The return of 6344 P-L won’t light up network switchboards over the weekend, but it’s something to ponder, particularly in light of recent Arecibo happenings. 6344 P-L was first found in 1960 on photographic plates made with the 48-inch Schmidt instrument at Palomar Observatory. The discovery team, working at Leiden Observatory in the Netherlands, had found several thousand asteroids, but this one, recognized as a potential danger to Earth, had not been re-identified until now.
Under its new name of 2007 RR9, the object remains curious. It is one of almost 900 asteroids bigger than 150 meters in diameter that close within 0.05 AU of Earth’s orbit, and observations now indicate it may not be an asteroid at all. SETI Institute astronomer Peter Jenniskens, whose re-discovery of the object was recently confirmed, thinks we’re dealing with something else, a dormant comet. Says Jenniskens:
“This is a now-dormant comet nucleus, a fragment of a bigger object that, after breaking up in the not-so-distant past, may have caused the gamma Piscid shower of slow meteors… that is active in mid-October and early November.”
Dormant comets brighten as they move toward the Sun, and this one should brighten in southern hemisphere skies as we move into mid-October. Will 2007 RR9 ever pose a threat to Earth? The question is problematic, since having just re-discovered it, we have much to learn about its orbit.
Learning things about potentially hazardous objects is something that Arecibo’s planetary radar does quite well, so note the following: The National Science Foundation’s astronomy division has announced that the Arecibo radar will be closed later this month. Cornell University’s
National Astronomy and Ionosphere Center manages the facility for
the NSF. From a letter by Wayne Van Citters, director of the division, referring to budgetary pressures:
Cornell has said that it will cease operations of the planetary radar in October 2007 to meet these budget reductions. We have recently learned that, in fact, they are maintaining the capability to operate the planetary radar, although on a less frequent schedule. In conversations with NASA management, it has been made clear that NASA has no intention of resuming support of the planetary radar, which they terminated in FY 2006.
While Cornell and Arecibo staff pursue business and academic partnerships to provide new support, a bill has been introduced into the US House of Representatives to ensure the continued operation of the Arecibo Observatory for both astronomical and radar-imaging purposes. Congressman Dana Rohrabacher, a co-sponsor of the bill, understands what’s at stake:
“Arecibo is a key resource in understanding the characteristics of potentially hazardous asteroids and comets so that they can be dealt with effectively. There is no room for error when it comes to eliminating a threat that could kill millions.”
The House also goes to work on October 11 in a Congressional hearing dealing with a controversial NASA report on Near Earth Objects. How best to detect and, if necessary, deflect them? Surely the Arecibo situation will hover over these proceedings as well. Another question looms for the rest of us: How best to convince the public that a sustainable search for Earth-crossing objects may be crucial for long-term survival?