Astronomy Lecture 1

Question 1

Star

Answer 1

Large glowing ball of gas that generates heat and light through nuclear fusion

Question 2

Planet

Answer 2

Moderately large object that orbits a star; shines by reflected light. Rocky, Icy, or gaseous

Question 3

Moon

Answer 3

an object that orbits a planet

Question 4

Asteroid

Answer 4

Relatively small and rocky object that orbits a star

Question 5

Comet

Answer 5

Relatively small and icy object that orbits a star

Question 6

Solar system

Answer 6

A star and all the materials that orbits it, including its planets and moons

Question 7

Nebula

Answer 7

An Interstellar cloud of gas or dust

Question 8

Orion Nebula

Answer 8

about 1350 light years away and and about 13 light years across

Question 8

Astronomical Distance Units

Answer 8

average distance between the Earth and the sun

Question 9

Galaxy

Answer 9

Great island of stars in space, all held together by gravity and orbiting a common centre

Question 10

Andromeda Galaxy

Answer 10

2.5 million light-years away

Question 11

Galaxy Cluster

Answer 11

A group of few hundred to thousand of galaxies

Question 12

Speed of light

Answer 12

300,000km/s