Milky Way Galaxy: 200 Billion Stars and Our Solar System
Earth resides in the Milky Way. It’s home to over 200 billion stars. Our star is of course the sun, which is a main sequence star.
Most stars are at the center of galaxy with few at outer edges. A supermassive black hole is at the galactic center.
On the grand scale, the universe holds a mammoth collection of galaxies like the Milky Way. We know this because we observe them using the Hubble Telescope. Galaxies like the Milky Way are rotating around some point in space likely where the Big Bang occurred.
What shape is the Milky Way galaxy?
Galaxies are flat because things that rotate flatten out on the rotational access. For example, Earth is longer at the equator axis because of its rotation. Similarly, most galaxies are similar to the shape of a discus.
In a clockwise direction, the entire galaxy is rotating as a barred spiral galaxy. Milky Way is a flattened disk with spiral arms. This disk contains dust, stars and gas rotating from a center point.
Based on their visual appearance, Edwin Hubble developed a classification scheme for galaxies. These three classes of galaxies are ellipticals, lenticulars and spirals.
According to the Hubble Galaxy classification scheme, the Milky Way is a SBc barred spiral galaxy. This means that it’s part way between SBb and SBc.
Who are our neighboring galaxies?
We know the closest neighboring star is Alpha Centauri (Rigil Kentaurus)
But the closest galaxy to us is the Andromeda galaxy. This spiral galaxy houses about 1 trillion stars.
So this makes it more than double or even triple the stars compared to the Milky Way.
This Galaxy is on a crash course with the Earth due to its gravitational pulls. But no need to panic because this won’t happen for another 4 billion years.
Are there other habitable planets in the Milky Way?
Lucky for us, Earth is in the Goldilocks zone. This means that it’s within the range where liquid water can persist.
In other words, because Earth receives a hearty portion of sun’s rays, these conditions are “just right” to sustain water and forms of life.
Even here in our Milky Way galaxy, at least 10 habitable planets are within the Goldilocks zone.
For example, Earth’s Doppelgänger might just be in our neighboring star system Alpha Centauri.
This means that only light years away, there is a glimmer of hope that other life can exist.