Natural Sciences- ASTRONOMY

5. - 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

9. - comprises
the Sun and
the objects
that orbit it,
whether they
orbit it
directly or by
orbiting other
objects that
orbit it
directly.

10. 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.

11. -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

12. -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

13. - is the largest and
densest of the inner
planets.
- the only place where
life is known to exist.
1 AU from the Sun

14. - 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

15. - 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.

16. - It is composed largely of
hydrogen and helium.
- has 67 known satellites.
5.2 AU from the Sun
318 Earth masses

17. - distinguished by its
extensive ring system
- has 62 confirmed
satellites
9.5 AU from the Sun
95 Earth masses

18. - 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

19. - 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

20. - 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.

21. - 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

23. 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.

24. 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.

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
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.