Chapter 1

Question 1

meteorites

Answer 1

chemically distinct bits of interplanetary debris

oldest objects found on Earth

Question 2

nebulae

Answer 2

clouds of interstellar gas

Question 3

quasar

Answer 3

a massive and extremely remote celestial object, emitting exceptionally large amounts of energy, and typically having a starlike image in a telescope.

It has been suggested that quasars contain massive black holes and may represent a stage in the evolution of some galaxies.

Question 4

angular distance

Answer 4

the angle formed by lines extending from two points in the sky and intersecting at the observer

Question 5

angular diameter

Answer 5

also known as angular size

the angle which an object “subtends”

Question 6

Estimating angles with a hand

Answer 6

adult hand subtends 10 degrees and the width of a finger 1 degree

Question 7

small angle formula

Answer 7

Linear size (diameter) = (angular size in arcseconds X distance)/206265

Question 8

light year

Answer 8

9.46 x 10^12 km or 63,240 AU

Question 9

astronomical unit (AU)

Answer 9

1.50 x 10^8 km

average distance between the Earth and the Sun

Question 10

parsec (pc)

Answer 10

3.09 x 10^13 km or 3.26 ly

the distance at which 1 AU subtends an angle of 1 arcsec