Longitude of vernal equinox
Have you ever seen a big globe or a world map? They are pictures of the Earth from above, like if you were in space looking down at our planet. On this map, we can see lines going up and down, and left and right, called longitude and latitude lines.
Longitude lines go up and down, starting from a spot in the middle of the planet called the Prime Meridian. This line is special because it divides the Earth into the eastern hemisphere and the western hemisphere.
Now, let’s talk about the vernal equinox. This is when the day and night are almost exactly the same length (12 hours each) all over the world. It happens twice a year - once in March (the spring equinox) and once in September (the fall equinox).
The longitude of the vernal equinox is the position of the Sun relative to the Prime Meridian at the time of the spring equinox. Just like how we have different time zones because the Earth rotates and the Sun appears to move across the sky, the longitude of the vernal equinox changes a little bit every year.
Scientists and astronomers use the longitude of the vernal equinox to keep track of time and measure distances in the universe. It’s kind of like knowing where you are on a map so you can find your way to different places.
Longitude lines go up and down, starting from a spot in the middle of the planet called the Prime Meridian. This line is special because it divides the Earth into the eastern hemisphere and the western hemisphere.
Now, let’s talk about the vernal equinox. This is when the day and night are almost exactly the same length (12 hours each) all over the world. It happens twice a year - once in March (the spring equinox) and once in September (the fall equinox).
The longitude of the vernal equinox is the position of the Sun relative to the Prime Meridian at the time of the spring equinox. Just like how we have different time zones because the Earth rotates and the Sun appears to move across the sky, the longitude of the vernal equinox changes a little bit every year.
Scientists and astronomers use the longitude of the vernal equinox to keep track of time and measure distances in the universe. It’s kind of like knowing where you are on a map so you can find your way to different places.