While astronomers have identified over 500
planets around other stars, they're all too
small and distant to fill even a single pixel
in our most powerful telescopes. That's why
science must rely on art to help us imagine
these strange new worlds.
Even without pictures of these exoplanets,
astronomers have learned many things that
can be illustrated in artwork. For instance,
measurements of the temperatures of many "Hot
Jupiters," massive worlds orbiting very close
to their stars, hint that their atmospheres
may be as dark as soot, glowing only from
their own heat.
While "Hot Jupiters" would be relatively dark
in visible light, compared to their stars,
their brightness is proportionally much greater
in the infrared. Illustrating this dramatic
contrast change helps explain why the infrared
eye of NASA's Spitzer Space Telescope plays
a key role in studying exoplanets.
As our understanding evolves, so must the
artwork. Astronomers found a blazing hot spot
on the exoplanet Upsilon Andromedae b that
at first, appeared to face towards its star.
More data has revealed that the hottest area
is actually strangely rotated almost 90 degrees
away, near the day/night terminator.
WASP 12b is as hot as the filament in a light
bulb, and would be blazing bright to our eyes.
Most interestingly, if it proves to have a
strongly elliptical orbit, as first thought,
calculations show it would be shedding some
of its outer atmosphere into a gassy disk
around its star.
Computer simulations of HD 80606 b, constrained
by global infrared measurements, are helping
astronomers to better understand the details
of how its atmosphere circulates. These computations
can feed back into the artwork helping us
produce more plausible illustrations.
The closest known exoplanet is 10 light years
away in the Epsilon Eridani system. Excess
infrared light found here by Spitzer has led
astronomers to conclude it also has two asteroid
belts, hinting at the possibility of other
small, rocky worlds.
Perhaps the strangest known planetary system
orbits the pulsar PSR B1257+12, the neutron
star remnant of a supernova. Astronomers have
detected three planets that either survived
the explosion, or formed afterwards in this
region filled with spinning magnetic fields
and hostile radiation.
Until the day we can explore other star systems
as thoroughly as our own, exoplanet art inspired
by the real science will help fill in the
gaps in our imagination.