How we're building the world's biggest optical telescope to crack some of the greatest puzzles in science
Now a large group of astronomers from all over the world is building the biggest optical telescope ever – the Extremely Large Telescope (ELT) — in Chile.
- Now a large group of astronomers from all over the world is building the biggest optical telescope ever – the Extremely Large Telescope (ELT) — in Chile.
- Once construction is completed in 2028, it could provide answers that transform our knowledge of the universe.
- With its 39-metre diameter primary mirror, the ELT will contain the largest, most perfect reflecting surface ever made.
Alien life
- The ELT may also offer an answer to the most fundamental question of all: are we alone in the universe?
- Occupying the so-called Goldilocks zone, these Earth-like planets will orbit their star at just the right distance for water to neither boil nor freeze – providing the conditions for life to exist.
- To learn if life is likely to exist on an exoplanet, astronomers must complement imaging with spectroscopy.
- While images reveal shape, size and structure, spectra tell us about the speed, temperature and even the chemistry of astronomical objects.
- For giant exoplanets, the Harmoni instrument will analyse light that has travelled through their atmospheres, looking for the signs of water, oxygen, methane, carbon dioxide and other gases that indicate the existence of life.
- From previous satellite missions, astronomers already have a good idea of where to look in the sky for exoplanets.
- Tiny shifts in the positions of these features — around 1/10,000th of a pixel on the Andes sensor — may, over months and years, reveal the periodic wobbles.
- This scale will remain constant over decades, mitigating the measurement errors that occur from environmental changes in temperature and pressure.
- It is only by looking far outside our Solar System that we can gain a perspective beyond the here and now.
Derryck Reid receives funding from the UK Science and Technology Facilities Council (STFC).