Earth, Sky and Seasons
They are measured either north or south of the equator from 0o to 90o.
What are latitudes?
It's the most fundamental astronomical unit of time.
What is the day?
It's the next brightest object in the sky after the sun. It does not produce its own light.
What is the moon?
Twice-daily phenomena which are directly influenced by the moon's gravitational pull.
What are tides?
This occurs when the moon passes completely into Earth's shadow.
What is a lunar eclipse?
These are used to measure positions in the sky.
What are declination and right ascension?
It must keep track of time over the course of long spans, allowing people to anticipate the cycle of the seasons and to honor special religious or personal anniversaries.
What is a calendar?
It's the phase when the moon is fully illuminated.
What is the full moon?
This celestial body produces tides on Earth, though less effectively than the moon.
What is the sun?
This term describes the darkest central region of a shadow where light is completely blocked.
What is the umbra?
What is the Earth's tilt on it's axis?
It is defined in terms of the rotation period of Earth with respect to the stars.
What is a sidereal day?
This is the phase of the moon when it is in the same general direction in the sky as the sun.
What is the new moon phase?
When the Moon is at right angles to the Sun, these lower-than-normal tides occur.
What are neap tides?
During this type of solar eclipse, a ring of sunlight remains visible around the Moon's edge.
What is an annular solar eclipse?
At this location, the sun will appear at the zenith of an observer on June 21.
What is the Tropic of Cancer?
It is based on the average value of the solar day over the course of the year.
What is mean solar time?
It's the phase of the moon that comes right after the first quarter phase.
What is the waxing gibbous phase?
This scientist's theory of gravity first provided a satisfactory explanation for tidal movements.
Who is Newton?
The speed at which the Moon's shadow sweeps across Earth's surface during an eclipse.
What is approximately 1,500 kilometers per hour?
This is how long a day is at the north and south pole.
What is 6 months?
He reformed the Julian calendar to be more accurate.
Who was Pope Gregory XIII?
It's the kind of rotation that allows the moon to always keep the same face pointing towards Earth.
What is synchronous rotation?
The maximum vertical distortion of Earth's surface due to tidal fores is approximately this many centimeters.
What is 20 centimeters?
The path of the Moon's orbit is tilted by this many degrees relative to Earth's orbital plane.
What is 5 degrees?