Looking into the dark: Ahead with the Euclid mission
On 19. June, the European Space Agency (ESA) formally adopted the largest collaboration of astronomers in the World, including scientists at the Max Planck Institute for Extraterrestrial Physics to help build the Euclid satellite. Euclid will study the ``Dark Universe” with great precision, tracing the distribution and evolution of the enigmatic dark matter and dark energy throughout the Universe.
“This is it”, says Yannick Mellier from the Institut d'Astrophysique de Paris (IAP), and the lead of the Euclid Consortium (EC) selected today by ESA, “ESA and the Euclid Consortium have worked for over 5 years to get to this point and now we are formally adopted to help build this exciting new space mission.” ESA today also endorsed a Multilateral Agreement (MLA) between thirteen European space agencies, NASA, and the Euclid Consortium, for the construction of key elements of the Euclid satellite, specifically the onboard instruments, software for analysing the data and the satellites scientific leadership.
“We have put together a fantastic team”, continues Mellier, “with nearly 1000 scientists involved in our collaboration from across Europe and other parts of the World. We have experts in all aspects of astronomy, physics, satellite and software design.” The Euclid Consortium will provide two instruments to ESA, a visible imaging instrument, VIS, and a near infrared imaging and spectrograph instrument, NISP. These state-of-the-art instruments, equipped with wide field cameras, will create a huge amount of exceptional quality data over a large fraction of the sky.
Scientists at the MPE are responsible for the overall optical design of the near-infrared instrument; the institute will procure all lenses and their mounts and perform the corresponding functionality tests. The Ludwig Maximilians-University (LMU) is co-leading the preparation of ground-based complementary data and their merging with the Euclid visual and infrared data. Both institutes are represented in several science working groups, in the Euclid Consortium Board and the ESA Science Team. Moreover, the Max Planck Institute for Astronomy (MPIA) in Heidelberg will develop and manufacture the broad band filters as well as setting up the scientific data centre; the Argelander Institute for Astronomy (AIfA) at the Rheinische Friedrich-Wilhelms-Universität Bonn will contribute to the software development and the scientific data centre.
“Euclid will provide a wealth of data on the three dimensional matter distribution in the universe”, explains Ralf Bender from MPE, the German representative in the Euclid Board. “Not only will this give us interesting insights into the evolution of galaxies and galaxy clusters, we will also be able to better understand the accelerating expansion of the universe. Hopefully, this will bring us a big step forward in solving the riddle that is Dark Energy.”
Euclid will use a 1.2-m diameter telescope and the two instruments to map the three-dimensional distribution of some two billion galaxies and of the dark matter that surrounds them, over one third of the whole sky. Stretched across ten billion light years of the Universe, the results of the mission will plot the evolution of structure over three-quarters of its history.
Euclid is now an official ESA mission and solidifies the Euclid Consortium at forefront of worldwide research into the “Dark Universe”. German contributions to the Euclid mission are supported substantially by the DLR space administration with funds provided by the Federal Ministry of Economics and Technology.
Euclid is an M-class mission and is part of the ESA Cosmic Vision programme 2015-2025. Euclid is a 1.2m space telescope, located at 2nd large Sun-Earth Lagrange point, and will perform two major surveys of the sky over at least 5 years. The wide survey will cover 40% of the whole sky and is focused on mapping the locations and shapes of billions of galaxies. The Euclid deep field will cover a patch of the sky approximately 100 times the size of the full Moon (or 15,000 times larger than the Hubble Ultra Deep Field), to unprecedented depths. The combination of depth and sky coverage will enable Euclid to detect very rare sources like extremely high redshift quasars, and maybe the first galaxies that ever formed.
Euclid was formally selected in October 2011 for flight, with the Euclid Consortium adopted to help build Euclid on June 20th 2012. ESA will provide to the Euclid mission the spacecraft (built by industry under contract), the launch on a Soyuz rocket from the Kourou base in Guyana, operations for at least 6 years, and mission archives. The EC will provide the scientific instruments for Euclid (VIS & NISP), the data processing and scientific analysis software and archiving as well as scientific leadership for the mission. The EC is comprised of nearly a 1000 scientists from hundreds of institutions in Austria, Denmark, Italy, Finland, France, Germany, Netherlands, Norway, Portugal, Romania, Spain, Switzerland and UK, as well as contributions from US laboratories.
For nearly 80 years now, astronomers have known about “dark matter”; matter than does not shine or reflect light and can only be detected through its gravitational influence. Scientists still do not know the true physical nature of dark matter, but its existence has been confirmed numerous times over the last few decades. In 1998, astronomers found evidence for an even stranger component to the dark universe, namely “dark energy” that appears to driving the expansion of the Universe faster and faster. The Nobel prize was awarded for this discovery in 2011. The “dark energy” makes up three quarters of the energy budget of the Universe; three times the energy associated with dark matter and over 15 times the energy in normal matter like atoms. There are many ideas of what it could be, but so far there is no compelling explanation for the nature of this mysterious substance in the Universe. Astrophysicists believe that the discovery of its very nature will revolutionize fundamental physics and our knowledge of the physical laws of nature.