10.1 Galaxies Flashcards
What does a galaxy consist of?
A galaxy consists of -
1. Stars - usually millions of them
2. Planetary systems - astronomers this that most stars have planetary systems
3. Stellar dust and gas - from either exploded stars or leftover from the formation of the universe
What is our solar system surrounded by?
Our solar system is surrounded by the Kuiper Belt and Oort clouds, which lie beyond Uranus and Neptune. These are frigid zones as very little light reaches them.
Why is it important for a planet to be in the vicinity of a star and in a planetary system?
It is important for a planet to be in the vicinity of a star and in a planetary systems so that it has a stabilized gravitational field.
Why is it important for humans to be close to a star?
It is important for us to be close to a star as a star is an energy source, without which we wouldn’t survive.
What is the name of our galaxy? Describe it.
We live in the Milky Way Galaxy. Most visible stars are in the Milky Way, a spiral galaxy with curved arms forming a disc with a bulge in the middle. Astronomers believe our Sun and other stars in the milky way orbit a massive black hole at the center.
What is the nearest star and solar system to our solar system?
Proxima Centauri, our nearest star, has a diameter seven times smaller than our Sun’s and is orbited by at least one exoplanet, making it our nearest solar system. Both our Solar System and Proxima Centauri are part of the Milky Way galaxy.
Describe some other galaxies in the universe.
The Andromeda galaxy, the nearest spiral galaxy to our own, is a spectacular sight. You can also see two neighboring galaxies, the Large and Small Magellic Clouds. Galaxies, which can be eliptical, irregular, or active, require a telescope for detailed observation as they resemble fuzzy discs with the naked eye.
What is the Universe? Is it finite?
The Universe comprises all existing entities, including stars, planets, moons, comets, asteroids, and meteors, and humans. The outer boundaries of the Universe are unknown due to the possibility of no ‘outside’. Its size and potential infiniteness remain unknown, but we can observe it for 13.7 billion light years in all directions.
