Astro News Briefs: August 30–September 5

By: The Editors of Sky & Telescope September 7, 2004 0

SETI False Alarm

September 3, 2004 | Astronomy discussion groups have been abuzz over an article in the September 1st issue of the British magazine New Scientist, titled "Mysterious signals from 1000 light years away." The article describes a possible extraterrestrial signal that has been turned up by the SETI@home project. Alas, the story is unfounded; the signal in question is only what's expected to happen at random from time to time in a data base as massive as SETI@home's. Dan Werthimer, science director of SETI@home, told the BBC "It's all hype. We don't have anything we are excited about." In fact the signal has been correctly described on SETI@home's Web site for many months. For details see the articles posted by the SETI Institute and The Planetary Society.

XingMing Zhou (1965–2004)

September 1, 2004 |Well-known Chinese comet hunter XingMing Zhou died last August 5th from severe head trauma that he sustained in a motorcycle accident near Liancheng in Fujian province. He was 39. Zhou is survived by his wife, Xin Yu, and daughter, Yingzhen.

Zhou was one of the world's most successful discoverers of comets recorded by the SOHO (Solar and Heliospheric Observatory) satellite. He found 63 sungrazing and non-sungrazing comets on images obtained with SOHO's coronagraphs as well as one with the SWAN instrument. The latter has been designated as Comet SWAN, C/2004 H6.

For more information about the life of Zhou, visit Tony Hoffman's Web site.

Fred Whipple (1906–2004)

August 30, 2004 | Fred Whipple, famed astronomer and the originator of the "dirty snowball" theory of comets, died today. He was 97. "Dr. Comet" as he was affectionately called, made a name for himself as an accomplished astronomer long before his groundbreaking 1950 Astrophysical Journal paper entitled "A Comet Model. I. The Acceleration of Comet Encke." In that work Whipple found that Comet Encke had looped around the Sun at least 1,000 times. To survive so many orbits, Whipple proposed that Encke must have been made of a conglomeration of ices. These likely included water, carbon dioxide, carbon monoxide, methane, and perhaps ammonia. Close to four decades later, spacecraft observations of Comet Halley proved that the "dirty snowball" theory was correct — the comet was indeed a frozen nucleus of gases and ice.

Whipple served as the director of the Smithsonian Astrophysical Observatory from 1955 until his retirement in 1973. After that he stayed active in science. At age 92 he was named to the research team for NASA's since-failed Comet Nucleus Tour (CONTOUR), which was to visit Comet Encke among other targets.

President John F. Kennedy awarded Whipple the President's Award for Distinguished Public Service in 1963. He received the prize for his work tracking orbiting satellites. In 1982 the Smithsonian Observatory's facility on Mount Hopkins, Arizona, was renamed the Fred Lawrence Whipple Observatory. Asteroid 1940 is also named in his honor. He is survived by his wife, Babette, two daughters, Sandra and Laura, and son, Earle. The date for a memorial service will be announced in the coming months.

Beagle 2's Postmortem

August 30, 2004 | When the Beagle 2 lander detached from the Mars Express orbiter on December 19, 2003, the bicycle-wheel-size craft was to parachute to the Martian surface and conduct a host of experiments, including a search for fossilized or extant life in the top soil. But after it was released, scientists never heard from it again.

In a report issued by the Beagle 2 team (though not endorsed by the European Space Agency or the United Kingdom's Particle Physics and Astronomy Research Council), mission scientists and engineers speculated why the lander never phoned home. While no specific cause could be isolated as the lone reason for the failure, there are some who believe that models of the Martian atmosphere were incorrect enough to cause a catastrophic failure upon entry. Both the Mars Exploration Rovers and Mars Express missions found the atmospheric density from 20 to 40 kilometers above the surface in early January to be much lower than predicted. Beagle 2 was to enter Mars's atmophere on December 25th. Other problems, such as damage to the lander's antenna upon touchdown, are still possible. To date there has been no sign of Beagle 2 from orbiting spacecraft.

The ultimate gremlin might have been administrative in nature. Beagle 2 was created on a shoestring budget of only 60 million dollars. It was a piggyback component to the Mars Express mission that was forced to meet specific mass and size requirements before being allowed aboard. As the team states in its report, "The primary lesson is, however, that a lander cannot be treated as an 'instrument,' i.e., as an addition to an orbiter. Appropriate priority including funding, schedule, and resources (mass, etc.) must be given to a lander in any future mission."