Sky and Telescope - March 2016 - 16

Cosmic Relief
David Grinspoon

Could It Be?
We need to learn how to talk about possible signs of E.T. intelligence.
column (S&T: Jan. 2016,
p. 20), I discussed the lack of evidence for technically
advanced extraterrestrials. Curiously enough, in the
time between writing that and its publication, some possible evidence materialized.
I'm sure you've heard plenty about the star KIC
8462852 (S&T: Feb. 2016, p. 14). The Kepler spacecraft
found that its light is quivering in a complex way, like a
lantern harassed by a large moth. It doesn't match anything predicted or observed around any other star. Something huge - perhaps half the star's diameter - is in
orbit there or passing in its vicinity, at times blocking up
to 20 percent of the starlight. That's no planet. The dips
in the light have come in an irregular pattern, ruling
out a simple orbit and hinting at multiple objects. In the
absence of a well-understood, straightforward explanation, it's reasonable to entertain exotic hypotheses.
It has long been proposed that technically advanced
civilizations should be detectable by their works of
"astroengineering." The quirky character of KIC
8462852 resembles descriptions of "alien megastructures" that one can trace to science fiction going back
at least to Olaf Stapledon in the 1930s. In 1960 Freeman
Dyson described how advanced societies might surround
their stars with enormous solar collectors. Stars hosting
such "Dyson spheres" would appear dim in visible light
but bright with the infrared glow due to waste heat.
Whatever the cause of the odd dips in the light from
KIC 8462852, it's clearly not such a Dyson sphere surrounding the whole star. But until scientists have convincingly explained what's going on, is there anything
wrong with entertaining the provocative thought that it
could be some kind of huge alien construction?
Some scientists and pundits want to condemn that
idea as ridiculous and unworthy of mention. But it
would have been wrong not to consider this enticing possibility for such a strange observation. The correct posture, at this point, is to regard an artificial explanation as
extremely unlikely - but not illogical or impossible.
Perhaps this provides a test case, because we have
to learn how to talk about these things. In the decades
ahead we will be observing more and more exoplanets
with better and better instrumentation (S&T: Oct. 2015,

16

March 2016 sky & telescope

NASA / JPL-CALTECH

In my most recent

Artist's concept of a swarm of comets passing before a star

p. 16). We'll see some novel things, and when we don't
understand them, then biosignatures and even technosignatures are possible explanations, and we should
consider them without going overboard with either
skepticism or credulity. We have to be cautious - but if
we refuse to consider outlandish and wonderful possibilities, we might miss something truly important.
The alien hypothesis has increased the interest with
which scientists are scrutinizing this star. Out of this
will come new knowledge, most likely not about aliens.
Promising plans include making new visible, infrared,
and ultraviolet observations. The next time the light
of KIC 8462852 flickers we can inspect the material
properties of the obscuring stuff: Is it dust? A swarm of
comets? Or something seemingly artificial? Quite possibly it's something nobody has thought of yet.
Perhaps someone will have explained the peculiarities of KIC 8462852's light curve by the time this column
appears in print. On the other hand, the mystery might
endure for years, allowing numerous predictions to
be made and tested. Imagine all the fiction, fantasy,
nonsense, religion, and good science that a possible alien
civilization might inspire if generations go by without a
definitive answer. It would serve as a fluttering beacon
reminding us that we have a lot to learn. ✦
David Grinspoon is an astrobiologist, author, and senior
scientist at the Planetary Science Institute. Follow him on
Twitter at @DrFunkySpoon.



Sky and Telescope - March 2016

Table of Contents for the Digital Edition of Sky and Telescope - March 2016

Contents
Sky and Telescope - March 2016 - Cover1
Sky and Telescope - March 2016 - Cover2
Sky and Telescope - March 2016 - 1
Sky and Telescope - March 2016 - Contents
Sky and Telescope - March 2016 - 3
Sky and Telescope - March 2016 - A
Sky and Telescope - March 2016 - B
Sky and Telescope - March 2016 - 4
Sky and Telescope - March 2016 - 5
Sky and Telescope - March 2016 - 6
Sky and Telescope - March 2016 - 7
Sky and Telescope - March 2016 - 8
Sky and Telescope - March 2016 - 9
Sky and Telescope - March 2016 - 10
Sky and Telescope - March 2016 - 11
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