- Education and Science»
- Astronomy & Space Exploration
orrienting yourself in the solar system, galaxy, universe
relationship of galatic plain and path of planets in June
thoughts about my place in the universe
When I look at the night sky, I get curious about where I am in the universe. I have heard of planets, galaxies and other wondrous things, but the night sky is only filled with points of light. This is a bit of a mystery. So, I studied up on how these points of light correspond to the wondrous things I had heard of.
We live within wheels within wheels. We sit on the earth and spin in our social circles. The earth spins. The planets, the earth among them, spin around the sun. The sun spins around the galaxy. I learned there are traces of these arcs in the night sky. In this hub I will share with you what I learned.
You will first have to step a little outside of the human world to see the night sky. City lights and pollution make the stars barely visible.
The rotation of the earth is the most obvious cosmic circle. The sun and stars alternately fill the sky.
If you observe over the course of a year, you will notice that different patterns of stars fill the sky at different times of the year. This is a sign of the next circle, the passage of the earth around the sun.
Now, where to find our brother planets? This too varies through the year, because the earth's axis is tilted. However, the other planets all pass through the constellations that make up the Zodiac. In winter these constellations are higher in the sky than they are are in summer.
The stars in the Zodiac are in the same position at the same time in every season, but the planets move. This is how people discovered the planets; moving stars. Mercury and Venus will always be seen at dawn or dusk, because they are close to the sun. Mercury is not easy to see. Mars, Jupiter and Saturn can appear anywhere in the Zodiac. They have a schedule, but it is complex.
In early summer evenings, Sagittarius is low in the Eastern sky. Behind the center of Sagittarius is the center of our galaxy. The milkyway crosses the plain of the ecliptic at Sagittarius and at Gemini. At this time of year, Gemini is low in the Western sky. In summer, half the disk of the milkyway is high in the night sky. Those of us in the Northern hemisphere, generally, only see this half of the milkyway. The other half is below the horizon.
When when see the milkyway, we are looking through the disk of our local galaxy. When we look towards Gemini, we are looking outwards from our galaxy. South of the milky way, we are looking out from the bottom of the galaxy. North of the milkyway we are looking out the top.
If you are impatient to see the summer sky, stay up late in Spring.
If you think about these things, you can imagine yourself sitting in two plains, tilted with respect to each other. One is the solar system. The other is the plane of our galaxy. The vastness of even larger circles is unimaginable. You can see the nearest galaxy, Andromeda, with binoculars as a smudge of light, if you know where to look. Galaxies themselves are said to have orbits and to make up larger structures, but I have not seen this with my own eyes.
I have been told, and I believe that we and the earth we stand on, are made of dust from long ago, exploded stars. This bit of stardust is amazed to be able to wonder these things.