Astronomy Chapter 1-4 (All solved)

celestial sphere correct answers the apparent surface of the imaginary sphere on which celestial bodies appear to be projected. north celestial pole, star trails, zenith, meridian, celestial equator, RA and DEC meridian correct answers an imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator north celestial pole correct answers The location on the celestial sphere directly above the Earth's northern rotation pole. Sirius correct answers the brightest star in the night sky astronomical unit correct answers a unit of length used for distances within the solar system light year correct answers the distance that light travels in a vacuum in 1 year astronomy correct answers the study of all matter and energy in the universe, its structure, organization and evolution lunar eclipse correct answers the blocking of sunlight to the moon that occurs when Earth is directly between the sun and the moon solar eclipse correct answers occurs when the Moon passes directly between the Sun and Earth and casts a shadow over part of Earth zenith correct answers point in the sky directly overhead; highest point ecliptic correct answers the apparent path of the sun through the stars planet correct answers from the Greek for "wanderers" because these bright "stars" moved with respect to the rest (real stars) on timescales observable by the individual circle correct answers has 360 degrees because of Babylonians estimated 1 yr is about 360 days (this over 3000 years ago) zodiac correct answers a circular diagram representing the 12 zodiacal constellations and showing their signs. -planets move, but stay within about 18 degrees of the ecliptic. Root word is same as Greek for animals (zoo) constellation correct answers A group of stars that form a pattern in the sky. constructed for mnemonic aid. solar day correct answers the period of time from which the sun is directly overhead until the next time the sun is directly overhead. It is 24 hours. sidereal day correct answers the time for one complete rotation of the earth relative to a particular star, about 4 minutes shorter than a mean solar day. 23 hr 56m Heliacal risings correct answers The heliacal rising of a star (or other body such as the moon, a planet or a constellation occurs when it first becomes visible above the eastern horizon for a brief moment just before sunrise, after a period of time when it had not been visible Kepler's 1st law correct answers the orbits of the planets are ellipses with the sun at one foci (nearly circular) Kepler's 2nd law correct answers the line between a planet and the sun sweeps out equal areas in equal times Kepler's 3rd law correct answers square of orbital period increases with cube of semimajor axis (planets farther from the sun move more slowly) conic section correct answers (geometry) a curve generated by the intersection of a plane and a circular cone Newton's 1st law correct answers in the absence of force, objects move in a straight line. Newton's 2nd law correct answers force equals mass times acceleration---the definition of force. The 2nd most famous equation in history: F = ma Newton's 3rd law correct answers action equals reaction, or force equals force. Newton's "4th Law" correct answers • Gravity is universal • Gravity cannot extend undiluted forever, after all, other planets orbit the Sun not the Earth • This leads to Newton's Inverse Square Law Scale of Planet Volumes correct answers • Jupiter would fit 1000 times into the volume of the Sun • Earth would fit 1000 times into the volume of Jupiter • Earth would fit 1 million times into the volume of the Sun retrograde motion correct answers actual or apparent motion of a body in a direction opposite to that of the (direct) motions of most members of the solar system or of other astronomical systems with a preferred direction of motion. As viewed from a position in space north of the solar system (from some great distance above the Earth's North Pole), all the major planets revolve counterclockwise around the Sun, and all but Venus and Uranus rotate counterclockwise on their own axes; these two, therefore, have retrograde rotation. declination (DEC) co