The SDSS so far can be considered as a sort of transcription process for mapping a three-dimensional scattering of galaxies spread across a 500-square-degree panel of sky onto a 500-gigabyte store of computer data and made universally available for the common good.

Over its 5 year tenure, the survey hopes to log as many as 100,000 quasars. The SDSS data release and quasar results were announced at last week's meeting of the American Astronomical Society in Pasadena.

The Sloan 2.5-meter telescope in New Mexico looks not just out to the edge of the universe but also views foreground objects as well. For instance, in Pasadena, SDSS scientists also reported an inventory of asteroid belt objects orbiting between Mars and Jupiter. Careful color analysis suggests that silicate asteroids preferentially shelter towards the inner side of the belt, at an average orbital radius of 2.8 astronomical units (AU), whereas carbonaceous asteroids circle the sun a bit further out, at an average radius of 3.2 AU. (See Sloan press release, June 5; for a lengthy discussion of the Sloan project see Science, 25 May 2001.)

Meanwhile, another mapping survey, the Two-degree Field (2dF) Galaxy Redshift Survey, using a telescope near Coonabarabran, Australia, announced plans to release on June 30 a sample of 100,000 galaxy redshifts and spectra. (See 2dF press release, June 1.)

(Editor's Note: This story is adapted, with only minor editing, from PHYSICS NEWS UPDATE, the American Institute of Physics Bulletin of Physics News Number 542 June 7, 2001, by Phillip F. Schewe, Ben Stein and James Riordon.)

14-Jun-2001