Astronomy chapter 2

If we have a new moon today, when we will have the next full moon?

.2 weeks

The angular size of your finger at arm's length is about 1°. How many arcseconds is this?

60 x 60 = 3600 arc seconds

We cannot see a new moon in our sky because _________.

A new moon is quite near the sun in the sky

Stars that are visible in the local sky on any clear night of the year, at any time of the night, are called _________.

Circumpolar

Longitude

Distance east or west of the prime meridian, measured in degrees

True or False? Earth is closer to the sun in summer and farther from the sun in winter?

False

Angular measurements

Full circle = 360 degrees 1 degree = 60' (arcminutes) 1' = 60" (arcseconds)

Meridian

Line passing through zenith and connecting N and S points on the horizon

Why do we see phases of the moon?

Lunar phases are a consequence of the Moon's 27.3-day orbit around Earth.

Waxing

Moon visible in afternoon-evening Gets "fuller" and rises later each day

Waning

Moon visible in late night/morning Gets "less" and sets later each day

phases of the moon

New Waxing crescent First quarter Waxing gibbous Full Waning gibbous Third quarter Waning crescent

During the time that a planet is in its period of apparent retrograde motion: _________

Over many days or weeks the planet moves westward relative to the stars rather than usual eastward relative to the stars

Latitude

Position north or south of equator

Which rise in the east and set in the west?

Stars Sun Moon Galaxies

Equinoxes

Sun rises precisely due east and sets precisely due west

If you are located in the Northern Hemisphere, which of the following correctly describes a relationship between the sky and your location?

The altitude of the North celestial pole equals your latitude

How would a star's parallax change as its distance from Earth increases?

The parallax shift decreases as the stars distance from Earth increases

Why do we have seasons on Earth?

The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of year.

How does the orientation of Earth's axis change with time?

The tilt remains about 23.5 degrees (so the seasons pattern is not affected), but Earth has a 26,000-year precession cycle that slowly and subtly changes the orientation of the Earth's axis

It's 9am you look up in the sky and see a moon with half its face bright and half dark. What phase is it?

Third quarter

The North Star (Polaris) is 50° above your horizon, due north. Where are you?

You are latitude 50 degrees N

Horizon

altitude = 0 degrees all points 90 degrees away from zenith

Zenith

altitude = 90 degrees the point directly overhead

Which is NOT using the term "angular size/angular distance" correctly?

angular distance between those two bright stars in the sky is about 2 meters

Lunar eclipses can occur only during a _________.

full moon

Summer solstice

highest path, rise and set at most extreme north of due east

Winter Solstice

lowest path, rise and set at most extreme south of due east

The brightest stars in a constellation

may actually be quite far away from each other

total lunar eclipse

moon passes entirely through umbra

penumbral lunar eclipse

moon passes through penumbra

Solar eclipses can occur only at ________

new moon

partial lunar eclipse

part of the moon passes through the umbra

Solar eclipses can be ____________

partial, total, or annular

Lunar eclipses can be __________

penumbral, partial, or total

constellation

region in the sky as seen from earth

Ecliptic

the path the Sun appears to trace around the celestial sphere each year