AIAA San Francisco Section Newsletter
June 1994

"Planetfall at Pulsar PSR B1257+12"
We Are Not Alone
Brenda Forman

	At long last, It's official:  there are other worlds out 
there.  Puerto Rico's Arecibo Observatory has discovered no 
less than three planets, orbiting a pulsar about 1500 light 
years from earth in the constellation Virgo.

	How about that.

	Now, a pulsar is a most unlikely place to go planet-
hunting since it is the relic of a cataclysmic nova that 
supposedly would have thoroughly incinerated anything in its 
vicinity.  That, however, only makes the discovery doubly 
exciting.  As one expert put it, "If pulsars have planets, 
then almost anything can."

	The Arecibo astronomers haven't actually seen these 
planets, of course.  Even the de-bleared Hubble telescope is 
unlikely to be able to discern such bodies at such distances.  
Instead, the trail of discovery began with some puzzling 
irregularities in the signal from Pulsar PSR B1257+12.  A 
normal pulsar's signal is as maniacally precise as a cesium 
atomic clock, so any such irregularity is bound to pique an 
astronomer's curiosity.  Accordingly, the Arecibo astronomers 
began trying to decipher the cause.  Much study and many 
calculations later, the cause was determined:  the pulsar was 
wobbling slightly under what could only be the gravitational 
pulls of no less then three planets.

	Of course, like every lifelong science fiction fan, I've 
always been convinced that planets were plentiful.  People 
who insist that our solar system is unique have always 
reminded me of the folks who once called it heresy to say the 
earth revolved around the sun.  Strip away the scientific 
jargon and what's left is essentially a rather fatuous human 
ego trip, for few things could be more conceited than to 
insist that this second-rate star on the fringes of a medium-
sized galaxy could seriously be regarded as the solitary one 
of its kind in so unthinkably vast and varied a universe.

	Only studious inattention could sustain such conceit, 
for we are surrounded by an astounding creation -- at once 
dazzling and daunting, intensely beautiful and heart-
chillingly remote.  Consider the star-studded depths of the 
night sky, the glittering pinwheel of a spiral galaxy, the 
engulfing blackness in which our solar system floats.  These 
challenging images proclaim that we are part of something 
hugely greater -- and immensely stranger -- than anything we 
commonly admit.

	Intellectual modesty is all the more fitting inasmuch as 
we remain largely ignorant of both the nature and makeup of 
the strange and glorious universe we inhabit.  For all our 
study and observation, we still aren't quite sure how old it 
is.  We don't know exactly how fast it is expanding.  We 
don't even know what it is actually made of since all the 
stars, gas and dust clouds we can observe do not account for 
more than a fraction of the mass we know has to be there.  So 
we posit the notion of "cold, dark matter," much as we once 
posited the existence of the "cosmic ether."  But in truth, 
we don't know what it might be or even if it actually exists.

	But now we do know that there are other worlds. And if 
other worlds, then possibly other forms of life as well.  
They may be as strange as the worlds upon which they occur, 
but they are a distinct possibility.  It is yet a further 
aspect of the human ego trip to loftily assume that only 
earth-like planets can support life -- or that the only 
acceptable definition of "life" is that which an earth-like 
planet can support.  I am put in mind of one of Isaac 
Asimov's sardonic little short stories in which astronomers 
are arguing over whether there could be life on a newly 
discovered distant planet.  The planet, it soon becomes 
clear, is our own Earth.  No, scoff the experts, life on such 
a planet is patently impossible;  there is far too much 
oxygen...

	For now, all we know is that our conceptual universe has 
been expanded by the addition of three new worlds orbiting a 
star whose hellishly explosive collapse undoubtedly fused 
their surface to solid lave.  If they ever harbored life of 
any sort, that catastrophe surely obliterated it.  But the 
mere existence of planets around so inhospitable a star means 
that our solar system has companions throughout the universe.  
And I am consumed with curiosity.  Where are they? What do 
they look like?  What are they made of?  When will we know?  
After years of reliance on intuition, faith and logic, the 
evidence is in at last.  The universe has always been 
unutterably beautiful.  Now it seems just a little less 
lonely.