“ (BBC) One of Europe's great astronomical ventures is coming to a close.

The Planck telescope, put in space to map the oldest light in the Universe, has run out of the helium coolant that keeps it in full working order.

Engineers expect the observatory's systems to start to warm from their ultra-frigid state in the coming days, blinding one of its two instruments.

Nonetheless, Planck has gathered more than enough data since its launch in 2009 to complete its mission goals.

"We have had a flood of data - much more data than originally anticipated, and now we are in the frantic phase," revealed Jan Tauber, the European Space Agency's (Esa) Planck project scientist.

"In a year's time we have promised to deliver our maps and scientific papers, so we are feeling some pressure," he told BBC News.

Planck's quest has been to survey the Cosmic Microwave Background (CMB) - the "first light" to sweep out across space once a post-Big-Bang Universe had cooled sufficiently to permit the formation of hydrogen atoms.

Before that time, scientists say, the cosmos would have been so hot that matter and radiation would have been "coupled" - the Universe would have been opaque.

The CMB pervades the entire sky, and scientists can measure tiny temperature variations in it to glean information about the age, contents and shape of the cosmos.

Two American satellites have already done this, but Planck is much more sensitive and can make much more detailed maps, with higher resolution.

To do this, some of its light detectors have had to operate at the astonishingly low temperature of minus 273.05C - just a tenth of a degree above "absolute zero", the lowest temperature theoretically possible in the Universe…”

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