Free Astronomy Magazine January-February 2016

SPACE CHRONICLES signals from water and other mole- cules within the Milky Way, other nearby galaxies and the early Uni- verse. Installed on APEX earlier this year, SEPIA is sensitive to light with wavelengths in the range 1.4–1.9 millimetres (frequencies between 158 and 211 GHz). The exceptional observing condi- tions on the extremely dry Chajnan- tor Plateau in northern Chile mean that, although this light is blocked First observations from SEPIA by ESO A new instrument attached to the 12-metre Atacama Path- finder Experiment (APEX) telescope at 5000 metres above sea level in the Chilean Andes is open- ing up a previously unexplored window on the Universe. The Swedish–ESO PI receiver for APEX (SEPIA) will detect the faint T his picture shows the SEPIA in- strument after installation. [ESO/Carlos Duran] A new instrument attached to the 12-metre Atacama Pathfinder Experi- ment (APEX) telescope at 5000 metres above sea level in the Chilean Andes is opening up a previously unexplored window on the Universe. The Swedish–ESO PI receiver for APEX (SEPIA) will detect the faint signals from water and other molecules within the Milky Way, other nearby galaxies and the early Universe. In this picture engineers from Onsala Space Observatory's Group for Advanced Receiver Development examine the top part of SEPIA before installation at APEX. On the left, Mathias Fredrixon and Denis Mele- din (leaning down), and behind them Igor Lapkin. [ESO/Sascha Krause] by water vapour in the atmosphere at most places on Earth, SEPIA is still able to detect the faint signals coming from space. This wavelength region is of great interest to astronomers as signals from water in space are found here. Water is an important indicator of many astrophysical processes, in- cluding the formation of stars, and is believed to play an important role in the origin of life. Studying water in space — in molecular clouds, in star-forming regions and even in comets within the Solar System — is expected to provide critical clues to the role of water in the Milky Way and in the history of the Earth. In addition, SEPIA’s sensitivity makes it