Introduction to Space PDF

INTRODUCTION TO SPACE Our Place in the Cosmos Santiago Torres Gil Department of Physics Bachelor’s Degree in Satellite Engineering  1. Our Place in the Cosmos 1.0 Introduction Scales of the Universe ...

INTRODUCTION TO SPACE Our Place in the Cosmos Santiago Torres Gil Department of Physics Bachelor’s Degree in Satellite Engineering  1. Our Place in the Cosmos 1.0 Introduction Scales of the Universe  (m) Range Unit Scale < ≥ Example items Gravitational singularity – – 0 Quantum foam, string ℓP 10−33 10−36 Subatomic proton, neutron, pion 1.0 Introduction am 10−15 10−18 Atomic nucleus fm 10−12 10−15 Wavelength of gamma rays and X- pm 10−9 rays, hydrogen atom 10−12 DNA helix, virus, wavelength of optical Atomic to cellular nm 10−6 10−9 spectrum, transistors used in CPUs 1. Our Place in the Cosmos Bacterium, fog water droplet, human hair's μm 10−3 10−6 human Mosquito, golf ball, cat, violin, football 1 Cellular to mm 10−3 Piano, human, automobile, football 1 m 103 field, Eiffel Tower Mount Everest, length of Panama Human to km 106 103 Canal and Trans-Siberian Railway, astronomical larger asteroid The Moon, Earth, one light-second 109 106 Mm Sun, one light-minute, Earth's orbit 109 Gm 1012 Orbits of outer planets, Solar System Tm 1015 1012 A light-year, the distance to Proxima Centauri Pm 1018 1015 Astronomical Galactic Arm Em 1021 1018 Milky Way, distance to Andromeda Galaxy Zm 1024 1021 Huge-LQG, Hercules–Corona Borealis Great Ym 1027 1024 Wall, Observable universe  1. Our Place in the Cosmos 1.0 Introduction The Blue Marble, Apollo XVII, 1972 1. Our Place in the Cosmos 1.1 Positional Astronomy 1. Our Place in the Cosmos 1.1 Positional Astronomy Celestial sphere  1. Our Place in the Cosmos 1.1 Positional Astronomy Apparent motion of the sky Motion of the stars towards the North celestial pole  1. Our Place in the Cosmos 1.1 Positional Astronomy Motion of the stars towards the North celestial pole 1. Our Place in the Cosmos 1.1 Positional Astronomy Geographic coordinate system Longitude (λ): from 0o at Greenwich to 180o East and West Latitude (φ): from 0o at the equator to 90o North and South at the poles Meridian: great circle at λ=cte Parallel: small circle at φ=cte 1. Our Place in the Cosmos 1.1 Positional Astronomy Altazimuth coordinate system (aka. Horizontal coordinates) Altitude (alt) aka. elevation (el): is the angle between the object and the observer's local horizon, measured from 0° to 90° Azimuth (az): is the angle of the object around the horizon, measured from North and increasing eastward 1. Our Place in the Cosmos 1.1 Positional Astronomy e.g. Satellite Antenna Alignment Satellite Dish Pointer: https://usradioguy.com /dishpointer/  1. Our Place in the Cosmos 1.1 Positional Astronomy Equatorial coordinate system (HA-dec) Hour-Angle (HA): is the angle between the meridian* and the object measured westward LHA: local hour angle from local meridian GHA: Greenwich hour angle from prime meridian Declination (dec, δ) angle measured north (positive) or south (negative) from the celestial equator 1. Our Place in the Cosmos 1.1 Positional Astronomy e.g. Celestial Navigation (before GPS) Latitude: astrolabe, known since Longitude: It requires the use of precise time immemorial, by the ancient chronometers (John Harrison, H1, 1736), Greeks, Persians, and Arabs along with nautical tables  1. Our Place in the Cosmos 1.1 Positional Astronomy Equatorial coordinate system (RA-dec) Right Ascension (RA, α): is the angular distance of a particular point measured eastward along the celestial equator from the Aries point First point of Aries (ϒ; aka vernal equinox): is the location of the March equinox (when the Sun crosses the celestial equator)  1. Our Place in the Cosmos 1.1 Positional Astronomy Sun-Earth geometry 1. Our Place in the Cosmos 1.1 Positional Astronomy Sun motion  1. Our Place in the Cosmos 1.1 Positional Astronomy Planispheres All the objects considered so far have been "fixed stars", i.e., keep almost constant values of RA and dec.  1. Our Place in the Cosmos 1.1 Positional Astronomy Catalogs Common Name, SAO* Num. Const α (2000) δ (2000) Achernar in Eridanus (Alpha), 232481 Eri 01h 37m 43s 57° 14' S Polaris in Ursa Minor (Alpha), 308 UMi 02h 31m 51s 89° 16' N Algol in Perseus (Beta), 38592 Per 03h 08m 10s 40° 57' N Aldebaran in Taurus (Alpha), 94027 Tau 04h 35m 55s 16° 31' N Rigel in Orion (Beta), 131907 Ori 05h 14m 32s 08° 12' S Alnitak in Orion (Zeta), 132444 Ori 05h 40m 46s 01° 57' S Betelgeuse in Orion (Alpha), 113271 Ori 05h 55m 10s 07° 24' N Sirius in Canis Mayor (Alpha), 151881 CMa 06h 45m 09s 16° 43' S Castor in Gemini (Alpha), 60198 Gem 07h 34m 36s 31° 53' N Pollux in Gemini (Beta), 79666 Gem 07h 45m 19s 28° 02' N Regulus in Leo (Alpha), 98967 Leo 10h 08m 22s 11° 58' N Algieba in Leo (Gamma), 81298 Leo 10h 19m 58s 19° 50' N Spica in Virgo (Alpha), 157923 Vir 13h 25m 11s 11° 10' S Alkaid in Ursa Mayor (Eta), 44752 UMa 13h 47m 32s 49° 19' N Alpha Centauri, 252838 Cen 14h 39m 37s 60° 50' S Vega in Lyra (Alpha), 67174 Lyr 18h 36m 56s 38° 47' N Deneb in Cygnus (Alpha), 49941 Cyg 20h 41m 26s 45° 17' N *Smithsonian Astrophysical Observatory Star Catalog 1. Our Place in the Cosmos 1.1 Positional Astronomy Sun apparent motion But bodies within the Solar System change their celestial positions. Ecliptic: The path apparently followed by the Sun Its declination varies between +23°26' and -23°26‘ We find that the Sun's RA increases by approximately 4 minutes a day  1. Our Place in the Cosmos 1.1 Positional Astronomy Solar Analemma  1. Our Place in the Cosmos 1.2 Sidereal and universal time Sidereal and solar day Stars cross local meridian 4’ earlier each night Sidereal day: time period measured w.r.t. fixed stars, 23h 56’ (true Earth rotation period) Solar day: 24h, w.r.t. to the Sun  1. Our Place in the Cosmos 1.2 Sidereal and universal time Local sidereal time Local sidereal time is the RA of the local meridian: LST=HA+RA LST online  1. Our Place in the Cosmos 1.2 Sidereal and universal time Mean and apparent solar time Piazza Dante, Naples Apparent solar time: based on the true position of the Sun on the sky, (sundial) Mean solar time: based on the mean motion of the Sun, (clock)  1. Our Place in the Cosmos 1.2 Sidereal and universal time Greenwich Mean Time Greenwich Mean Time (GMT): is the local mean time at the Royal Observatory in Greenwich, London, counted from midnight. i.e., Noon (12:00:00) GMT is the moment the Sun crosses the Greenwich Meridian Royal Observatory Greenwich Airy Transit Circle Telescope  1. Our Place in the Cosmos 1.2 Sidereal and universal time Coordinated Universal Time Coordinated Universal Time (UTC): time standard successor of the GMT Time zone: área with the same standard time, based on the fact that 15º=1 h Time zones are expressed using positive (towards East), zero (GMT), or negative (towards West) offsets from UTC Time in Spain:  Winter: UTC+01 (CET, Central European Time)  Summer: UTC+02 (CEST, Central European Summer Time) 1. Our Place in the Cosmos 1.2 Sidereal and universal time  Let’s get ready to rumble! stellarium