Buzz Aldrin Returns to
CAS
Morrison Planetarium is pleased to welcome former Apollo astronaut,
Buzz Aldrin as guest lecturer on July 7, 2000 at 7:30 pm. Mr.
Aldrin will speak about the future of space exploration and his
new novel, The Return, written with John Barnes. After
the lecture, Mr. Aldrin will sign copies of his book. Please do
not bring other souvenirs for autographing as Mr. Aldrin will
only sign copies of his book. For more information, check
http://www.calacademy.org/planetarium/special.htm#Dean,
or call (415) 750-7141.
Because of the popularity of this event, tickets will be limited
to five per request. To request advance tickets, please send a
self-addressed, stamped envelope to:
Buzz Aldrin, Morrison Planetarium
California Academy of Sciences
Golden Gate Park
San Francisco, CA 94118.
Sugar and Salt
Sky & Telescope's News Bulletin for June 16, 2000 has two
articles that point to a celestial spice rack.
Radio astronomy researchers have discovered glycolaldehyde, a
simple sugar molecule with eight atoms, in interstellar space.
Jan Hollis, an astronomer working with a 12-meter-wide radio telescope
atop Kitt Peak in Arizona, claims that the discovery of glycolaldehyde
in a giant interstellar cloud known as Sagittarius B2, a dense
cloud of gas and dust some 26,000 light-years away in the direction
of the galactic center, strongly suggests that the chemical precursors
of life are synthesized in these dense clouds long before the
gas and dust collapses to form stars and planets.
The Zag meteorite, which fell in Morocco in August 1998, contains
tiny crystals of halite—ordinary salt. Geochemists have now
found that Zag’s halite crystals are more than 4.5 billion
years old, and in fact date to within two million years of the
oldest known minerals in the solar system. James Whitby and his
team used an analysis of the isotopes xenon-129 and argon-40 to
determine the ancient age. These trace isotopes are both radioactive
decay products. The researchers postulate that the presence of
halite in Zag indicates the existence of brine even earlier. The
salt was left behind when the water evaporated. The extremely
ancient salt crystals suggest that, according to Whitby, “the
formation of 10-kilometer-sized planetesimals—necessary to
provide conditions suitable for liquid water—must have occurred
faster than was hitherto thought.”
Now then, if we had some flour, butter, and apples, we could have
our pie in the sky!