Astro News Briefs: August 8–14

Mars Reconnaissance Orbiter Launches

August 12, 2005 | NASA's latest Mars mission, Mars Reconnaissance Orbiter (MRO), successfully launched today at 7:43 a.m. EST. At 2,180 kilograms (4,800 pounds) MRO is twice the mass of other recent Mars missions — back to the scale of the ambitious but unsuccessful Mars Observer, whose failure triggered the "faster, better, cheaper" missions of the 1990s. The big spacecraft carries a big camera, the 0.5-meter aperture HiRISE telescope, which will return high-resolution images of the surface as detailed as 1 meter per pixel. It also carries five other instruments along with a 3-meter-wide communications dish to allow a high data rate for sending the pictures back. MRO will reach Mars in March 2006.


"10th Planet" Bigger than Thought?

August 12, 2005 | Due to a Spitzer Space Telescope pointing error, the infrared observatory didn’t actually observe 2003 UB313 as had been previously reported. Astronomers had used the "nondetection" to establish an upper size limit on the largest known Kuiper Belt object. If Spitzer sees the body in follow-up observations scheduled for late August, it could mean that 2003 UB313 is much larger than the original limit of around 3,400 kilometers (2,100 miles). Hubble Space Telescope observations are also in the works.