Exoplanets

Exploring the universe

Very Large Telescopes and Extremely Large Telescopes


Just now the in the Atacama desert, on the top of the mountain Cerro Armazones, north Chile. A new generation of land-based optical telescopes is being built. 
It is built by the European Southern Observatory ESO that is a European astronomic organization with several telescopes already located on the southern hemisphere.
In north Chile they already have this generation optical telescopes in operation called Very Large Telescopes VLT. The new generation telescopes will be operational in 2024 and it is called Extremely Large Telescopes ELT. Astronomers imagination is not the best when it comes to the naming of their gadgets, but rest assured that these gadgets will live up to their name.

So how much better will ELT be than VLT? 
Will we be able to make new discoveries about the universe?
Will we be able to find new Earth-like exoplanets with these telescopes?

VLT consist of four large telescopes width a diameter of 8.2 meters. The telescopes are located in a formation. They can work both independently and together. The total mirror surface has a diameter of a 16-meter telescope when they are coordinated. VLT is the largest Telescopes on earth.
Some important discoveries made by VLT telescopes so far has been: 

  • The largest star ever R136A1 about 165000 light years away. It is over twice the size the scientists thought a star could have 
  • For the first time revealed the effects predicted by Einstein's general relativity on the motion of a star passing closed to a black hole.
  • That the young universe was much bluer than it is today and had fewer stars, 
  • First direct image of an exoplanet. A five times Jupiter size planet orbiting a brown dwarf
  • Earth-like planet in our closed star system Proxima Centauri b
  • The discovery of TRAPPIST 1 system 
  • The atmosphere around a super-Earth exoplanet called GJ 1214b, was analyzed mostly gaseous water 

ELT image credit:
ESO/L. Calçada

ELT is an optical reflector telescope. The primary mirror will be 39.3 m in diameter composed of 798 hexagonal segments. The mirror will have a light absorption area of 978 m². Above this huge reflector, there is also a 4.2-meter diameter secondary mirror.

ELT will be much larger than VLT, it will gather 13 times more light. ELT will be able to correct for atmospheric distortions. The telescope will be able to take from earth 16 times sharper images than the Hubble Telescope that is in space.
Consider the impressive resume of VLT and Hubble we will have many existing reports about discoveries when ELT gets fully operational. 
The main task of ELT will be to look for an exoplanet. By measurements of the wobbling movements, stars show because planets orbit around them, but also take direct images of large Jovians. Perhaps it will be possible for the telescope to characterize the atmospheres of the planets, and to take direct images of planets of Earth's size.
 

Read more at ESO