No GPS, no Google Map - how do astronauts locate in the universe?

Astronomical coordinate system is built based on geographic coordinate system, is an effective tool to help astronauts locate in space.

We are no stranger to GPS and Google Map, tools that tell us where we are on the surface of the Earth, at coordinates. And coordinates are shown by latitude and longitude.

That's how to determine the position on the ground, what about in the universe? That's where GPS can't be used, the surroundings are pitch black, so what to do?

In fact, the way astronauts locate outer space is similar to the Earth, except with a more extensive version. It is called "Astronomical coordinate system".

In the journey of space exploration, when a supernova or small stars are detected and wants people under Earth to observe, astronomical coordinates will be used."The goal is to locate in the sky. It is like the meridian and latitude on the Earth, " said Rick Fienberg, a spokesman for the American Astronomical Association.

Astronomical coordinate system.(Source: Wikipedia).

It is unbelievable that the idea of ​​astronomical coordinates has appeared since ancient times. Its nature is the concept of viewing the sky as a sphere around the Earth, ie the Earth is the center of the universe.

"Although this is completely wrong with reality, that concept helps us build a coordinate system used in the universe," said Christopher Palma, a professor of astronomy and physics at Pennsylvania State University.

Theory of mindfulness gives us the basis to build astronomical coordinates.

So is this "extended version" different from the original version?

It will not have the equator but will have the "celestial equator" - the equatorial projection out into space.

Instead of the latitude, we have the "declination" - measured north or south from the celestial equator. And instead of meridians, we use "chakra" - measured in the east angle to the celestial equator.

This galaxy is called 2XMM J143450.5 + 033843, the numbers after the letter J are its ascension and declination.

Because of the Earth, the universe always rotates, so the degree unit will be replaced by the hour angle. For example, 180 degrees will equal 12 hours of austerity.

Astronauts are not the only ones who have to fall in the astronomical coordinates.Anyone who wants to observe the sky to determine the direction and position can use this coordinate system . Most boats are equipped with GPS, but sailors still need to know the astronomical coordinate system in case the GPS does not work.

"If they see the North Star, they will determine the north, and by some calculations, they will find the remaining directions as well as find their coordinates, thanks to the coordinates of the North Star in astronomical coordinates " - Mr. Fienberg explained.