Astronomers using Europe's Herschel Space Observatory are asking the public to help find holes in the dust clouds that are threaded through our galaxy. By looking at the images from Herschel, combined with those from NASA's Spitzer satellite, members of the public are invited to join the science effort by helping to distinguish between dense clumps of cold dust and holes in the dusty clouds that are threaded through our galaxy.
Dust clouds don't come in simple shapes, and so the process of distinguishing between dark clouds and holes is incredibly difficult to do. Luckily, the ideal tool is at hand: the human eye.
Observations from the Spitzer satellite show dark regions in the middle of bright clouds of interstellar gas and dust. These were previously assumed to be dense clouds of much colder dust, which Spitzer's infrared cameras cannot see, and which appear silhouetted against the background light.
The Herschel Space Observatory observes far-infrared light, allowing it to see much colder dust than Spitzer. The expectation was that these dark regions would glow brightly in Herschel's images, allowing astronomers to study them in greater detail. The Hi-GAL survey, one of the largest Herschel observing programs, is mapping the entire plane of our galaxy. By observing these far-infrared wavelengths, it is possible to identify much colder regions than with other infrared satellites, and has resulted in a huge number of discoveries -- and surprises.
"We were surprised to find that some of these dark clouds were simply not there, appearing dark in Herschel's images as well," commented Derek Ward-Thompson, from University of Central Lancashire, who is leading this study. "We immediately set about trying to find out how many of these were really there, and how many were holes in space".
The problem proved more complex than the team had anticipated. "The problem is that clouds of interstellar dust don't come in handy easy-to-recognize shapes", Derek explained. "The images are too messy for computers to analyze, and there are too many for us to go through ourselves".
This is where the Zooniverse comes in, with its community of citizen scientists poised ready to help out. The new images are part of the Milky Way Project, which launched 2 years ago and, through the efforts of over 40,000 volunteers, has already created astronomy's largest catalogue of star-forming bubbles, as well as a plethora of nearby star clusters, distant galaxies and more. The Milky Way Project volunteers are excellent at measuring and mapping our galaxy.
"What we've seen across all our projects is that the human brain can classify some images more quickly and reliably than computers can," said Robert Simpson, the Zooniverse lead for this project. "We're delighted to welcome Herschel into the Zooniverse."
"This is Herschel's first citizen science project. It will be exciting to follow the progress in the coming months!" said Goeran Pilbratt, the ESA Herschel Project Scientist.
Dr. Chris North
UK Herschel Outreach Officer
School of Physics and Astronomy
+44 (0)2929 870 537
UK Space Agency
+44 (0)1793 418 069
Prof. Derek Ward-Thompson
Jeremiah Horrocks Institute
University of Central Lancashire
+44 (0)1772 893 829
Dr. Robert Simpson
University of Oxford
+44 (0)7929 508 961
The Milky Way Project:
Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. It was launched in May 2009. The images in the Milky Way Project use data from the SPIRE instrument.
Hi-GAL is the largest open-time key project of the Herschel mission, with almost 900 hours of observing time, in which it is mapping the entire plane of the Milky Way to a width of 2 degrees at 5 wavelengths, from 70 to 500 micrometers. Hi-GAL is run by a Consortium consisting of more than 120 researchers worldwide, with major contributions from Italy, UK, France, USA and Canada. It is led by Dr. Sergio Molinari, of the Instituto Nazionale di Astrofisica (INAF, Italy).
The SPIRE instrument contains an imaging photometer (camera) and an imaging spectrometer. The camera operates in three wavelength bands centered on 250, 350 and 500 microns, and so can make images of the sky simultaneously in three sub-millimeter colors. To do this, the instrument is cooled to 0.3 degrees above absolute zero. The SPIRE instrument has been built, assembled and tested in the UK at The Rutherford Appleton Laboratory in Oxfordshire by an international consortium from Europe, US, Canada and China, with strong support from the Science and Technology Facilities Council.
SPIRE has been developed by a consortium of institutes led by Cardiff Univ. (UK) and including: Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, Univ. Sussex (UK); and Caltech, JPL, NHSC, Univ. Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC, UKSA (UK); and NASA (USA).
Spitzer was launched into space in 2003, as part of NASA's Great Observatories program. The spacecraft travels in an Earth-trailing orbit, and for the first six years of operation was kept at temperatures close to absolute zero using liquid helium. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.
Zooniverse.org is the world's largest and most successful collection of online citizen science projects, which invite everyone to participate meaningfully in scientific research. Since the first project, Galaxy Zoo, went live in 2007 more than 700,000 volunteers have classified galaxies, discovered planets, listened to whales and much more. The Milky Way Project was launched in December 2010 and so far more than 40,000 people have taken part. The result is two peer-reviewed publications: and more are on the way. The Zooniverse.org is supported by the Citizen Science Alliance, a cross-Atlantic collaboration between research universities including Oxford and museums including the Adler Planetarium, Chicago.