Sometimes when people talk about astronomy, they ask “What is the best telescope ever made?” or “Which telescope is the best right now?”. Really questions like these are some of the hardest ones to answer. Almost like asking “What the most amazing object in the cosmos?” these questions are hard to answer because they can be entirely objective and depend on who is answering the question.
There are a lot of telescopes that I would define as the best telescopes, though I might feel that way about them, other scientists might not. For example, I like many people have a special place in our hearts for the Hubble Space Telescope. I saw this telescope launch into space just shortly after I was born, and have been enjoying the celestial views this orbiting telescope has been bringing us ever since. I could bring up countless examples of things I love about the Hubble, I think my favorite being the Hubble Ultra Deep Field, which is an image that was able to be captured thanks to Hubble’s incredible ability to observe the same patch of sky for 11 straight days. This patch of sky, to any other telescope is just a blank patch of night. After 11 days of the Hubble Telescope imaging this one piece of sky, the black patch ended up having thousands upon thousands of galaxies filling the picture. It was incredible to see things that were previously too dark and distant to see.
But like I said, this is one persons opinion. My fiance on the other hand has a different opinion. While she still fancies the orbital telescopes, she is more interest in the Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer(WISE) which is another NASA satellite that was designed to find as many asteroids, especially near Earth asteroids, as possible. Of course this is an entirely different telescope than the Hubble Space Telescope, but WISE is still an incredible mission. My fiance has a special interest in this mission because she is interested in asteroids and the danger they can pose to society. This example right here is why it is difficult to define the best telescope.
There are so many different types of telescopes, optical, infrared, radio, x-ray, gamma-ray.. The list is always growing because they are constantly working on new ways to observe the universe. Scientists are working to stretch our understanding of the cosmos so that we can use telescopes to detect things like dark energy and dark matter. They are building underground telescopes to detect particles like neutrinos. Depending on the type of scientist you are, and what you are interested in learning about you will generally have different opinions on what you consider the best telescope available. Of course for the general public it is easier for them to pick their favorite. Most people would usually pick the Hubble Space Telescope, one of the best know telescopes ever. But when the general public asks a scientist, they never quite know which observatory will be their first pick in the bunch.