Planck surveys the entire sky and starts over

The ESA space telescope tasked with observing the Universe just after it came into being has reached an important milestone.

 

Planck: the observatory of the beginning of the Universe (illustration). Credit: ESA

Launched on 14 May 2009 with another space telescope (Herschel), Planck is a rather special type of observatory. First of all, it is (very) sensitive in the realm of microwave wavelengths. Why? Because the first light emitted 300,000 years after the Big-Bang (the birth of our Universe) was shifted so far by the expansion of the Cosmos that it reaches us in the form of microwave wavelengths...

A complete survey of the sky
And obviously “to see” this light, also called “relic radiation”, is to get a better understanding of how this incredible, apparently uniform energy then gave birth to the Universe as we observe it. However, the uniformity is but superficial as, by measuring the differences in temperature (in the region of one millionth of a degree) of this radiation extremely accurately, we can find the “imperfections” around which matter is gradually going to congregate, which will then give rise to the stars and galaxies that we know. This is where the second particularity of Planck comes in: to successfully complete its mission, it is scanning the entire canopy of heaven to provide researchers with an overall portrait of the cosmos as it was just 300,000 years after the Big Bang. The animated video below shows how the observatory turns on itself as it surveys.



On 14 February 2010, this telescope of the beginning of time belonging to the ESA, European Space Agency, finished its first complete scan of the sky and started on its second which will be used for refining measurements. So to be exact, Planck has scanned 95% of the canopy of heaven and the missing 5% is to be collected during the second scan of the sky between now and next June. The video below is another animated film which shows the type of data obtained (reconstituted from the observations of WMAP, Planck’s American predecessor).



Cosmology aboard the ISS
The map obtained in this way might appear most strange with its light blue “lumps” on the dark background... And yet, it is like a treasure map for astronomers. The large white bar is our galaxy seen edge-on. But the rest shows how the Cosmos began organising itself and when the data is analysed, it is going to put heavy restrictions on theoretical models as regards such essential points as inflation (vast expansion of the Universe at the time of the Big Bang), black matter (matter that we cannot see, but whose presence can be measured by its gravitational effects) and black energy (energy that speeds up the expansion of the Universe).
These questions concerning the origin of the Cosmos also involve a detector which is shortly to be installed outside the ISS, International Space Station: the AMS, Alpha Magnetic Spectrometer.

The AMS detector, installed outside the International Space Station (illustration). Delivery is scheduled for this summer via the last but one space shuttle flight. Credit: NASA

Designed by the Nobel Prize winner for physics, Samuel Ting, in the United States, and 80% financed and built by Europeans, the AMS will be capable, amongst other things, of detecting particles of anti-matter. The results obtained will have a direct influence on the theories linked to the Big Bang. The AMS is to be taken up to the ISS by the last but one space shuttle mission (STS-134) during this coming summer. Astronaut, Roberto Vittori, from the European Space Agency is to take part in this flight.

The AMS undergoing tests on the ground. This impressive alpha magnetic spectrometer weighs in at almost 7 tonnes! The one to be sent to the ISS is known by the name of AMS-02 as a smaller first one (AMS-01) was successfully tested during space shuttle mission STS-91 in June 1998. Credit: NASA

Published on 1 March 2010