ASTRONOMY 1010-FALL 2018-CELESTIAL NAVIGATION BAD DAY AT SEA: pou are lost the t
ID: 152572 • Letter: A
Question
ASTRONOMY 1010-FALL 2018-CELESTIAL NAVIGATION BAD DAY AT SEA: pou are lost the two primary coordinates that you need to determine are your latitude (the angular north-south distance between Earth's un aoon on Barth y surface) and your longitiude (the anguiar east-west distance betvween the prime meridian and a location on Earth's surface). TITUD, THERE ARE 3 METHoos Cserctrico nEL0wEORTHE NORTHERN HENSPEERE N MOTHOOSZ &31 it is nighetime, then find the north or south celestial pole TO FIND YOURLA Method 1: If is athitude ofcelestial pole (N if you see the morth pole, S (f yow see the south pole) s nightime, then find the alttude above the southern horizon of any star for which you know the decdination. A positive number (below) means that you are in the northern bemisphere anitude (N) 90-(altitude of star above southern horizon)+decnation of star) Methed 3: If it is daytime, then find the altitude above t of the Sun above the southern horizon, and look up the declination of the Sun on that date. A positive number (below) means that you are in the northern hemisphere anitude (N)-90-(altitsde of Sam above southern bortzon)+(declination of Sun on that date) TonND YOUR LONGmpE.COMPARE roURLOCAL TMErmmer rett is Aeon t OCATION Method 1: Compare your local time (eg froem a sundial) with a clock that shows the time in Greenwich, England (aka the UT) ongitude(time dufference in hours) (15/hour). lt is W if your clock is earlier, and E if your clock is later than Greenwich Method : Determine when the San crosses the meridian at your location, and look at a clock that shows the time in a location where you know the longitude longitude diferences (time difference in hours) (15/hour) it is W fyour clock is earlier, and E ifyour clock is later. Add this difference to the longitude at the known locarion Method 3: Compare when a star is on the meridian at your location with the time when that same star is on the meridian at a location with a known longitude. losgitude differences (time difference in hours) (as /hour) tis the longitude at the kmown location if your clock is earlier, and E if your clock is later. Add this difference to Celestial Navigation Probilems: Be sure to show all cakculations clearly and to inchude units Remember that all latitudes must be specifed as N latitude and longitude on a map, such as htps//itouchmap.com/latlong.hem 1. During a vacation, you decide to take a solo boat trip. While updating your Facebook page, you not only rur battery, but you also lose track of your pos aUT clock. You thereby put together the following description of your situation down your cell phone sition Fortunately, you have some astronomical tables and instruments on the boat, as well as It is the spring equinox The Sun is currently on your meridian at an altitude of 70 above the southern horizon The UT clock reads 23-00 a What is your latitude? How do you know? b. What is your longitude? How do you know? c Consult a map (or app). Based on your position, where is the nearest land? Which way should you sall to reach it?Explanation / Answer
The declination of the sun is 0 degrees during solistice.
Altitude of 70 degrees above southern hemisphere
latitude(N)= 90-(altitude of sun above southern hemisphere)+declination of sun.
latitude(N) =90- 70+0 =20 degrees N
The time is calculated to be 10:40 am, as sun rises in east at 6 am during equinox and is vertical at 12:00 noon.
longitude = time diff(23-10.66) *15/4.66
longitude = 39.72 W
23°00'00.0"N 39°43'12.0"W is the location nearest continent is North america North West of the found location.