Cosmiverse.com; Sept 25, 2000; Space News: "Pluto-Kuiper Express May be Scrapped"

Space.com; Sept 25, 2000; Science News: "Scientists Ask NASA and Congress to Rescue Imperiled Pluto Mission"

Pluto/Charon

Work has officially stopped on the financially troubled Pluto-Kuiper Express (PKE) mission (09.01.00 NewsNotes: Pluto Probe Procrastination) so that it can be reconfigured.  The fate of the $350-million mission to study Pluto, its moon Charon, and objects-beyond came into question when cost rose to $500-million.  NASA spokesman Don Savage said that "the mission will be deferred until they can re-plan it for what's affordable."  But the savings realized by sidetracking PKE spells relief for another mission: the Europa Orbiter mission that had seen a similar escalation in costs.  NASA associate administrator Ed Weiler told a House of Representatives subcommittee meeting on September 13 that the Europa Orbiter had a higher priority than PKE (See why in 09.01.00 NewsNotes: Promising Presence).  He said: "Basically, I directed the project to go full speed on Europa to give us the earliest possible launch of that mission." 

Scientists fear that the work stoppage will not allow enough time for a reconfigured Pluto mission to be included in NASA's space launch schedule for 2004 -- the original launch date.  Timing is critical for this mission for two reasons: firstly it relies on a gravity assist from Jupiter, and secondly Pluto's atmosphere could be frozen over (is now moving toward the farthest point in its orbit) if the arrival date is pushed much past 2012.  Scientists were eager to inspect Pluto's atmosphere for clues to that planet's formation.  Pluto is the only planet not to have been visited by space probes.

Preparation-A(steroid) Revisited 

UK Task Force on Near Earth Objects; Sept 18, 2000; Press Release: "Report Of The Near Earth Objects Task Force Published"

Space Rock

The UK's "Near Earth Objects Task Force" (05.01.00 NewsNotes: Why Not Try Preparation-A) has published its report on the dangers of NEOs and what role the United Kingdom can take in dealing with such objects.  The report noted that asteroids and comets have collided with the Earth in the past to either bringing the essentials of life (carbon and water) or extinguishing life (dinosaur extinction).  It noted that the risk analysis is hampered by incomplete data on objects that pose a threat of Earth impact.  While comets pose less of a risk, their sudden appearance yields less of a lead-time -- 1-year perhaps before impact -- in comparison to asteroids whose orbits can be plotted decades into the future.  Fourteen recommendations were made by the Task Force that include: building a new 3-meter survey telescope in the southern hemisphere to detect NEOs; encouraging the use of space probes to detect objects; rendezvous mission using microsats to visit different NEOs and learn their characteristics; formation of local and international government bodies to deal with NEOs -- including a reorganization of the Minor Planet Center; and studies into mitigating and deflecting NEO impacts.

Square Holes From Round "Pegs"

SpaceScience.com; Sept. 26, 2000; NASA Science News: "Square Craters"

Pair of 1-km Craters

NASA's NEAR-Shoemaker spacecraft has found clues that an extensive system of fractures and faults exist on Near Earth Asteroid 433 Eros.  This result is from analysis of unusual square-shaped impact craters imaged on the space rock.  Scientist noted that the best example of a square crater on Earth is the famous Meteor Crater in Arizona.  The landform there is riddled with an intersecting system of fractures; impacts made on such terrain assume a square shape due to the fractures.  So the analysis leads to a similar landform existing on Eros.

Scientists do not know if the square craters formed before or after Eros -- which is believed to have been part of a larger body -- achieved its present size and shape.  Further imaging may help pin down more information about the history of Eros.  One theory is that in the early history of our solar system a small planet existed between Earth and Jupiter.  A collision with another body created the asteroid belt from which Eros emerged from. 

NEAR-Shoemaker had been orbiting the 33-km long, peanut-shaped, asteroid since February of this year. 

Liquid Looking Glass

Space.com; Sept. 24, 2000; Astronomy: "The Liquid Lens: Telescope Technology Takes a Leap"

UBC LMT Home Page, Website: www.astro.ubc.ca/LMT

University of British Columbia cosmologist Paul Hickson needed observing time on a large telescope to map the position of millions of galaxies.  He calculated that a 5-meter telescope would suffice if he reserved such an instrument for 5-years of straight imaging.  That was never going to happen.  Most astronomers are only able to obtain short observing runs on such instruments.  So he did the next best thing: build his own telescope -- a larger 6-meter one yet.  Once completed it will rank as the 13th largest in the world.  Usually such a large instrument would involve large amounts of money -- $100-million perhaps -- but Hickson is building the instrument for only $1-million.  This amazing 100:1 cost reduction was accomplished by using an 18th century idea: the Liquid Mercury Telescope (LMT).  

It was first noted by Newton in the 18th century that a spinning liquid sloshes toward the sides of its container and forms the perfect shape to focus light to a point.  Over the centuries various experimenters attempted to build such scopes but were foiled by vibrations in the surface of the liquid.  Now Hickson has perfected the methods of reducing vibrations in the liquid to produce a surface comparable to a conventional mirror.  With tremendous cost savings, from not having to precisely figure a hard mirror, the LMT may usher in the day when individual astronomers can each have their own large research instrument.

Hickson built his first successful LMT in 1993 when he constructed a 2.7-meter model.  In 1996 he sold a 3-meter model to NASA for tracking space junk. His next project is taking shape 60-miles east of Vancouver, British Columbia.  Named the Large Zenith Telescope it consists of a 6-meter parabolic bowl of mercury rotating at 5-RPM on air bearings.  Suspended 10-meters above the mirror at the focal point is the imaging system.  This makes for a fast f/1.5 system with 24-arc-minute field of view.  A wooden structure with roll-off roof houses the telescope.  First light is expected later this year.

10/01/2000