Download The magnificent seven

The magnificent seven
The discovery of seven Earth-like planets orbiting a small star in our galaxy called Trappist-1 is the most recent – and arguably the most spectacular – going back 20 years.
Presence of
water possible
in certain zones.
Possibly habitable planets: These are located in the
habitable zone, the area around the parent star where
a rocky planet is most likely to have liquid water.
TRAPPIST-1:
A red dwarf
star, 10 times
smaller and
2.5 times
cooler than
our own Sun.
b
d
c
e
f
g
h
Orbit
NOTE: Distances not drawn to scale. Illustration of planets is relative.
WHAT WE KNOW
• 39 light years away
(368 trillion km), which
is close by astronomical
standards. The Milky
Way galaxy alone is
100,000 light years
across.
• A probe like
the Voyager 1
would take
700,000 years
to reach the
system.
• Found using the
“transit method” in
which scientists study
tiny dips in light from
the star caused by
the planets passing
across its face.
• Under the right
atmospheric conditions, all
of the seven planets could
have liquid water, but the
chances are highest with
the three (planets e, f and g)
in the habitable zone.
• In 1995, the first planet
was found orbiting a star
like our Sun outside our
solar system. A recent
study estimated that
there are a trillion in
our galaxy alone.
• The most common
type of star is the
cool red dwarf, so
astronomers are
likely to find similar
planetary systems in
the coming years.
An artist’s impression of the surface of one of the planets.
Sources: NASA, AGENCE FRANCE-PRESSE PHOTOS: NASA/JPL-CALTECH, EPA STRAITS TIMES GRAPHICS