Larry Klaes (email@example.com)
Tue, 13 Jul 1999 16:57:05 -0400
Thursday, July 15 - 8:00 pm: Monthly Observatory Night
for the Public.
"What is New in the Search for Extraterrestrial Intelligence,"
Dr. Robert Stefanik, CfA.
The lecture will be followed by a telescopic observing,
weather permitting. No tickets or reservations are required;
however, seating is limited and filled on a first-come basis.
Doors open at 7:30 pm. Phillips Auditorium.
The Center for Astrophysics holds its monthly Observatory
Night on the third Thursday of every month, featuring a
lecture and, if the skies are clear, telescopic observing.
The next night will be Thursday, July 15, when the speaker
will be Robert Stefanik of the Center who will give a talk
entitled "What is New in the Search for Extraterrestrial
Intelligence." Lectures are free and no tickets are required,
but seating is on a first-come first-served basis. Doors open
at 7:30 p.m. and the lecture begins promptly at 8:00 p.m.
The Observatory Night will be held in the Phillips Auditorium
of the observatory complex at 60 Garden Street. That's about one
mile west of Harvard Square and easily reached by foot or by any
of the buses going down Concord Avenue. There is also ample
free parking in the Observatory lot.
FRIDAY, JULY 16
12:30 pm: Solar and Stellar Physics Division Seminar.
"Primitive Life Creation in the Early Solar System,"
Dr. Alexei Byalko, Landau Institute for Theoretical
Physics, Moscow. Phillips Auditorium. (Anyone wishing to
meet with the speaker should contact Eugene Avrett,
eavrett@cfa, ext. 5-7423.)
Abstract: I discuss the possibility of beginning primitive
life on surfaces of comets and asteroids, of size 100-10,000 m,
in the early solar system 0.1 to 100 Myr after an initial
supernova explosion. Dust condensation in supernova remnants
develops in conditions of decreasing gas temperature.
For T<273 K comets become rich in water and organic compounds.
Their surface temperature is governed by equilibrium between
heat production by radioactivity and thermal radiation from
the surface. (The Sun began to contribute to the thermal balance
only at 50-100 Myr.) The main energy contribution at this stage
is from the isotopes 41Ca(0.14), 60Fe(0.30), 26Al(0.72), and
53Mn(3.70) (decay time in Myr given in parentheses).
Knowing the present isotope abundances from their decay products
we can calculate the "green path" R(t) where the temperature
stays in the range of possible life (270-350K). The life transfer
to bodies of greater size occurs during collisions along this
Additional arguments for life creation at this early stage are:
1) the overall surface area of solar system bodies rapidly
decreases, thus reducing the transfer of such life processes
at later times;
2) the present chiral structure of organic compounds in living
organisms favor such early formation given the chiral asnmmetry
of beta-decay of the isotopes listed above; and
3) the idea of radioactivity as an energy source for primitive
life is a solution of the problem of molecular auto-synthesis,
since initial statistical reproduction could occur due to
splitting of molecular chains by energetic particles.
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