- are minor planets 
- is a small rocky or metallic body 
travelling through space 
- are significantly smaller than 
asteroids 
- is an icy small Solar System body 
that, when passing close to the Sun, 
heats up and begins to outgas, 
displaying a visible atmosphere or 
coma, and sometimes also a tail
- comprises 
the Sun and 
the objects 
that orbit it, 
whether they 
orbit it 
directly or by 
orbiting other 
objects that 
orbit it 
directly.
Sun is the star at the 
center of the Solar System. 
It is almost perfectly 
spherical and consists of 
hot plasma interwoven with 
magnetic fields.
-is the closest planet to the 
Sun and the smallest 
planet in the Solar System. 
-has no natural satellites. 
0.4 AU from the Sun 
0.055 Earth masses
-has a thick silicate mantle 
around an iron core. 
-a substantial atmosphere 
- It is much drier than Earth 
0.7 AU from the Sun 
0.815 Earth masses
- is the largest and 
densest of the inner 
planets. 
- the only place where 
life is known to exist. 
1 AU from the Sun
- It possesses an 
atmosphere of mostly 
carbon dioxide. 
- peppered with vast 
volcanoes. 
- Its red color comes from 
iron oxide (rust) in its soil. 
1.5 AU from the Sun 
0.107 Earth masses
- are small Solar System 
bodies composed mainly of 
refractory rocky and metallic 
minerals, with some ice. 
- occupies the orbit between 
Mars and Jupiter. 
- classified as small Solar 
System bodies. 
Ceres -is the largest asteroid, a protoplanet, 
and a dwarf planet. 
-was considered a planet when it was 
discovered in 1801. 
-It was classified as a dwarf planet in 
2006.
- It is composed largely of 
hydrogen and helium. 
- has 67 known satellites. 
5.2 AU from the Sun 
318 Earth masses
- distinguished by its 
extensive ring system 
- has 62 confirmed 
satellites 
9.5 AU from the Sun 
95 Earth masses
- is the lightest of the outer 
planets 
- It has a much colder core 
than the other gas giants 
and radiates very little heat 
into space 
- has 27 known satellites 
19.2 AU from the Sun 
14 Earth masses
- It radiates more internal 
heat, but not as much as 
Jupiter or Saturn. 
- has 14 known satellites 
- Neptune is accompanied 
in its orbit by several 
minor planets, termed 
Neptune Trojans. 19.2 AU from the Sun 
14 Earth masses
- is a great ring of 
debris similar to the 
asteroid belt, but 
consisting mainly of 
objects composed 
primarily of ice. 
- can be roughly 
divided into the 
"classical" belt and the 
resonances.
- A dwarf planet 
- in 1930, it was considered 
to be the ninth planet; this 
changed in 2006 with the 
adoption of a formal 
definition of planet. 
- is the largest known 
object in the Kuiper belt. 
- is the largest satellite 
of the dwarf planet 
Pluto. 
- may also be referred to 
as (134340) Pluto I
Tidesare periodic rises and falls of large bodies of water. Tides 
are caused by the gravitational interaction between the Earth and the Moon. 
The gravitational attraction of the moon causes the oceans to bulge out in 
the direction of the moon. Another bulge occurs on the opposite side, since 
the Earth is also being pulled toward the moon (and away from the water on 
the far side). Since the earth is rotating while this is happening, two tides 
occur each day.
Tide changes proceed via the following stages: 
• Sea level rises over several hours, covering the 
intertidal zone; flood tide. 
• The water rises to its highest level, reaching high 
tide. 
• Sea level falls over several hours, revealing the 
intertidal zone; ebb tide. 
• The water stops falling, reaching low tide.
Isaac Newton 
(1642 -1727) was 
the first person to 
explain tides 
scientifically. His 
explanation of the 
tides (and many 
other phenomena) 
was published in 
1686, in the 
second volume of 
the Principia. 
Spring tides are especially strong tides (they do not have anything 
to do with the season Spring). They occur when the Earth, the Sun, and the Moon 
are in a line. The gravitational forces of the Moon and the Sun both contribute to 
the tides. Spring tides occur during the full moon and the new moon.
Proxigean Spring 
Tide is a rare, unusually high 
tide. This very high tide occurs 
when the moon is both unusually 
close to the Earth (at its closest 
perigee, called the proxigee) and in 
the New Moon phase (when the 
Moon is between the Sun and the 
Earth). The proxigean spring tide 
occurs at most once every 1.5 
years. 
Neap tides are 
especially weak tides. They 
occur when the gravitational 
forces of the Moon and the 
Sun are perpendicular to one 
another (with respect to the 
Earth). Neap tides occur 
during quarter moons.

ASTRONOMY

  • 5.
    - are minorplanets - is a small rocky or metallic body travelling through space - are significantly smaller than asteroids - is an icy small Solar System body that, when passing close to the Sun, heats up and begins to outgas, displaying a visible atmosphere or coma, and sometimes also a tail
  • 9.
    - comprises theSun and the objects that orbit it, whether they orbit it directly or by orbiting other objects that orbit it directly.
  • 10.
    Sun is thestar at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields.
  • 11.
    -is the closestplanet to the Sun and the smallest planet in the Solar System. -has no natural satellites. 0.4 AU from the Sun 0.055 Earth masses
  • 12.
    -has a thicksilicate mantle around an iron core. -a substantial atmosphere - It is much drier than Earth 0.7 AU from the Sun 0.815 Earth masses
  • 13.
    - is thelargest and densest of the inner planets. - the only place where life is known to exist. 1 AU from the Sun
  • 14.
    - It possessesan atmosphere of mostly carbon dioxide. - peppered with vast volcanoes. - Its red color comes from iron oxide (rust) in its soil. 1.5 AU from the Sun 0.107 Earth masses
  • 15.
    - are smallSolar System bodies composed mainly of refractory rocky and metallic minerals, with some ice. - occupies the orbit between Mars and Jupiter. - classified as small Solar System bodies. Ceres -is the largest asteroid, a protoplanet, and a dwarf planet. -was considered a planet when it was discovered in 1801. -It was classified as a dwarf planet in 2006.
  • 16.
    - It iscomposed largely of hydrogen and helium. - has 67 known satellites. 5.2 AU from the Sun 318 Earth masses
  • 17.
    - distinguished byits extensive ring system - has 62 confirmed satellites 9.5 AU from the Sun 95 Earth masses
  • 18.
    - is thelightest of the outer planets - It has a much colder core than the other gas giants and radiates very little heat into space - has 27 known satellites 19.2 AU from the Sun 14 Earth masses
  • 19.
    - It radiatesmore internal heat, but not as much as Jupiter or Saturn. - has 14 known satellites - Neptune is accompanied in its orbit by several minor planets, termed Neptune Trojans. 19.2 AU from the Sun 14 Earth masses
  • 20.
    - is agreat ring of debris similar to the asteroid belt, but consisting mainly of objects composed primarily of ice. - can be roughly divided into the "classical" belt and the resonances.
  • 21.
    - A dwarfplanet - in 1930, it was considered to be the ninth planet; this changed in 2006 with the adoption of a formal definition of planet. - is the largest known object in the Kuiper belt. - is the largest satellite of the dwarf planet Pluto. - may also be referred to as (134340) Pluto I
  • 23.
    Tidesare periodic risesand falls of large bodies of water. Tides are caused by the gravitational interaction between the Earth and the Moon. The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon. Another bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on the far side). Since the earth is rotating while this is happening, two tides occur each day.
  • 24.
    Tide changes proceedvia the following stages: • Sea level rises over several hours, covering the intertidal zone; flood tide. • The water rises to its highest level, reaching high tide. • Sea level falls over several hours, revealing the intertidal zone; ebb tide. • The water stops falling, reaching low tide.
  • 25.
    Isaac Newton (1642-1727) was the first person to explain tides scientifically. His explanation of the tides (and many other phenomena) was published in 1686, in the second volume of the Principia. Spring tides are especially strong tides (they do not have anything to do with the season Spring). They occur when the Earth, the Sun, and the Moon are in a line. The gravitational forces of the Moon and the Sun both contribute to the tides. Spring tides occur during the full moon and the new moon.
  • 26.
    Proxigean Spring Tideis a rare, unusually high tide. This very high tide occurs when the moon is both unusually close to the Earth (at its closest perigee, called the proxigee) and in the New Moon phase (when the Moon is between the Sun and the Earth). The proxigean spring tide occurs at most once every 1.5 years. Neap tides are especially weak tides. They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth). Neap tides occur during quarter moons.