The ‘Boomerang’ (Balloon Observations Of Millimetric Extragalactic Radiation ANd Geomagnetics) project, whose results appear in ‘Nature’ tomorrow [27 April 2000], will provide "exciting high quality data" for cosmology, says ESA astronomer Jan Tauber, project scientist of ESA’s next mission to study the origin and evolution of the Universe, Planck.
 
"The Boomerang experiment is yielding exciting high quality data whose analysis will significantly constrain a few of the dozen or so fundamental cosmological parameters which together describe the global properties of the Universe, such as its total energy density", Tauber thinks.
 
Boomerang has observed the Cosmic Microwave Background (CMB), a
radiation that fills the entire Universe today and that is the first ‘light’ released after the Big Bang. This ‘first light’ — sometimes called the ‘shockwave’ of the Big Bang itself– carries a wealth of information both about the infancy and the final fate of the Universe, information that ESA’s Planck satellite will help to unveil.
 
Boomerang consisted of a telescope suspended from a balloon that circumnavigated the Antarctic for 10 1/2 days during December 1998 and January 1999. Its results build up on those obtained by NASA’s COBE satellite in 1992, which first detected in the CMB the very slight changes in temperature that are associated with the ‘seeds’ of the large structures we see in todays’ Universe (e.g. the large galaxy clusters).
 
Boomerang, funded by agencies from Italy, the U.S. and the U.K., observed these temperature variations in greater detail than COBE, and is hence considered a ‘second generation’ instrument.
 
ESA’s Planck, due for launch in 2007, will launch the ‘third generation’ of instruments to study the CMB. Its goal — much more ambitious than Boomerang’s — is to discriminate between models describing the origin and evolution of the Universe by measuring the key parameters that constrain them — such as the rate of expansion of the Universe or the nature and density of the so-called dark matter, for instance. Planck’s sensitivity and resolution will guarantee a very high degree of confidence in these measurements.
 
"Planck will allow to constrain most parameters simultaneously and thus provide true discriminatory ability between many different Universes still in agreement with experiments such as Boomerang", Tauber says.
 
Planck satellite will be built starting in 2001. It will carry two sets of detectors covering the 30-857 Gigahertz (GHz) waveband, corresponding to a range from microwaves to the far-infrared. They are now being built by more than 40 institutes, most of them European (and a few from the U.S.).
 
Jan Tauber, Planck project scientist
Tel +31 71 565-5342
jtauber@astro.estec.esa.nl
 
USEFUL LINKS FOR THIS STORY
 
* More about Planck
  http://sci.esa.int/planck
* Boomerang article (Nature)
  http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v404/n6781/full/404955a0_fs.html
 
IMAGE CAPTION:
[http://sci.esa.int/content/image/index.cfm?aid=17&cid=40&oid=18245&objecttypename=news&ooid=18230]