The Extremely Large Telescope (yes, that's what it's called), which will be the largest telescope in human history, has been under construction in the Chilean desert for 10 years. Its primary mirror will be about 4 times larger than any of the existing telescopes, allowing it to capture 15 times more light and surpass the orbiting Hubble in detail by 16 times. Construction began back in 2014 and today the telescope is just over 50% complete. It is planned to put it into operation in 2028, and the cost of the project may exceed $1.5 billion