How much of the galaxy is mapped?

The European Space Agency’s Gaia mission is mapping the locations of approximately 1 billion stars in the Milky Way. ESA says Gaia will map 1 percent of the stellar content in the Milky Way, which puts the estimate of the total stars in our galaxy at 100 billion.

How do we know shape of our galaxy?

One gets a rough idea of the shape of the Milky Way galaxy by just looking around–a ragged, hazy band of light circles the sky. That observation indicates that our Milky Way Galaxy is a flattened disk of stars, with us located somewhere near the plane of the disk. Were it not a flattened disk, it would look different.

How much of the universe have we mapped?

The universe has been partially mapped out to about 2 billion light years. Here is a map showing many of the major superclusters within 2 billion light years. If we look far enough across the universe, we can see the faint glow of the Big Bang all around us.

How large is our galaxy compared to others?

Our galaxy probably contains 100 to 400 billion stars, and is about 100,000 light-years across. That sounds huge, and it is, at least until we start comparing it to other galaxies. Our neighboring Andromeda galaxy, for example, is some 220,000 light-years wide.

Is the Milky Way a small medium or large galaxy?

The Milky Way is only a medium sized galaxy with an estimated 200 billion stars. The largest galaxy we know of is called IC 1101 and has over 100 trillion stars.

What is in the center of our galaxy?

At its center, surrounded by 200-400 billion stars and undetectable to the human eye and by direct measurements, lies a supermassive black hole called Sagittarius A*, or Sgr A* for short. The Milky Way has the shape of a spiral and rotates around its center, with long curling arms surrounding a slightly bulging disk.

How do disk stars orbit the center of the galaxy?

How do disk stars orbit the center of the galaxy? They all orbit in roughly the same plane and in the same direction. They follow spiral paths along the spiral arms. They follow orbits that move up and down through the disk, typically taking them about 50,000 light-years above and below the disk on each orbit.