UK ELT Programme PPRP 2022

The Extremely Large Telescope (ELT) is now under construction in the Atacama Desert in northern Chile by the European Southern Observatory (ESO). With a diameter of 39m and a greater collecting area than all current large telescopes combined, the sensitivity and spatial resolution of the ELT will dwarf those of existing facilities in the visible and infrared. With the first observations planned for 2027, the sheer sensitivity of the ELT is truly remarkable, with a collecting area over 18 times that of ESO's current largest telescopes. The telescope will also continuously correct the light from astronomical objects with a technique called adaptive optics, giving astronomers images with five times better resolution than possible today.

This vast step forward in both collecting area and image resolution from the ELT will be transformative for nearly every aspect of contemporary astronomy, from searches for molecules potentially linked to life in nearby exoplanets, out to detection of the most distant galaxies at the edge of the observable Universe. It will give us our first detailed views of individual stars in galaxies which are millions of light-years beyond the Milky Way and help to settle arguments as to whether some of the fundamental constants of physics vary in space and time. It will have the capabilities to directly detect mature planets similar to those in our Solar System around nearby stars, while also probing the distribution of elusive dark matter in galaxies when the Universe was just 10% of its current age. This is just a small subset of the diverse and profound scientific breakthroughs we expect from the ELT, and UK astronomers and engineers are playing leading roles in the development of the cameras and spectrographs that will take the valuable observations in the late 2020s and beyond.

Building on more than 15 years of scientific and technical development, the UK ELT Programme coordinates the UK roles in ELT instrumentation. At the core of the programme is leadership of the design and construction of the HARMONI instrument, one of the two first-light instruments for the telescope, ensuring UK astronomers will be well prepared to reap the rewards from ELT observations as soon as possible and some of its first discoveries.

The programme also includes smaller roles in future instruments, so that UK astronomers can exploit as much as possible of the tremendous new discovery space of the ELT. The UK is building the high-resolution spectrograph for METIS, the third instrument for the ELT, now in construction (led by the Netherlands). UK groups also have key roles in soon-to-commence construction of the next instruments, ANDES (formerly HIRES, led by Italy) and MOSAIC (led by France), both of which will be essential to exploit the huge scientific opportunities of the observatory. Lastly, the programme is investing in research and development of new technologies that will influence the design of future ELT instruments, particularly the development of the PCS instrument for studies of exoplanets.