MONSTER SCIENCE
In two feature articles, Govert Schilling looks into the future of optical and near-infrared ground-based astronomy. Last issue’s article described the next generation of extremely large telescopes; this issue’s story focuses on the outstanding science questions they will explore.
“IT’S DIFFICULT TO MAKE PREDICTIONS, especially about the future.” This quote, which has been attributed to Niels Bohr, Mark Twain and Yogi Berra, among others, is particularly true of the development of astronomy. In their exploration of the universe, humans continuously stumble upon unexpected discoveries and insights.
Still, you can’t make progress without some form of preparation. If you design a new generation of extremely large telescopes, you have to think about the scientific riddles you want to solve and about the best way to tackle the accompanying challenges. So what do astronomers hope to learn, and how do they plan to achieve their goals?
Over the past few years, large international working groups for the three monster telescope projects of the 2020s — the Giant Magellan Telescope (GMT), the Thirty Meter Telescope (TMT) and the Extremely Large Telescope (ELT) — have prepared comprehensive inventories of the scientific questions their instruments are expected to address. These so-called science cases, which are freely available for download, comprise 202, 204 and 772 pages for the TMT, GMT, and ELT, respectively. In general, the three future telescopes plan to focus on the same scientific spearheads: cosmology, galaxy evolution, fundamental physics, the origin of stars and planets, exoplanets and Solar System science. Yes, that’s about all of astronomy — the telescope giants of the next decade will be as versatile as the Hubble Space Telescope has been, which of course is a good thing for billion-dollar projects.
But without their suites of instruments and detectors, the megascopes would all be blind: If a huge telescope mirror is the ‘lens’ of a giant eye on the cosmos, the observational instruments constitute
