Suzanne Kenyon at Dome C, Antarctica, with the AASTINO in the background.

In last year’s Annual Report we told the dramatic story of how, in a battle against time, we designed and built an instrument to measure the atmospheric turbulence over Antarctica. We can now tell you the rest of the tale, in which it is revealed that the instrument, called MASS, exceeded our wildest expectations. But first, some background...

MASS stands for Multi-Aperture Scintillation Sensor, and is a device to measure refractive index fluctuations in the earth’s atmosphere. This phenomenon is of great interest to astronomers who wish to obtain the best view of the distant stars and galaxies, and hence will seek out the best sites to build new telescopes. We had good reasons to believe that the Antarctic plateau would be an excellent site, but to prove it we needed to deploy the MASS experiment. A complicating factor was that MASS had to operate with no humans present, and it had to provide its own electricity, heat, and satellite communications. Fortunately, the last three requirements were met by the AASTINO, a self-contained laboratory that had been previously designed and built in the School of Physics.

In February 2005 the MASS was installed in the AASTINO at Dome C, a remote summer-only station on the Antarctic plateau. Jon Lawrence aligned it using observations of 3 stars, a difficult operation considering that the sun was continuously above the horizon for 24 hours a day. The station closed in mid-February, and our only contact with MASS since then has been via satellite. In April/May/June we took six weeks of data on several bright stars, and the data showed that the atmospheric turbulence was between two and three times less than the best observing sites currently known.

The data from MASS was so impressive that our paper on the topic was published as a Nature Letter in September. Our next goal is to obtain funding for a 2-m aperture telescope at Dome C. Such a telescope would take advantage of the superb conditions there to produce images that would rival those of the Hubble Space telescope.

Michael Ashley, Jon Lawrence,
Suzanne Kenyon and John Storey