The planets of the Universe. The soral system

1. ERASMUS 2018-2020
ENEEGYL EGALEO
Inclusion in Secondary School
Mobility in Iasi

2. SOLAR SYSTEM
On line source: https://www.space.com/16080-solar-system-planets.html

3. Mercury
 The closest planet to the sun,
Mercury is only a bit larger than
Earth's moon. Its day side is
scorched by the sun and can
reach 840 degrees
Fahrenheit (450 Celsius), but on
the night side, temperatures drop
to hundreds of degrees below
freezing.
 Discovery: Known to the
ancients and visible to the naked
eye
 Named for: Messenger of the
Roman gods
 Diameter: 3,031 miles (4,878
km)
 Orbit: 88 Earth days
 Day: 58.6 Earth days

4. Venus
 The second planet from the sun, Venus
is terribly hot, even hotter than
Mercury. The atmosphere is toxic. The
pressure at the surface would crush and
kill you. Scientists describe Venus’
situation as a runaway greenhouse
effect. Its size and structure are similar
to Earth. Oddly, Venus spins slowly in
the opposite direction of most planets.
 The Greeks believed Venus was two
different objects — one in the morning
sky and another in the evening.
Because it is often brighter than any
other object in the sky — except for the
sun and moon — Venus has generated
many UFO reports.
 Discovery: Known to the ancients and
visible to the naked eye
 Named for: Roman goddess of love
and beauty
 Diameter: 7,521 miles (12,104 km)
 Orbit: 225 Earth days
 Day: 241 Earth days

5. Earth
 The third planet from the sun,
Earth is a waterworld, with two-
thirds of the planet covered by
ocean. It’s the only world known
to harbor life. Earth’s
atmosphere is rich in life-
sustaining nitrogen and oxygen.
Earth's surface rotates about its
axis at 1,532 feet per second (467
meters per second) — slightly
more than 1,000 mph (1,600
kph) — at the equator. The planet
zips around the sun at more than
18 miles per second (29 km per
second).
 Diameter: 7,926 miles (12,760
km)
 Orbit: 365.24 days
 Day: 23 hours, 56 minutes

6. Mars
 The fourth planet from the sun, is a
cold, dusty place. The dust, an iron
oxide, gives the planet its reddish cast.
Mars shares similarities with Earth: It
is rocky, has mountains and valleys,
and storm systems ranging from
localized tornado-like dust devils to
planet-engulfing dust storms. It snows
on Mars. And Mars harbors water ice.
Scientists think it was once wet and
warm, though today it’s cold and
desert-like.
 Mars' atmosphere is too thin for liquid
water to exist on the surface for any
length of time.
 Discovery: Known to the ancients and
visible to the naked eye
 Named for: Roman god of war
 Diameter: 4,217 miles (6,787 km)
 Orbit: 687 Earth days
 Day: Just more than one Earth day (24
hours, 37 minutes)

7. Jupiter
 The fifth planet from the sun,
Jupiter is huge and is the most
massive planet in our solar system.
It’s a mostly gaseous world, mostly
hydrogen and helium. Its swirling
clouds are colorful due to different
types of trace gases. A big feature is
the Great Red Spot, a giant storm
which has raged for hundreds of
years. Jupiter has a strong
magnetic field, and with dozens of
moons, it looks a bit like a
miniature solar system.
 Discovery: Known to the ancients
and visible to the naked eye
 Named for: Ruler of the Roman
gods
 Diameter: 86,881 miles (139,822
km)
 Orbit: 11.9 Earth years
 Day: 9.8 Earth hours

8. Saturn
 The sixth planet from the sun is known
most for its rings. When Galileo
Galilei first studied Saturn in the early
1600s, he thought it was an object with
three parts. Not knowing he was seeing
a planet with rings, the stumped
astronomer entered a small drawing —
a symbol with one large circle and two
smaller ones — in his notebook, as a
noun in a sentence describing his
discovery. More than 40 years
later, Christiaan Huygens proposed
that they were rings. The rings are
made of ice and rock. Scientists are not
yet sure how they formed. The gaseous
planet is mostly hydrogen and helium.
It has numerous moons.
 Discovery: Known to the ancients and
visible to the naked eye
 Named for: Roman god of agriculture
 Diameter: 74,900 miles (120,500 km)
 Orbit: 29.5 Earth years
 Day: About 10.5 Earth hours

9. Uranus
 The seventh planet from the sun,
Uranus is an oddball. It’s the only giant
planet whose equator is nearly at right
angles to its orbit — it basically orbits
on its side. Astronomers think the
planet collided with some other planet-
size object long ago, causing the tilt.
The tilt causes extreme seasons that
last 20-plus years, and the sun beats
down on one pole or the other for 84
Earth-years. Uranus is about the same
size as Neptune. Methane in the
atmosphere gives Uranus its blue-green
tint. It has numerous moons and faint
rings.
 Discovery: 1781 by William
Herschel (was thought previously to be
a star)
 Named for: Personification of heaven
in ancient myth
 Diameter: 31,763 miles (51,120 km)
 Orbit: 84 Earth years
 Day: 18 Earth hours

10. Neptune
 The eighth planet from the sun,
Neptune is known for strong winds —
sometimes faster than the speed of
sound. Neptune is far out and cold. The
planet is more than 30 times as far
from the sun as Earth. It has a rocky
core. Neptune was the first planet to be
predicted to exist by using math, before
it was detected. Irregularities in the
orbit of Uranus led French astronomer
Alexis Bouvard to suggest some other
might be exerting a gravitational tug.
German astronomer Johann Galle used
calculations to help find Neptune in a
telescope. Neptune is about 17 times as
massive as Earth.
 Discovery: 1846
 Named for: Roman god of water
 Diameter: 30,775 miles (49,530 km)
 Orbit: 165 Earth years
 Day: 19 Earth hours

11. Pluto (Dwarf Planet)
 Once the ninth planet from the sun,
Pluto is unlike other planets in many
respects. It is smaller than Earth's
moon. Its orbit carries it inside the
orbit of Neptune and then way out
beyond that orbit. From 1979 until
early 1999, Pluto had actually been the
eighth planet from the sun. Then, on
Feb. 11, 1999, it crossed Neptune's path
and once again became the solar
system's most distant planet — until it
was demoted to dwarf planet status.
Pluto will stay beyond Neptune for 228
years. It’s a cold, rocky world with only
a very ephemeral atmosphere.
 Discovery: 1930 by Clyde Tombaugh
 Named for: Roman god of the
underworld, Hades
 Diameter: 1,430 miles (2,301 km)
 Orbit: 248 Earth years
 Day: 6.4 Earth day