Lecture 11 : Solar System and Dwarf Bodies

Question 1

A dwarf planet is a —-1— body that
a) is in –2– around the sun
b) has sufficient –3— for its —4– —– to overcome —5- — forces so that it assumes a —-6—– equlibirum ( –7—– ) shape
c) has not cleared the —-8—- around its orbit
d) is not a —-9—–

Answer 1

1) celestial
2)orbit
3)mass
4) self gravity
5)rigid body
6)hydrostatic
7) nearly round
8) neighbourhood
9) satellite

Question 2

Dwarf planets - —1— confirmed.
Very likely to have more than –2— dwarf planets, most of them in the —3—- —-4——

Answer 2

1)five
2)50
3)Kuiper
4)Belt

Question 3

Trans - Neptunian objects: Small bodies (much larger than —–1——) orbiting beyond the orbit
of —2—–.
> more than —3— known trans-Neptunian objects

Answer 3

1)asteroids
2)Neptune
3)900

Question 4

Pluto’s diameter ~ —1—– km.
Charon’s diameter ~ ——2—– km
➡ Pluto and Charon form a binary system where Charon’s —–3——
pull is not negligible compared to Pluto’s
➡ Pluto has a total of —-4—- moons

Answer 4

1)2300
2) 1190
3) gravitational
4)5

Question 5

Before New Horizons
* Images taken at slightly different orientations showed changes on
the surface of Pluto —> —1—- variation in —-2—- exposure
* As one region receives more light, ice evaporates and then refreezes
onto —-3—- region

Answer 5

1)seasonal variataion
2)sunlight
3)colder

Question 6

ASTEROIDS
Rocky objects ranging between few kilometres up to —1—– km in
diameter.
* Most of them are located between the orbits of —2—- and
—3—

Answer 6

1)1000
2)Mars
3)Jupiter

Question 7

Asteroids
* The density of some asteroids is so low that they cannot be made of —– 1 (two words) —- —> they are made of small —2— joint together due to —3—

Answer 7

1)solid rock
2)fragments
3)gravity

Question 8

Comets
When near the Sun: comets
become —1—.
▪ Sun heats the icy —-2—–,
causing —-3—-.
▪ Sublimation forms:
* Coma.
* Ion tail: created by the —-4—
wind interacting with ions of
the nucleus.
* Dust tail: created from solar
wind and —5—
▪ Comet —6— point —7 — from
the Sun.

Answer 8

1)active
2)nucleus
3)sublimation
4)solar
5)sunlight
6)tail
7)away

Question 9

Meteoroids - Meteors
* A —-1—–is a small object (< 1-5m) moving across the Solar System
* A —2—- is the brief flash of light that is visible when a meteoroid enters Earth’s atmosphere, start
—3—at 50 km high
* As a meteoroid enters the Earth’s atmosphere, the —4– air in front of it heats up to ~ 3000 K producing the bright tail.
* The size of a typical meteoroid is
between a —5– grain and a —6—-
* For objects < 10m wide, the heat
that produces the bright tail also
—7—- it

Answer 9

1)meteroid
2)meteor
3)burning
4)compressed
5)sand
6)pebble
7)vapourises

Question 10

Meteorite
* A meteorite is the piece of rock that has survived the descent through Earth’s —–1—- and has reached the —2—- .
* Meteorites can have traces of the
—3—– of the Solar System

Answer 10

1)atmosphere
2)ground
3)formation

Question 11

Meteor showers
* The dust and —1— fragments left by the tail of a comet are called
—2— swarm
* When Earth’s orbit passes through meteor —3– , a meteor —-4—
is seen as the dust —5—- strike Earth’s upper —-6—–.
* Meteor showers are —-7——.

Answer 11

1)rock
2)meteor
3)swarm
4)shower
5)particles
6)atmosphere
7)periodic