The primary tools are the compass, a sextant and a chronometer. The compass allows the ship to steer in a specific direction. The sextant is used to measure the angle between the Sun and the horizon. By measuring that at noon, the point the Sun is directly overhead, it allows one to determine the latitude. With a Chronometer and the appropriate tables, the sextant can be used to calculate the latitude and the longitude using the angles of the various stars.
By identifying star patterns, one can determine which way is North (like with ursa minor and the north star).
Also, by knowing the exact time, you can measure the angle of the star above the horizon and calculate a "line of position" on the earth, based on the altitude of the star. Select two other stars and measure their altitude angles, and you will now have three reference "lines of position". Where the lines cross - that's where you are!
Not quite. An astrolabe is a "primitive" version of a sextant or octant, a device which can be used to measure the angular elevation of an object above the horizon. An astrolabe isn't nearly as accurate as a sextant. You could use it to roughly determine your position, but not directions.
Some simple examples:
The astrolabe. See Wikipedia article here: http://en.wikipedia.org/wiki/Astrolabe ________________________ The astrolabe is useful for astronomers, but not so much for navigators. You are referring the the octant, and later, the sextant. An octant is one eighth of a sphere, while a sextant is one sixth of a sphere, and so can measure larger angles.
Sailors often knew the position of the stars at night (like how the northern star is always north) and they would write down which star or constellation they were traveling, so if they go lost, they could use the star's position in the sky to get back home
well not all sailors knew about stars while the navigators needed to know about the stars to navigate the sea so that they could know where they were in relation to different continents such as Asia so that they could get to trade ports
Sailors would have used a few different things for navigation. They may have stayed in sight of land at all times to keep their bearings, or they usually used the stars in the night sky. The main stars used were usually Polaris (the North star) and the stars of the constellation Ursa Minor. Even today there are 57 different stars that are used for navigation both by aviators and sailors worldwide.
Most of the stars we see are so far away that they seem not to move, even over many years. Therefore, they can be used as directional reference points.
The sextant is used in celestial navigation.
yes, the stars are still visible in the original position
A neutron star emits most of its energy at higher frequencies.
When we look at the night sky and see the stars we are only seeing a small part of what is actually being given off by the stars. Stars give off radio waves as well as visible light so radio telescopes are able to detect the radio waves and create maps of the sky based on their locations.
In two hours, the earth rotates us ... and our eyes ... 30 degrees to the east. In order to see the same stars thatwe saw two hours ago, we have to turn our eyes 30 degrees west from the direction where we saw those starsbefore.
An Astrolabe.
The scientist used an astrolabe to find the altitude of the sun and stars.
An astrolabe helped sailors because it could determine any direction based on the position of the stars. This is why the astrolabe helped sailors.
you cant really use any direction to locate the stars
Astrolabes had numerous purposes. At sea, the astrolabe would have been used to calculate one's position in the water based on the position of the sun, stars, or the moon.
They help us to find directions and to locate other stars.
The astrolabe is a very ancient astronomical computer for solving problems relating to time and the position of the Sun and stars in the sky. Several types of astrolabes have been made. By far the most popular type is the planispheric astrolabe, on which the celestial sphere is projected
The astrolabe is a very ancient astronomical computer for solving problems relating to time and the position of the Sun and stars in the sky. Several types of astrolabes have been made. By far the most popular type is the planispheric astrolabe, on which the celestial sphere is projected
These days, an instrument called a "Sextant". Before Columbus, an "Astrolabe".
It is called an astrolabe.
A possible reason the astrolabe was invented was as a means to help predict the positions of the sun and stars for Astrology, which was thought to govern the lives of men.
telescopesA telescope,books to study and find out what types of stars/constellations there are and maybe a astrolabe?