A group of astronomers has found that NASA’s idea of a telescope, shelved by NASA a decade ago, will solve a problem that no other telescope can handle: it can study the first stars in the universe. Scientists will publish their findings in the next issue of the Astrophysical Journal, but for now the article is available on the preprint service.
Throughout the history of astronomy, telescopes have become more powerful. The next James Webb Space Telescope will provide a glimpse into the time when the first galaxies were forming. However, the Big Bang theory predicts that there was an even earlier time. Then galaxies did not exist yet, but the first stars were formed – the hypothetical stellar population III. Even Webb will not be able to study this “very first light”. We need another, “perfect” telescope.
Professor Volker Bromm, one of the study authors
These first stars formed about 13 billion years ago. They are unique, born from a mixture of hydrogen and helium gases and are probably tens or 100 times larger than the Sun.
New calculations by scientists have proven that a previously proposed installation, a liquid mirror telescope on the lunar surface, is capable of studying these stars. Proposed in 2008 by a group led by Roger Angel of the University of Arizona, this object has been named the Liquid Mirror Lunar Telescope (LLMT).
NASA reviewed the project but decided not to pursue it.
The proposed lunar telescope has a mirror diameter of 100 meters. It will operate autonomously from the lunar surface, powered by solar energy and transmitting data to a satellite in lunar orbit.
The telescope’s mirror will not be made of coated glass, but liquid, as it is lighter and therefore cheaper to transport to the moon. The telescope mirror would be a rotating vat of liquid topped with a metallic – and therefore reflective – liquid. (Previous liquid mirror telescopes used mercury.) The chan must rotate continuously for the liquid surface to have the correct paraboloid shape and act like a mirror.
The telescope will be stationary and located inside a crater at the north or south pole of the moon. To study the first stars, he will constantly look at the same section of the sky in order to collect as much light as possible from them.
The team hopes the astronomical community will revisit a pending plan for a liquid-mirror lunar telescope to study the very first stars in the universe and events just after the Big Bang.