childrens_illustrated_encyclopedia_template_UK_layer_v4
410
Voyager spacecraft
We have incredible pictures of
the planets and their moons
because space missions have
flown to all of the planets, and
some dwarf planets. Voyager 2
was one of the most successful
interplanetary spacecraft. It
traveled for over a decade
photographing the planets,
and in 1990, made its way out
of the solar system. Voyager 2
made use of the gravity of the
planets to give it an extra push
on its long journey—a similar
effect to stepping off a merry-
go-round while it is moving.Voyager 2 photograph of
Neptune.The two dark blurs
are enormous storms in
Neptune’s atmosphere.Voyager 2 image of Uranus.
Its atmosphere looks blue
because the methane gas it
contains cuts out red light.Image taken by Voyager 1
showing Saturn and its
rings, which consist of
chunks of almost pure ice.Voyager 1 picture of
Jupiter showing the
Great Red Spot, which
is a huge storm.UranUs
Uranus is almost the same size as
neptune and its atmosphere and
interior are also very similar to
neptune’s. Uranus is extremely
cold—about -353°f (-214°c). It
has 13 rings and 27 moons.DWarf planets
some of the largest asteroids
that are big enough to be
spherical are classed as
dwarf planets. ceres in the
asteroid belt is one. the
others are all in the Kuiper
Belt beyond neptune. one
of these is pluto. pluto used
to be classed as a major
planet until 2006, but its
path is more elliptical and
tilted compared with the
orbits of the major planets,
and it is smaller than the
moon. It is now believed
that the dwarf planet eris
is a little smaller in size
than pluto, but more dense.solar system
the solar system
consists of the sun,
planets, moons,
asteroids, and comets.
It formed about
4.5 billion years ago, from
a huge cloud of gas and dust.
the sun’s force of gravity holds
all the planets in their orbits. the
planets are grouped in two bands.
the four small rocky planets belong to the
inner solar system. the four giant planets are spaced
much farther apart and are in the outer solar system.neptUne
neptune (below) has a striking
blue atmosphere of hydrogen,
helium, and methane over a thick
layer of liquid water, methane,
and ammonia, with a rocky
core at the center.
neptune has five
rings and 14
known moons.satUrn
saturn (left) is huge—almost as big
as Jupiter. strong winds blowing
around the planet give its clouds a
banded appearance. It has a solid
core of rock and ice, surrounded by
hydrogen in liquid and gas form. the
planet spins so fast—the rotation takes
only 10 hours—that its poles are noticeably
flattened and its equator bulges outward.
saturn has more than 60 moons.satUrn’s rIngs
Jupiter, saturn, Uranus, and neptune are
all surrounded by rings. saturn’s rings
are the most spectacular, visible from
earth through binoculars. they
consist of countless lumps of almost
pure ice, mixed with a little dust.
astronomers are not sure how
the rings formed. they may have
formed at the same time as the
planet, or may represent the
remains of a large, icy moon
that broke apart.Find out more
astronomy
gravity
moon
sun
UniversePLaNetsNeptuneSaturnEarthSunMercuryMarsVenusJupiterUranusUS_410_Planets_2.indd 410 09/02/16 5:28 pm