What is a unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun?
100
What is full moon?
What is the phase of the moon in which its whole disk is illuminated?
100
What is lunar eclipse?
What is an eclipse in which the moon appears darkened as it passes into the earth's shadow?
100
What is nucleus?
What is the central and most important part of an object, movement, or group, forming the basis for its activity and growth?
100
What is rotate?
What is move or cause to move in a circle around an axis or center?
200
What is axis?
What is an imaginary line about which a body rotates?
200
What is galaxy?
What is a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction?
200
What is lunar month?
What is a month measured between successive new moons (roughly 29 1/2 days).
200
What is orbit?
What is the curved path of a celestial object or spacecraft around a star, planet, or moon, esp. a periodic elliptical revolution?
300
What is black hole?
What is a region of space having a gravitational field so intense that no matter or radiation can escape?
300
What is gas giant?
What is a large planet of relatively low density consisting predominantly of hydrogen and helium, such as Jupiter, Saturn, Uranus, or Neptune?
300
What is nebula?
What is a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter?
300
What is phase?
What is a small group of words standing together as a conceptual unit, typically forming a component of a clause?
400
What is comet?
What is a celestial object consisting of a nucleus of ice and dust and, when near the sun, a “tail” of gas and dust particles pointing away from the sun?
400
What is gravity?
What is the force that attracts a body toward the center of the earth, or toward any other physical body having mass. For most purposes Newton's laws of gravity apply, with minor modifications to take the general theory of relativity into account?
400
What is neutron star?
What is a celestial object of very small radius (typically 18 miles/30 km) and very high density, composed predominantly of closely packed neutrons. Neutron stars are thought to form by the gravitational collapse of the remnant of a massive star after a supernova explosion, provided that the star is insufficiently massive to produce a black hole?
400
What is red giants?
What is a very large star of high luminosity and low surface temperature. Red giants are thought to be in a late stage of evolution when no hydrogen remains in the core to fuel nuclear fusion?
500
What is constellation?
What is a group of stars forming a recognizable pattern that is traditionally named after its apparent form or identified with a mythological figure. Modern astronomers divide the sky into eighty-eight constellations with defined boundaries?
500
What is half moon?
What is the moon when only half of its illuminated surface is visible from the earth; the first or last quarter?
500
What is new moon?
What is the phase of the moon when it is in conjunction with the sun and invisible from earth, or shortly thereafter when it appears as a slender crescent?