, study the properties of stars with planetary systems, and much more. To date, Kepler has identified five star systems and hundreds of new planets, 140 of which are similar in their characteristics to
- Translation
Examples of telescopes (operational as of February 2013) operating at wavelengths across the entire electromagnetic spectrum. Observatories are located above or below the part of the spectrum they normally observe.
When the Hubble Space Telescope was launched in 1990, we were going to take a whole truckload of measurements with it. We were going to see individual stars in distant galaxies that we had not seen before; to measure the deep Universe in a way that was not possible before; peer into star formation regions and see nebulae in unprecedented resolution; catch eruptions on the moons of Jupiter and Saturn in more detail than ever before. But the biggest discoveries—dark energy, supermassive black holes, exoplanets, protoplanetary disks—were unforeseen. Will this trend continue with the James Webb and WFIRST telescopes? Our reader asks:
Without fantasizing about some radical new physics, what results from Webb and WFIRST will surprise you the most?
To make such a prediction, we need to know what measurements these telescopes are capable of.
The completed and launched James Webb Telescope as seen by an artist. Pay attention to the five-layer protection of the telescope from the heat of the sun
James Webb is a new generation space telescope to be launched in October 2018 transl.]. Once fully commissioned and cooled, it will become the most powerful observatory in human history. Its diameter will be 6.5 m, the luminosity will exceed the Hubble one by seven times, and the resolution will be almost three times. It will cover wavelengths from 550 to 30,000 nm - from visible light to infrared. It will be able to measure the colors and spectra of all observable objects, bringing to the limit the benefit of almost every photon that enters it. Its location in space will allow us to see everything within the spectrum it perceives, and not just those waves for which the atmosphere is partially transparent.
The concept of the WFIRST satellite, scheduled for launch in 2024. It will have to provide us with the most accurate measurements of dark energy and other incredible cosmic discoveries.
WFIRST is NASA's flagship mission for the 2020s and is currently set to launch in 2024. The telescope will not be large, infrared, will not cover anything other than what Hubble cannot do. He will just do it better and faster. How much better? Hubble, studying a certain area of the sky, collects light from the entire field of view, and is able to photograph nebulae, planetary systems, galaxies, galaxy clusters, simply by collecting many images and stitching them together. WFIRST will do the same but with a 100x larger field of view. In other words, everything that Hubble can do, WFIRST can do 100 times faster. If we take the same observations that were made during the Hubble eXtreme Deep Field experiment, when Hubble observed the same part of the sky for 23 days and found 5500 galaxies there, then WFIRST would find more than half a million during this time.
Image from the Hubble eXtreme Deep Field experiment, our deepest observation of the universe to date
But we are most interested not in those things known to us, which we will discover with the help of these two beautiful observatories, but in those things about which we still know nothing! The main thing that is needed to expect these discoveries is a good imagination, an idea of what we can still find, and an understanding of the technical sensitivity of these telescopes. In order for the Universe to revolutionize our thinking, it is not at all necessary that the information we have discovered is radically different from what we know. And here are seven candidates for what James Webb and WFIRST can discover!
Size comparison of newly discovered planets orbiting the dim red star TRAPPIST-1 with the Galilean moons of Jupiter and the inner solar system. All the planets found around TRAPPIST-1 are similar in size to Earth, but the star only approaches Jupiter in size.
1) Oxygen-rich atmosphere in a potentially habitable, Earth-sized world. A year ago, the search for Earth-sized worlds in the habitable zones of sun-like stars was at its peak. But the discovery of Proxima b, and the seven Earth-sized worlds around TRAPPIST-1, Earth-sized worlds orbiting small red dwarfs, has created a storm of bitter controversy. If these worlds are inhabited, and if they have an atmosphere, then the comparatively large size of the Earth compared to the size of their stars means that during the transit we will be able to measure the content of their atmosphere! The absorbing effect of molecules - carbon dioxide, methane and oxygen - may provide the first indirect evidence of life. James Webb will be able to see it and the results may shock the world!
The Big Rip scenario will play out if we detect an increase in the strength of dark energy over time
2) Evidence of the impermanence of dark energy and the possible onset of the Big Rip. One of the main scientific goals of WFIRST is to observe stars at very large distances in search of Type Ia supernovae. These same events allowed us to discover dark energy, but instead of tens or hundreds, it will collect information about thousands of events located at vast distances. And it will allow us to measure not only the rate of expansion of the Universe, but also the change in this rate over time, with an accuracy ten times greater than today. If dark energy differs from the cosmological constant by at least 1%, we will find it. And if it is only 1% more in modulus than the negative pressure of the cosmological constant, our Universe will end with a Big Rip. This will definitely come as a surprise, but we have only one Universe, and we should listen to what she is ready to announce about herself.
The most distant galaxy known to date, confirmed by Hubble through spectroscopy, is visible to us as it was when the universe was only 407 million years old
3) Stars and galaxies from earlier times than our theories predict. James Webb, with his infrared eyes, will be able to look into the past when the universe was 200-275 million years old - only 2% of its current age. This should include most of the first galaxies and the late formation of the first stars, but we can also find evidence that previous generations of stars and galaxies existed even earlier. If it turns out that way, it will mean that the gravitational growth from the time of the appearance of the cosmic microwave background (380,000 years) until the formation of the first stars went somehow wrong. This will definitely be an interesting challenge!
The core of the galaxy NGC 4261, like the cores of a huge number of galaxies, shows signs of the presence of a supermassive black hole, both in the infrared and in the X-ray ranges
4) Supermassive black holes that appeared before the first galaxies. As far back as the remotest moments of the past that we have been able to measure, before the time when the universe was about a billion years old, galaxies contain supermassive black holes. The standard theory says that these black holes originated from the first generations of stars that merged together and fell into the center of clusters, and then accumulated matter and turned into supermassive black holes. The standard hope is to find confirmation of this scheme and black holes in the early stages of growth, but it will be a surprise if we find them already fully formed in these very early galaxies. James Webb and WFIRST will be able to shed light on these objects, and finding them in any form will be a serious scientific breakthrough!
Planets discovered by Kepler, sorted by size, as of May 2016, when they released the largest sample of new exoplanets. The most common worlds are slightly larger than Earth and slightly smaller than Neptune, but low-mass worlds simply may not be visible to Kepler.
5) Exoplanets of low mass, only 10% of the Earth, may be the most common. This is the specialty of WFIRST: searching for microlensing over large areas of the sky. When a star passes in front of another star, from our point of view, the curvature of space produces a magnifying effect, with a predictable increase and subsequent decrease in brightness. The presence of planets in the system that was in the foreground will change the light signal and allow us to recognize them with improved accuracy, recognizing masses smaller than any other method can do. With WFIRST, we will probe all the planets down to 10% of Earth's mass, a Mars-sized planet. Are Mars-like worlds more common than Earth-like ones? WFIRST can help us figure it out!
An illustration of CR7, the first known galaxy to contain population III stars, the first stars in the universe. James Webb can take a real photo of this and other such galaxies
6) The first stars may turn out to be more massive than those that exist now. By studying the first stars, we already know that they are very different from the current ones: they were almost 100% pure hydrogen and helium, with no other elements. But other elements play an important role in cooling, radiating, and preventing oversized stars early on. The largest star known today is in the Tarantula Nebula, and is 260 times the mass of the Sun. But in the early Universe there could be stars 300, 500 and even 1000 times heavier than the Sun! James Webb should give us the opportunity to find out, and he can tell us something amazing about the earliest stars in the universe.
The outflow of gas in dwarf galaxies occurs during active star formation, due to which ordinary matter flies away, and dark matter remains.
7) Dark matter may not dominate the first galaxies as much as it does today. We will probably finally be able to measure galaxies in the distant parts of the universe and determine if the ratio of ordinary matter to dark matter is changing. With the intensive formation of new stars, ordinary matter flows out of the galaxy, unless the galaxy is very large - which means that in early, dim galaxies, there should be more normal matter in relation to dark matter than in dim galaxies that are not far from us. Such an observation would confirm the current understanding of dark matter and hit the theories of modified gravity; the opposite observation could refute the theory of dark matter. James Webb will be able to handle this, but the accumulated observational statistics of WFIRST will really clarify everything.
An artist's idea of what the universe might look like when the first stars formed
All these are only possibilities, and there are too many such possibilities to list here. The whole point of observing, accumulating data, and doing scientific research is that we don't know how the universe works until we ask the right questions to help us figure it out. James Webb will focus on four major issues: first light and reionization, galaxy gathering and growth, star birth and planet formation, and the search for planets and the origin of life. WFIRST will focus on dark energy, supernovae, baryon acoustic oscillations, exoplanets - both microlensing and direct observation, and observations of large areas of the sky in the near infrared, which will far exceed the capabilities of previous observatories such as 2MASS and WISE.
All-sky infrared map taken by the WISE spacecraft. WFIRST will greatly exceed the spatial resolution and depth of field available for WISE, allowing us to look deeper and further.
We have an amazingly good understanding of today's universe, but the questions that James Webb and WFIRST will get answered are only being asked today, based on what we have already learned. It may turn out that there will be no surprises on all these fronts, but it is more likely that not only will we find surprises, but that our guesses about their nature will turn out to be completely wrong. Part of the scientific interest is that you never know when or how the universe will surprise you with something new. And when she does, the greatest opportunity of all advanced humanity arrives: she allows us to learn something completely new, and changes the way we understand our physical reality.
Where can you see the stars?
Quite a reasonable question - why place telescopes in space?. Everything is very simple - you can see better from space. To date, to study the Universe, telescopes with a resolution that cannot be obtained on Earth are needed. That is why telescopes are launched into space.
Different types of vision
All these devices have different "vision". Some types of telescopes study space objects in the infrared and ultraviolet range, others - in the X-ray. This is the reason for the creation of more and more perfect space systems for deep study of the Universe.
Hubble Space Telescope
Hubble Space Telescope (HST)
The Hubble telescope is an entire space observatory in low Earth orbit. NASA and the European Space Agency worked on its creation. The telescope was launched into orbit in 1990 and today is the largest optical device that observes in the near infrared and ultraviolet range.
During its work in orbit, Hubble sent to Earth more than 700 thousand images of 22 thousand different celestial objects - planets, stars, galaxies, nebulae. Thousands of astronomers used it to observe the processes taking place in the Universe. So, with the help of Hubble, a lot of protoplanetary formations around stars were discovered, unique pictures of such phenomena as auroras on Jupiter, Saturn and other planets were obtained, and a lot of other invaluable information.
Chandra X-ray Observatory
Chandra X-ray Observatory
The Chandra Space Telescope was launched into space on July 23, 1999. Its main task is to observe X-rays coming from very high-energy cosmic regions. Such studies are of great importance for understanding the evolution of the universe, as well as studying the nature of dark energy - one of the biggest mysteries of modern science. To date, dozens of devices have been launched into space that conduct research in the X-ray range, but, nevertheless, Chandra remains the most powerful and effective in this area.
Spitzer The Spitzer Space Telescope was launched by NASA on August 25, 2003. Its task is to observe the Cosmos in the infrared range, in which one can see cooling stars, giant molecular clouds. The Earth's atmosphere absorbs infrared radiation, in connection with this, such space objects are almost impossible to observe from Earth.
Kepler The Kepler telescope was launched by NASA on March 6, 2009. Its special purpose is the search for exoplanets. The telescope's task is to monitor the brightness of more than 100,000 stars for 3.5 years, during which it must determine the number of Earth-like planets that are at a distance suitable for life from their suns. Compile a detailed description of these planets and the forms of their orbits, study the properties of stars with planetary systems, and much more. To date, Kepler has identified five star systems and hundreds of new planets, 140 of which are Earth-like in characteristics.
James Webb Space Telescope
James Webb Space Telescope (JWST)
It is assumed that when the Hubble has served its term, the JWST space telescope will take its place. It will be equipped with a huge mirror with a diameter of 6.5 m. Its purpose is to detect the first stars and galaxies that appeared as a result of the Big Bang.
And it's even hard to imagine what he will see in space and how it will affect our lives.
How were telescopes invented?
The first telescope appeared at the beginning of the 17th century: several inventors simultaneously invented spyglasses. 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 the rays of light into focus, and an enlarged image is obtained, which can be viewed through the eyepiece located at the other end of the tube. An important date for telescopes is January 7, 1610; then the Italian Galileo Galilei first pointed a telescope into the sky - and that is how he turned it into a telescope. Galileo's telescope was quite small, just over a meter long, and the lens diameter was 53 mm. Since then, telescopes have steadily grown in size. Truly large telescopes located in observatories began to be built in the 20th century. The largest optical telescope today is the Grand 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 are 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 much the same way as a very keen 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 radiations. Looking at space only through it is even worse than seeing the world around in black and white; so we lose a lot of information. Therefore, there are telescopes that work on other 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, which are well suited for detecting new planets outside the solar system: in the visible light of bright stars it is impossible to see the tiny planets orbiting them, but in ultraviolet and infrared light this is much easier to do.
Why do we need telescopes at all?
Good question! Should have asked it earlier. We send vehicles 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 not accessible 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 understanding of 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 be detected using the LIGO observatory, which consists of two observatories that are 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 - to 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 a planet's atmosphere works like a lens: it bends light from celestial objects in a random, unpredictable way - and distorts the way we see them. In addition, the atmosphere absorbs many types of radiation, such as infrared and ultraviolet waves. To get around this interference, telescopes are sent into space. True, this is very expensive, which is why it 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, due to launch in 2018, will be something of a successor to it.
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 all the time; part of this money is for repairs, because the Hubble had to be repaired regularly (this was discontinued in 2009, but the telescope is still in operation). Shortly after the launch of the telescope, a stupid story happened: the first images taken by it were of much worse quality than expected. It turned out that due to a tiny calculation error, the Hubble mirror was not straight 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 is subject to change and will most likely rise closer to launch, but so far it's about $8 billion - and it's worth every cent.
What's so special
at 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 approaching its final stage. The telescope will fly away 1.5 million km from the Earth and enter into orbit around the Sun, or rather, to the second Lagrange point from the Sun and the Earth - this is a place where the gravitational forces of two objects are balanced, and therefore the third object (in this case, a telescope) may remain motionless. The James Webb 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 it will happen.
After that, he will be able to look further than any telescope in history: 13 billion light-years from Earth. Because 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 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 formed, how 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: during the mission, a lot of things can go wrong, and since the telescope will be very far from the Earth, it will be impossible to send it to fix it, as was the case with Hubble.
What is the practical meaning of all this?
This is a question often asked of astronomy, 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 mankind 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. Let's say if astronomers prove the existence of dark matter, it will greatly affect physics. In addition, many of the technologies that were invented for space and astronomy are also used in everyday life: you can think of satellites, which 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 .
