2. Creation revealed

‘Creation revealed’ examines key observations on planetary systems. Astronomers at first could probe the Universe only through the medium of visible light. In the early 1600s, the invention of the telescope allowed the Universe to be observed in much greater detail. With the discovery of ‘heat rays’, the seeds of infrared astronomy were planted. Meanwhile, throughout the course of the nineteenth century, one of the grandest unifications in physics was accomplished. It was discovered that the forces of electricity and magnetism were in fact different aspects of the same phenomenon: electromagnetism. Other important topics include blackbody radiation; infrared observations of young stellar objects; and the Atacama Large Millimeter/Submillimeter Array (ALMA).

Is the Moon the future of infrared astronomy?

Infrared astronomy, particularly in spectroscopy, could benefit in a decisive way from an implementation of telescopes on the Moon since the largest telescopes on Earth are practically limited to 40 m and in space to 10 m. On the Moon, a collector larger than on Earth becomes conceivable, thanks to the low gravity and the absence of wind, in having the advantages of space. Passively cooled in the bottom of a permanently shadowed crater at the northern or the southern pole, it could reach unprecedented spectral sensitivity on a large part of the infrared domain, making possible spectral analysis of the most primitive galaxies and of the terrestrial exoplanet atmospheres. A project aiming at the detection of the weak cosmic microwave background spectral distortions is also presented. Several identical 1.5 m cryo-cooled telescopes at 2.5 K to fit in a launcher, with an imaging Fourier transform spectrometer in each unit, deposited in a cold crater and pointing in the same direction in lunar survey mode, would build for this fundamental goal the equivalent of a large telescope at an extremely low temperature. Last, the feasibility of these projects is discussed. This article is part of a discussion meeting issue ‘Astronomy from the Moon: the next decades'.