Today, we welcome EPIC 201367065 d to our Goldilocks
list. Perhaps you recall the tale of Goldilocks
and The Three Bears. If so, you
recall how Goldilocks entered the home of the three bears and found three bowls
of porridge sitting on the kitchen table.
Tasting from each bowl, Goldilocks found the porridge of the first bowl
she tasted too hot, the second too cold, but the third bowl of porridge was
just right.
Goldilocks ate the third bowl of porridge.
If you understand the simple temperature-based tale of
Goldilocks and the porridge, you know all that you need to know about
life. Earth, our home planet, is exactly
like the third bowl of porridge. Our
temperature is just right. If our little
blue planet were nudged just a bit nearer to our Sun, we would all burn up and
float away as puffs of gas and smoke. If
pushed a bit farther away from the sun, our oceans and streams would all freeze
solid and at some point all life as we know it would cease. Hence, we reside in the Goldilocks zone,
sometimes called the life zone or habitable zone.
Theoretically, billions of habitable exoplanets (those
outside our own solar system) could exist in Goldilocks zones around Sun-like
stars spread all across the Milky Way.
At present, about thirty such planets have been firmly identified. The nearest of the Goldilocks planets is tau
Cet e. Tau Cet e is 12 light-years distant
from us.
Goldilocks zone planets are being added to the list
regularly. Kepler-186f, at 561
light-years, was added last spring. The
discovery of EPIC 201367065 d, spinning away out there at 147 light-years, was
announced just this January. I find
myself somewhat comforted by the knowledge that these possible homes exist out
there. We may need them. So long as we don’t discover the exoplanets teeming
with aging Elvis impersonators or vacuum salesmen, we have hope.
As a final note, porridge, for anyone interested, is
an equivalent our oatmeal. And I should
note that, technically, Goldilocks was guilty of breaking and entering the
three bears’ residence.
--Mitchell
Hegman Illustration by NASA Ames/SETI
Institute/JPL-CalTech