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Help Herschel identify holes in space

Paul Sutherland, Feature writer
Jan 3, 2013, 8:00 UTC

Sen—Everyone is familiar with Hubble. But the space telescope with the largest mirror, 3.5 metres wide, is a European observatory called Herschel.

This mighty instrument observes the Universe in the far infrared region of the spectrum. The writer was fortunate in 2007 to see it as it was being prepared for launch in a clean room at Frederickshafen, in southern Germany. It was only launched in May 2009, by an Ariane 5 rocket from Kourou, French Guiana, yet is already nearing the end of its working life.

Herschel is on borrowed time because the essential coolant needed to allow its instruments to carry out their observations at -271C is fast running out and will be exhausted by March. It cannot be replaced either because this observatory lies 1.5 million km from Earth, orbiting the Sun in resonance with our own planet.

However, the telescope has beamed back a wealth of useful data since it was launched to probe some of the coldest and most distant objects in the Universe.

Its objectives included studying the formation of early galaxies and their evolution, investigating the creation of stars and how they interact with the interstellar medium, observing the chemical composition of the atmospheres and surfaces of comets, planets and satellites, and examining the molecular chemistry of the universe.

Holes in spaceExamples of dark holes being examined in the Zooniverse project. Credit: ESA/NASA

Now space fans are being invited to help analyse some of Herschel's results in the latest citizen science project devised under the Zooniverse label. Professional scientists want them to spot holes in the dust clouds that a spread throughout our Milky Way galaxy.

This is not something that can be done automatically because it is extremely difficult to distinguish between dark clouds and holes in the dust. It is a task that is much better handled by the intelligent eye.

NASA's Spitzer observatory had taken infrared images from space showing dark regions in the middle of bright clouds of interstellar gas and dust. They were assumed to be dense clouds of much colder dust, invisible to Spitzer, which would glow brightly when viewed by Herschel as it mapped the galaxy in its Hi-GAL survey.

Professor Derek Ward-Thompson, of the UK's University of Central Lancashire, who is leading this study, said: “We were surprised to find that some of these dark clouds were simply not there, appearing dark in Herschel’s images as well. We immediately set about trying to find out how many of these were really there, and how many were holes in space."

But he added: "The problem is that clouds of interstellar dust don’t come in handy easy-to-recognize shapes. The images are too messy for computers to analyze, and there are too many for us to go through ourselves."

The Zooniverse team of more than 40,000 volunteers have already worked on the web to discover new galaxies, find star-forming bubbles and make other discoveries.

Robert Simpson, who is leading this Zooniverse project, said: "What we’ve seen across all our projects is that the human brain can classify some images more quickly and reliably than computers can. We’re delighted to welcome Herschel into the Zooniverse.”

To take part yourself, go to the Zooniverse Milky Way Project site.