The PLANCK satellite |
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The PLANCK satellite
The Planck satellite, built to map the anisotropies of the cosmic background micro-wave radiation of the Universe with unprecedented accuracy (it will be 30 times as sensitive as WMAP and 1.000 times as COBE) will be launched in summer 2008 by Ariane together with the infrared space telescope Herschel. Being assembled by Alcatel Alenia Space in Cannes, this satellite from the European Space Agency was presented to the media on February the 1st. Planck will have on board two microwave instruments LFI at low frequency and HFI at higher frequency. The latter was made in a large part by french laboratories with the support from CNES, and its instrument scientist is J-M. Lamarre, director of LERMA at Paris Observatory.
Nearly 60 journalists have visited the Alcatel Alenia Space factory in Cannes to see the Planck satellite near the end of its integration. Planck will map the whole sky in 9 bands from 0.3 to 10mm in wavelength. 30 times as sensitive as its predecessor WMAP and 1000 times as COBE, Planck is the third generation of satellites dedicated to the cosmic microwave background. It will also provide the scientific community accurate maps in a wavelength domain very little explored. Numerous sectors of astrophysics will benefit from these data.
Figure 1: Artist's view of the satellite PLANCK. Planck will be launched on an Ariane-5 from the Guiana Space Centre, Kourou, French Guiana, at the end of July 2008. It will be launched together with ESA's Herschel spacecraft, in a dual launch configuration. About 2.5 hours after launch, Planck separates from Herschel, and then starts its cruise to L2 (second Lagrangian point in space), its destination, where it will arrive in less than 6 months.
Credit ESA
Click on the image to enlarge itThe main objective of Planck remains the study of the anisotropies in the emission of the universe at age of 300000 yrs. Their spatial frequency distribution represents both a spectacular confirmation of modern cosmology theories and a precious indicator of the physics of the early universe. The discovery of these anisotropies by the COBE satellite was recently awarded the Nobel prize in physics (see in Fig 2 the photo of George Smoot in front of Planck telescope).
Figure 2: George F.Smoot, Nobel Prize for Physics in 2006, views the Planck satellite in the Alcatel Alenia Space facilities in Cannes, France, on 1 February 2007. Smoot, from the Lawrence Berkeley National Lab., Univ of California, shares the Nobel prize with John C. Mather (NASA) for the discovery of the blackbody form and anisotropy of the Cosmic Background Radiation - Planck's object of study. The telescope has an effective diameter of 1.5m and will be cooled passively down to about 40 Kelvin. The Planck satellite can be seen in the background. It can be contained in a volume of 64 cubic meter.
Credit ESA, S. Corvaja
Click on the image to enlarge it
The HFI instrument, based on bolometres cooled down to 0.1Kelvin, was designed by an international consortium in which the first rôle was played by french laboratories in astrophysics and physics: IAS, IAP, LERMA, LAOG, LAL, APC, CESR, CRTBT and LPSC joined their efforts to produce an instrument with sensitivity only limited by quantum fluctuations of the observed flux itself. In this domain, HFI has twice better performances than was specified 10 years ago.
Press Release de l'ESA
Planck satellite shows its beauty
Reference
J.-M. Lamarre et al. 2003, "The Planck High Frequency Instrument, a third generation CMB experiment and a full-sky submm survey", New Astronomy Reviews, Volume 47, Issue 11-12, p. 1017-1024
Contact
Jean-Michel Lamarre (Observatoire de Paris, LERMA et CNRS )
