Chapter 2 Flashcards
Discover the Universe (29 cards)
Constellation
A region in the sky
88 official ones
Celestial Sphere
The imaginary sphere on which objects in the sky appear to reside when observed from Earth
North Celestial Pole
The point directly over our Earth’s North Pole
South Celestial Pole
The point directly over Earth’s South Pole
Celestial Equator
A projection of Earth’s equator into space makes a complete circle around the celestial sphere
Ecliptic
The path the Sun follows as it appears to circle around the celestial sphere once a year
Local Sky
The sky that can be seen from wherever you are standing
Horizon
The boundary that divides what we can see from what we cannot
Angular Distance (definition)
A measure of the angle from extending imaginary lines outward from our eyes to span an object
Angular Separation (definition)
The measure of the angle between two objects in space
Circumpolar Star
Star’s that remain perpetually above the Horizon circling counter-clock wise around the North Celestial Pole
Latitude
Measures North/South position on Earth
Longitude
The angular East/West distance between the Prime Meridian
Prime Meridian
the meridian of longitude that passes at 0 degrees
Precession
The gradual wobble of the axis of a rotating object around a vertical line
Law of Conservation of Angular Momentum
The initial angular momentum of the system must be the same as the final angular momentum of the system
Earth’s Tilt
23.5 degrees at the Ecliptic Plane
Synchronous Rotation
The rotation of an object that always showed the same face to an object that is orbiting because its rotation period are equal
Lunar Eclipse
When the moon passes through the Earth’s shadow
Solar Eclipse
When the Moon’s shadow falls on Earth
Full Shadow
Umbra, Sunlight is fully blocked
Partial Shadow
Penumbra, light is partially seen/blocked
Total Lunar Eclipse
Moon becomes totally covered by Earth’s shadow
Totality
Part of the Lunar Eclipse during which the Moon is fully within the Earth’s shadow /covering the Sun
