■ Russell Grigg
ON 23 February 2017, NASA reported their discovery of the first known system of seven Earth-sized planets around a
single star,1 namely the red dwarf star
TRAPPIST-1 (see box). These planets
are identified in order of their distance
from their star as TRAPPIST-1: b, c, d,
e, f, g, and h. Their sizes compared to
Earth range from 76% to 113% of Earth’s
diameter, but there the similarity ends,
and there is very little else about them
that is like Earth. Claims that they are
covered in oceans of water are fallacious,
despite hugely imaginative artist’s illus-
trations, published by NASA.
NASA originally claimed that “three
of these planets are firmly located in the
[so-called] habitable zone”: d, e, and f.1
This is the zone where water can remain
liquid—not too hot so that it all boils away,
and not too cold so that it all freezes. It
is thus also called the ‘Goldilocks zone’.
However, further research showed that d
was too hot and f was too cold, and that
even the remaining planet e likely could
not have liquid water either.
Obstacles for life
For a planet to be favourable for life, it’s
not enough for it just to be in the ‘
habitable zone’ of its star—it must stay there.
So it needs an almost circular orbit as
our planets have, not a highly eccentric orbit like comets. But most known
exoplanets have more eccentric orbits
than even Mercury’s, the most eccentric
of our planets. 2
Also, the term ‘habitable zone’
carries misleading connotations. Liquid
water is necessary but not sufficient!
Although essential for biochemical
NONE SUITABLE FOR LIFE!
NASA has released this artist’s concept of the seven Earth-sized planets orbiting TRAPPIST-1 compared to the four rocky
planets of our Solar System. The use of blue and green hues suggesting the presence of water and vegetation on the TRAPPIST-1
planets is misleading.
CREATION.com 49 Creation 39( 3) 2017