Quiz 3

Annular Eclipse

ring of light round dark moon at mid eclipse; new moon is crossing the node and is at or is near apogee

Lunar Eclipse

the moon enters Earth's shadow due to its orbital motion; full moon crossing the node and is visible from the night side of earth

Solar Eclipses

the moon's orbital motion drags its shadow across earth

Total Eclipse

the sun is totally blocked at mid eclipse; new moon crossing the node and is at or is near perigee

full moon

If today is June 21st, and the moon is at the location of the Winter Solstice along the ecliptic, what is the phase of the moon?

Perigee

point in an orbit that is closest to the earth

Apogee

point in an orbit that is farthest from earth

Sidereal Period

one lunar revolution around the earth with respect to the stars

Synodic Period

one lunar revolution with respect to the phases

Moon Rotation

one rotation per revolution, resulting in the same side always facing earth

14 days

About how many days must elapse between first-quarter moon and third-quarter moon in the same cycle?

80x

How much more massive is the Earth compared to the Moon?

(a) Full (b) First Quarter (c) Waxing Gibbous (d) Waxing Crescent

Identify the phases of the moon if at sunset in the Northern Hemisphere the moon is: (a) near the eastern horizon, (b) high in the southern sky, (c) in the southeastern sky, (d) in the southwestern sky.

(a) New (b) Full (c) First Quarter (d) Third Quarter

Identify the phases of the moon if on March 20 the moon is located at the point on the ecliptic called: (a) the vernal equinox, (b) the autumnal equinox, (c) the summer solstice, and (d) the winter solstice.

A lunar eclipse cannot occur on Oct. 13 of the same year because the moon cannot orbit and cross the node so quickly after a solar eclipse. A solar eclipse also cannot happen on Dec. 28 of the same year because a solar eclipse happens roughly every 6 months.

If a solar eclipse occurs on October 3: (a) Why can't there be a lunar eclipse on October 13 of that same year? (b) Why can't there be a solar eclipse on December 28 of that same year?

The moon will be near Spica again on March 29. The moon will be full again on March 31. These values are not the same because sidereal and synodic periods have different lengths of time.

If on March 1 the Moon is full and is near Famous Star Spica, when will the Moon next be near Spica? When will it next be full? Are these values the same? Why or why not?

waxing crescent

If the moon is seen about 45 degrees east of the setting sun, what is its phase?

You would see a waxing gibbous moon.

Tonight you see a waxing crescent moon. Seven days from now, which phase will you see if the night sky is clear?

waning gibbous

What is the phase of the moon between full and last quarter?

first quarter

What is the phase of the moon that rises at local noon?

moon is new the moon is crossing the ecliptic (node) the moon is at or is near perigee in its orbit

What three conditions are necessary for a total solar eclipse?

At dawn, you would see a full moon, waning gibbous moon, third quarter moon, or waning crescent moon. At midnight you would see a first quarter moon, waxing gibbous moon, full moon, or third quarter moon.

Which lunar phases would be visible in the sky at dawn? At midnight?

A solar eclipse only happens if a new moon passes between the sun and earth and the moon's shadow sweeps over Earth's surface along the path of totality. This doesn't happen every new moon because the new moon doesn't pass between the sun and earth every single time.

Why do solar eclipses happen only at new moon? Why not every new moon?

Moon's Orbit

an orbit that is an ellipse around the earth