The first instrument for the James Webb Space Telescope (JWST) was completed and handed over to NASA, according to the Max Planck Institute for Astronomy (MPIA). The mid-infrared instrument (MIRI), a pioneering camera and spectrograph, is so sensitive that it could see a candle on one of Jupiter’s moons. Key components of the new instrument were designed and built at MPIA. The successor to the Hubble Space Telescope, JWST will explore the era of the first stars, trace the assembly of early galaxies, and examine in detail the birth of stars and planetary systems as well as the characteristics of planets around distant stars. To achieve such an ambitious goal, JWST will rely not only on its 6.5-m mirror but also on a suite of four sensitive instruments. MIRI, which was handed over to NASA last week in a ceremony at the Institute of Engineering and Technology in London, was the first of these to be completed. The filter wheel of the MIRI instrument can position various kinds of filters and masks in front of the detector with high precision, enabling the instrument to take various kinds of images and spectra. (Image: MPIA) “MIRI is sensitive to a particular range of infrared radiation (at wavelengths of 5 to 28 µm) that will allow us to peer inside the clouds where stars and planets are born — and witness such cosmic births in unprecedented detail,” said Thomas Henning, director of MPIA and a leader of the European consortium that built the instrument. “We will be able to examine in detail the swirling disks of gas and dust in which planets are forming.” At the same wavelengths, MIRI also will be able to detect star formation in very early galaxies and help other JWST instruments to identify the first stars in the universe. Building MIRI presented numerous technological challenges. “MIRI is a very versatile instrument — you can insert a number of different filters and other elements that allow MIRI to perform different kinds of measurements, such as taking images and spectra,” said Oliver Krause, head of MPIA’s Infrared Space Astronomy group. “But when it comes to space telescopes, even something as simple as positioning a filter very precisely in front of a detector is a major challenge.” Krause’s group solved that challenge by providing the mechanics for the filter wheel. MPIA was also involved in the instrument’s electrical system and testing. MIRI will now be transported to NASA’s Goddard Space Flight Center in Maryland. Once it arrives, it will be integrated with the other instruments and undergo two years of testing to ensure that they all function correctly together. It will then be integrated and tested with the telescope optics. JWST is scheduled to launch in 2018. For more information, visit: www.mpia.de