THE SOUTHWORTH PLANETARIUM
207-780-4249 www.usm.maine.edu/planet
70 Falmouth Street Portland, Maine 04103
"Be it that memory that engenders a poignant ache;
the aroma that
conjures a sense of unfulfilled longing; the setting sun's ember flame
cast on distant clouds; the moment in which that one coveted thing or
desired situation seems forever lost. Don't turn away from it; don't
deny it; don't detest it; or attempt to dilute it. Let it remain.
Stare at it unblinkingly. Smile at it broadly. Feel it fully. Only
then will the potent sorcery within that fleeting moment be made manifest."
THE DAILY ASTRONOMER
Thursday, January 7, 2016
Aliens in Clusters
--------------------------------------------------------------------
"So, Santa brought you a telescope!"
The Southern Maine Astronomers invites you to its meeting tonight at
the Southworth Planetarium.
Did you receive a telescope and want help with the assembly, alignment or usage?
Would you like to learn more about telescopes and how they work?
Attend the SMA meeting tonight
Doors open at 6:30 p.m.
Meeting begins at 7:00 p.m. Free and open to the public.
++++++
And, on Friday, January 8, the Southern Maine Astronomers appear on the
planetarium's weekly radio show "Radio Astronomy" on WMPG 90.9 FM at
1:00 p.m. If you can't attend Thursday evening's meeting, listen to
Friday afternoon's show which will also focus on telescopes.
-----------------------------------------------------------------------------------------
We don't know where the aliens reside.
That one rather unremarkable sentence succinctly summarizes this
entire piece. So, if you find these articles to be intolerable bores
and only read them for credit in the afterlife, consider today's
arduous task wholly fulfilled because all we're really saying today is
We don't know where the aliens reside.
However, Harvard-Smithsonian Center for Astrophysics astronomer Dr.
Rosanne Di Stefano, lead author of a study pertaining to the search
for extra terrestrial life, concluded that globular star clusters
might teem with advanced alien beings. Globular star clusters
are, as their name suggests, globe shaped collections of myriad stars
packed together in a small volume. These massive, star rich globular
clusters are centered around the galactic halo, the spherical region
surrounding the nucleus. Even the least populous clusters contain
tens of thousands of stars. The most populous, such as Omega
Centauri, harbor more than ten million stars.
[If you want to see images of M4 and Omega Centauri, both of which are
heart-breakingly gorgeous, go to the Daily Astronomer web-page:
http://usm.maine.edu/planet/da-7-december-2015 ]
The assertion that globular clusters might thrive with extra
terrestrials is at variance with conventional astronomical wisdom.
Although globular clusters boast rich stellar populations, many
astronomers believe they are almost devoid of planets and therefore
also of extra terrestrial life. First, globular clusters tend to be
quite old, with ages equaling or exceeding 12 billion years. This age
is considered elderly even by the standards of the Universe, estimated
to be about 14.3 billion years old. Such old clusters tend to have
very few heavy elements and, therefore, presumably, few planets, as
they require heavy elements for their formation. In fact,
astronomers have so far found only one globular cluster exo-planet, in
M4, the closest globular cluster to Earth. We should not infer from
this single exo-planet discovery, however, that clusters are planet
poor. Planets are just quite difficult to find in the highly remote
clusters.
Secondly, a globular is densely packed with stars. If the spiral arm
of our home galaxy is a thousand-soul hamlet spread over many square
miles, a globular cluster is a Tokyo subway. Stars are often
separated by less than half a light year. In comparison, Proxima
Centauri, the closest star to our solar system, is 4.2 light years
away. Such close stellar proximity might imbue the clusters with
extreme amounts of radiation.* Such harsh conditions wouldn't be
conducive to life.
On the other hand, Di Stefano and her team pointed out some advantages
globular clusters enjoy in the development of extra terrestrial life.
First, many stars within the globular clusters would have been
massive enough to have exploded as supernovae long ago. These
supernovae both produce and disseminate heavy elements throughout
their regions. They could also trigger new star formation, which
could form stars with retinues of attendant planets. These most
massive stars are short-lived,** and will have already exploded.
Secondly, the higher stellar densities might be beneficial for the
development of more advanced life forms. Imagine different
planets in neighboring solar systems. Life evolves on both worlds.
Presumably, they would both advance to the point of becoming space
faring. As their respective star systems would be so close, they
could conceivably launch missions to each other's systems and in this
manner establish communication, engage in commerce, exchange ideas,
corroborate in the development of more advanced technologies, and
essentially derive mutual benefit from the constant interchange.
(Here, we'll give a nod to the optimists in the audience who would
assume both races would be xenophobic psychopaths hell bent on war,
destruction and mayhem.) These races could then interact with other
nearby races and eventually you would have a Constantinople bazaar
bustling with highly intelligent beings from various star systems.
As globulars are so old, these races would have had plenty of time to
have evolved to this advanced state. By this reasoning, stellar
density and advanced age could actually be conducive to the
development of advanced alien life, as opposed to precluding it
altogether.
The bottom line, of course, is that no aliens have been been located.
We are left to supposition (i.e. guessing) as to where we should look
to find the beings with whom we share this magnificent galaxy. As
for now, we don't know if the races number in the millions or, if
we're alone.
It is one of those truths we can't yet know.
But, what we do know is that
We don't know where the aliens reside.
*At this time, I would like to relax the formality and ask you to
imagine the night sky on a globular cluster planet. Can you
envision anything more lung-collapsingly beautiful than a sky so
replete with stars it almost exudes a pervasive luminescence? A sky
as brilliantly lit and tirelessly dynamic as a metropolitan sky line?
It almost reduces one to desperate tears to think about it....of
course, if you are well adjusted and know the art of proportional
response, the effect will be somewhat more muted.
**The most massive stars have the briefest life spans. The less
massive the star, the longer the life cycle.
|
