Cosmic dust busters aim to clear stellar views

Cosmic dust is fogging up attempts to study light left over from the Big Bang, and Canadian scientists aim to clear up the problem.

The microscopic dust permeates the universe, producing confusing signals in data collected by the Planck space telescope, which is designed to study distant light originating from the beginning of the universe 13 billion years ago.

The dust — mainly sand and soot particles, each about the size of a bacterium — makes up about one per cent of the mass in space, not very much compared with the mass of hydrogen and helium, said University of Toronto astronomer Peter Martin.

"But it does a lot of damage," he added in an interview that airs on Quirks & Quarks Saturday. "It blocks a lot of starlight [and] keeps us from seeing the interiors of gas clouds that are forming stars."

It also interferes with efforts to study "microwave background radiation," the oldest light in the universe.

"Our cosmologist friends would call it 'noise'," Martin said. "It's not blocking [the radiation]. It's adding to the signal and therefore confusing what might otherwise be pure cosmological cosmic microwave background radiation."

Martin and his colleagues are trying to figure out what microwave signal the dust produces as it glows so that signal can be subtracted out of the overall data, leaving behind the pure microwave background radiation.

Ultra-fast spinning particles

In the meantime, they have made some interesting discoveries about the dust itself. Based on the signals they measured, for example, they've found that some of the dust particles are spinning billions of times a second.

That was one of the first scientific results gathered using the telescope, which was launched in May 2009. It will continue collecting data until the end of 2011 from an orbit 1.5 million kilometres from Earth, toward Mars.

Martin thinks the dust is fascinating in itself because it is where heavy molecules generated within stars, such as carbon —  including the carbon that makes up our bodies — has spent most of its existence over the past five billion years.

"When you're talking to your friends, you're talking to people that in an earlier existence used to be this interstellar dust."

The Planck team used its recent news conference to present new data about:

• Twenty galaxies that have never been seen before.
• Cold dust clouds where stars are forming, among the coldest ever discovered.
• Dark gas, a previously undetected type of molecular gas, which has been found clinging to the edges of giant molecular clouds in the Milky Way, and which may have influenced the formation and evolution of galaxies.