Astronomy 3: Earth, Moon, and Sky

Circumpolar constellations:

Ursa Major, Ursa Minor, Cepheus, Cassiopeia, and Draco

The celestial sphere is organized into how many constellations or sectors?

88

Cirumpolar means:

Stars and constellations that circle closely around Polaris

Zodiac Constellations:

On the same plane as the sun, they get “lost in the sun”

Ecliptic:

A circle on the Celestial sphere that represents the sun’s apparent path during the year.

Horizon:

The viewer can only see stars above the horizon. The Celestial Equator is always in the same location on the celestial sphere.

Declination and Right Ascension:

The Latitude and Longitude used in the equatorial grid, used to find stars

Latitude and Longitude

Terrestrial coordinates that locate objects on Earth

Zenith:

The point directly above the viewer’s head.

Nadir:

The point directly below our feet.

Celestial Sphere:

Imaginary globe around the Earth

Polaris:

Point directly above the North Pole. Found on the tip of ursa minor

Solar eclipse:

Occurs when the moon is between the Earth and the Sun

Lunar eclipse:

Occurs when the Earth is between the Sun and the Moon

Umbra:

The inner/darkest part of the shadow during an eclipse.

Pneumbra:

The outer/lighter part of the shadow during an eclipse.

When the moon is waxing…

The illuminated portion of the moon increases nightly.

When the moon is waning…

The illuminated portion of the moon decreases nightly

Tidal forces:

Gravitational forces exerted by a celestial body like the Sun, Moon, or Earth

The Earth has how many tidal bulges?

Two tidal bulges

The tidal bulges are strongest during…

A full moon and a new moon.

Spring tides:

When high tides are stronger and low tides are lower.

Neap tides:

When high and low tides are weaker during the first and second quarter moon phases.

Which two things are very very bright in our night sky?

Venus and the Moon, because of their proximity and reflective nature.

Why do we have seasons?

Because the Earth is tilted and orbits the sun, different hemispheres are tilted towards the sun.

All phases of the Moon:

New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, Waning, Crescent and the New Moon.

Sun-Earth-Moon alignment:

Full Moon, Lunar Eclipse

Sun-Moon-Earth alignment:

New Moon, Solar Eclipse

Sun, Earth, and Moon are at right angles:

First and Second quarter moons

When the moon is waxing it will be lit on…

the right side

When the moon is waning it will be lie on…

the left side

Spring tides occur during the…

full and new moons

Neap tides occur during the…

first and third quarter moons.