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46 Cards in this Set

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  • Back
The angular distance in degrees of an object north or south of the celestial equator.
The position of an object that is comparable to longitude on Earth; measured in units of hours and minutes
Right ascension (R.A.)
The highest point in the sky at any particular time and location
The fact that we see objects as they were in the past when we look out into space
Look back time
Our star, the Sun, is one of 100 billion stars that form the...
Milky Way Galaxy
Patterns we create in the sky to symbolize important stories and to locate things in the sky
A unit of angular measure equal to 1/360th of a full circle.
The average distance between Earth and Sun.
Astronomical unit (AU)
All evidence indicates that the universe started 13.75 Billion years ago in the...
Big Bang
A large object that directly orbits a star and is massive enough to both become a sphere and to mostly clear out the debris in its orbit
An enormous clumping of thousands of galaxies
Our galaxy is a part of the ___ of about 24 galaxies
Local Group
All the stuff going around our Sun including our own planet and the Sun.
Solar System
The sum total of all space, time, matter, energy, puppy dogs, etc.
All the stuff that we can see that is closer than 13.75 billion ly away.
Observable Universe
the position along the horizon that one should face to see a particular object in the sky
The angular distance above the horizon of a particular object in the sky.
A small object made mostly of ice and a little rock that is orbiting a star.
A small object made mostly of rock, and a maybe some ice, that is orbiting a star.
Most objects in the universe spin. This is called...
One sixtieth (1/60) of a degree
Minute of arc
One sixtieth of an arcminute or 1/3600 = 1/60 · 1/60 of a degree
second of arc
The highest point in the sky at any particular time and location
Earth’s axis is 23.5° off from being perpendicular to our orbit we call this...
Axis tilt
That time when Earth’s northern pole is tipped the most towards the Sun
Summer Solstice
This literally translates as “Sun stop” because the north-south motion of the Sun stops and
goes in the other direction at this time
The Northern Hemisphere time when the Sun crosses the celestial equator heading northward
Vernal Equinox
The apparent path of the Sun against the background stars over the course of a year.
The constellations that fall along the ecliptic. It translates from Greek as “circle of animals.”
The shape of the illuminated portion of the Moon that we see changes, this is the…
Phases of the Moon
The same side of the Moon always faces Earth (ignoring a tiny wobble) this is called…
synchronous rotation
When Earth’s shadow falls on the Moon we call it a…
Lunar eclipse
This happens when the Sun – Moon – Earth are in a direct line (in that order).
Solar eclipse
The darkest part of an object’s shadow, i.e., where the entire light source is blocked.
That part of a shadow where only part of the Sun is blocked from view.
Ancient civilizations had troubles explaining the odd motion of the planets, especially…
retrograde motion
It is difficult to explain the motions of the heavens for a universe that is believed to be…
The main problem with accepting that Earth orbited the Sun was the inability to detect any
shifting in the stars as we orbit the Sun. This apparent shifting of the stars is called…
stellar parallax
Our modern understanding has us at a random spot in our galaxy in a solar system that is…
This happens when the Moon is completely inside the darkest part of Earth’s shadow.
Total lunar eclipse
An educated guess on the part of a scientist as she prepares to study some phenomena
The Greek philosopher who defined our view of the natural world for nearly 2,000
The “Father of Modern Science” who defined what we now know as
“the scientific method.”
He figured out the motion of the planets including that they travel on elliptical paths.
The time required for an object to complete one orbit around the Sun is the ...
The philosophy that simple theories are usually better than complicated ones.
Occam's Razor