Astronomers look forward to Herschel's views of the distant universe

Professor Matt Griffin of the School of Physics and Astronomy at Cardiff University will describe the prospects for observations of distant galaxies in his talk on Monday 9 July at the ‘From IRAS to Herschel and Planck’ conference at the Geological Society in London. The meeting is being held to celebrate the 65th birthday of Royal Astronomical Society President Professor Michael Rowan-Robinson, who has been a leading figure in infrared astronomy for the last three decades.

Herschel is named after the British astronomer William Herschel, who made the first detection infrared radiation in 1800, some 19 years after he discovered the planet Uranus. It will be the largest astronomical telescope yet flown in space, with a diameter of 3.5 metres, and will carry three sophisticated scientific instruments – SPIRE (the Spectral and Photometric Imaging Receiver), HIFI (the Heterodyne Instrument for the Far Infrared) and PACS (Photodetector Array Camera and Spectrometer). These are designed to view the Universe in the far infrared and sub-millimetre wavelength bands that cannot be seen from the ground because this radiation cannot penetrate the Earth's atmosphere to reach the ground.

Large galaxies like our own are thought to have formed in the past by the merging of smaller galaxies. These mergers usually caused intense episodes of star formation in the new galaxy, the signs of which can best be observed in the far infrared part of the spectrum. This is because star formation occurs deep inside clouds of gas and dust from which no visible light can emerge – but far infrared light can get out, carrying with it the signatures of what's going on inside. When astronomers observe very distant objects, they see them as they were a long time ago, so by observing galaxies at very large distances, Herschel will show us how they formed as a result of these cosmic collisions.

Closer to home, Herschel's instruments will be used to study in great detail how stars and planetary systems continue to form in our own galaxy today, and to investigate the planets, comets and satellites of our own Solar System.