At the end of December 2021, the whole world followed the launch of the James Webb Space Telescope, the continuer of the Hubble Telescope, which for three decades of observation obtained the most fantastic photographs and scientific results, more than any other telescope. James Webb, a hundred times more powerful than Hubble, will explore the first stars and galaxies in the primordial universe and look for signs of life on exoplanets in distant solar systems.

In addition to the IKU introductory lecture, an AIS course is offered on the history and scientific achievements of telescopes in space, with an emphasis on Hubble and James Webb, but not only them. In addition to Hubble, which observes mainly in visible light, many telescopes have been sent that work with other types of radiation, such as Spitzer in infrared, Chandra in X-rays, Plank in microwave radiation, Kepler to discover exoplanets and many more, each revolutionized our understanding of the universe. During its 30 years of operation, the Hubble Telescope has achieved amazing images and results, far more than any other telescope, on Earth or in space. We will see the most prominent images of Hubble: from planets and satellites in our solar system to proto-galaxies before in the young universe.

The new James Webb spacecraft (JWST) will observe even further than Hubble, reaching out to the first galaxies that appeared just 300 million years after the Big Bang. Unlike Hubble, which orbits the Earth at an altitude of about 600 km, JWST will orbit the sun 1.5 million km away from Earth. Due to this remote location, JWST will not be accessible by repair missions, as was Hubble, and its hardware, which is much more complex than Hubble’s, must work perfectly. A hundred times more powerful than Hubble, James Webb will be able to make unprecedented observations that have so far been beyond the reach of humanity, such as the appearance of the first stars in the universe and the search for signs of life on exoplanets. Finally, we will try to understand why space agencies like NASA and ESA (the European Space Agency) are investing huge sums of money to send telescopes into space. Telescopes on Earth are limited by the atmosphere, which obscures the image in visible light, to which the atmosphere is apparently transparent. In addition, there are types of radiation such as ultraviolet (UV), X-rays and gamma rays that are blocked by the atmosphere, so to observe them it is necessary to send dedicated telescopes out of the atmosphere. To get a complete picture of the universe, astrophysicists also use these types of radiation with special space telescopes. We will hear about missions like Spitzer and Herschel in the infrared, ROSAT, XTE and Chandra in X-rays, and Compton, INTEGRAL and Fermi in gamma rays.

A separate family of satellite telescopes has investigated the Cosmic Microwave Background, the most convincing proof of the Big Bang theory. For the most part, this radiation does not penetrate through the atmosphere and must therefore be studied by space telescopes such as COBE, WMAX and Plank. Earth-like telescopes are also not capable of detecting exoplanets. For this purpose NASA sent the Kepler spacecraft, which for 5 years discovered thousands of planets, several of which JWST will investigate for signs of life.