CMB Mapping: Asking the Universe for an ID

Believe it or not, there is a way to ask the Universe for an ID. The Planck satellite, launched jointly by the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA), has as its main mission the mapping of the cosmic microwave background (CMB), which many scientists claim to be the remnant radiation of the Big Bang event that created our universe. Specifically, the satellite will measure temperature and polarization fluctuations with resolution and sensitivity unmatched by any technology previously (Yarris, 2005).

The satellite is not the first of its kind to be launched. NASA's Cosmic Background Explorer (COBE) satellite has been in orbit and operational since 1989, although its instruments are not nearly as sensitive as those that the Planck satellite is carrying (Yarris, 2005). Another, more recent addition to studying CMB is the Microwave Anisotropy Probe (MAP), also known as Wilkinson Microwave Anisotropy Probe (WMAP), launched in 2001 (Richmond, 2008). Some observations and studies also have been conducted from the Earth's surface, all of them aimed at finding out more about the nature of the universe's birth, the formation of the galaxies, and other cosmic events based on fluctuations in temperature and polarization in the captured CMB radiation.

All of these experiments are based on the commonly accepted cosmological model of the universe's creation - specifically the Big Bang, which has been estimated to occur somewhat less than 15 billion years ago (Yarris, 2005). What the satellite equipment is capturing are photons that have been actively moving throughout the entire universe shortly (in cosmological terms) after the universe's rapid expansion and cooling. By now, these photons have cooled to a very low temperature - below 3 Kelvin - but still emit radiation in wavelength of about 1 millimeter (NASA, 2008). Scientists hypothesize that temperature fluctuations among these photons is the force responsible for the creation of individual cosmic bodies and the galaxies that they comprise. Among other things, data gathered from CMB is expected to clarify some issues around the Hubble constant, the cosmological constant, and increase human understanding of the process of universe's expansion (Richmond, 2008).

One of the challenges presented by the satellite's capability to gather enormous amounts of data was processing it. The problem was seemingly resolved in 2005, when a group of researchers at Berkeley Lab used a Department of Energy's supercomputer to process a year's worth of simulated Planck satellite's data and create a comprehensive map within a single most CMB-sensitive frequency in under two hours (Yarris, 2005).

References

NASA. (2006). Universe 101: Our universe. NASA Website (October 14). Online at http://map.gsfc.nasa.gov/universe/bb_cosmo_fluct.html

Richmond, M. (2008). The microwave background. Rochester Institute of Technology. Online at http://spiff.rit.edu/classes/phys240/lectures/cmb/cmb.html

Yarris, L. (2005). Simulating a map of the cosmic microwave background: What the Planck satellite will see. Berkeley Lab (February 18). Online at http://newscenter.lbl.gov/feature-stories/2005/02/18/simulating-a-map-of-the-cosmic-microwave-background-what-the-planck-satellite-will-see/