willner@cfa.harvard.edu (Steve Willner) (11/17/86)
In article <8611171047.AA09235@s1-b.arpa>, ESG7@DFVLROP1.BITNET writes: > On another > subject the TAU (Thousand Astronautical Unit) spacecraft smacks of being > a boondoggle. Who in his right mind would want to fund a multimillion > dollar spacecraft that literally goes nowhere? My understanding was that a prime objective of TAU would be to measure stellar parallaxes, thus directly determining the distance for any visible object in the Milky Way Galaxy (or at least a good fraction thereof). This seems to me to be a worthwhile objective. > An even better mission would be a Pluto orbiter. This would also be a good mission. Setting priorities is hard. I would want to see adequate studies to determine costs and benefits of these and any competitive missions. > I've always thought that Pluto might well be > an example of a "rogue planet" which was created outside of the solar > system. ... > Both Triton and Pluto have very irregular > orbits, and Pluto does intersect with Neptune's orbit. Actually, the current orbits do not intersect, because Pluto's orbit plane is inclined by about 16 degrees with respect to Neptune's. There has been speculation that the orbits might have intersected in the distant past, but the calculations are very difficult and in any event depend on knowledge of any massive bodies in the outer solar system. It seems unlikely that the orbits could ever have intersected, but I don't think it can be ruled out completely. > On any event > this TAU mission strikes me as a misuse of limited planetary exploration > funds. If TAU is primarily an astrophysics mission, I assume it would be paid for out of very limited astrophysics research funds. Balancing research funding between these scientific areas is certainly a difficult job. Steve Willner Phone 617-495-7123 Bitnet: willner@cfa1 60 Garden St. FTS: 830-7123 UUCP: willner@cfa Cambridge, MA 02138 USA Telex: 921428 satellite cam