Observational Astronomy Fact Sheet[V7] The content in this document, with rare exception, is an aggregation of astronomical information from several websites. If you find problems or have recommendations for additional data, please contact
[email protected] or visit or visit somewhereville.com/astronomy-fact-sheet. Getting Around The Night Sky Images from blog.simulationcurriculum.com/articles/2015/5/15/measuring-distances-in-the-sky. From horizon to horizon (eg., East-to- West, North-to-South) through the zenith (the point directly above you), the sky is divided into 180 degrees. Your hand can be used to estimate angular distances. Check for yourself - compare with measured distances for the Big Dipper (right). Right Ascension And Declination The entire sky, divided into two parts. Right ascension (blue) begins at the vernal equinox (at far right, at the intersection of the ecliptic (red) and the equator (green)) and increases eastward (towards the left). The lines of right ascension (blue) from pole to pole divide the sky into 24h, each equivalent to 15°. Declination (green) begins at the equator (green) and is positive northward (towards the top) and negative southward (towards the bottom). The lines of declination (green) divide the sky into small circles, here 15° apart. For orientation, the yellow box at left contains the tea pot of Capricorn. The yellow box at right contains the body of Orion. Image (recolored) and text taken directly from en.wikipedia.org/wiki/Declination and en.wikipedia.org/wiki/Right_ascension (on 17 Oct 2016). Moon And Planets MERCURY VENUS EARTH MOON MARS JUPITER SATURN URANUS NEPTUNE Mass (x 1024 kg) 0.33 4.87 5.97 0.073 0.642 1898.0 568.0 86.8 102.0 Equatorial Diameter (km) 4879 12,104 12,756 3475 6792 142,984 120,536 51,118 49,528 Polar Diameter (km) 4879 12,104 12,714 3475 6752 133,708 108,728 49,946 48,682 Avg.