The Short Answer:
A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity.
We live on a planet called Earth that is part of our solar system. But where is our solar system? It’s a small part of the Milky Way Galaxy.
A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems. A galaxy is held together by gravity. Our galaxy, the Milky Way, also has a supermassive black hole in the middle.
When you look up at stars in the night sky, you’re seeing other stars in the Milky Way. If it’s really dark, far away from lights from cities and houses, you can even see the dusty bands of the Milky Way stretch across the sky.
The Milky Way galaxy fills the night sky in this photo. Credit: NPS/Dan Duriscoe
There are many galaxies besides ours, though. There are so many, we can’t even count them all yet! The Hubble Space Telescope looked at a small patch of space for 12 days and found 10,000 galaxies, of all sizes, shapes, and colors. Some scientists think there could be as many as one hundred billion galaxies in the universe.
This is a picture taken by the NASA’s James Webb Space Telescope showing thousands of galaxies. This image covers a patch of sky approximately the size of a grain of sand held at arm’s length by someone on the ground. The universe is a very big place! Credit: NASA, ESA, CSA, and STScI
Some galaxies are spiral-shaped like ours. They have curved arms that make it look like a pinwheel. Other galaxies are smooth and oval shaped. They’re called elliptical galaxies. And there are also galaxies that aren’t spirals or ovals. They have irregular shapes and look like blobs. The light that we see from each of these galaxies comes from the stars inside it.
Sometimes galaxies get too close and smash into each other. Our Milky Way galaxy will someday bump into Andromeda, our closest galactic neighbor. But don’t worry. It won’t happen for about five billion years. But even if it happened tomorrow, you might not notice. Galaxies are so big and spread out at the ends that even though galaxies bump into each other, the planets and solar systems often don’t get close to colliding.
article last updated July 13, 2022
FAQs
The Short Answer: A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity. We live on a planet called Earth that is part of our solar system.
What is a galaxy in space place? ›
A galaxy is a huge collection of gas, dust, and billions of stars all held together by gravity. All galaxies are made up of these same things. However, they come in many different shapes and sizes.
What is a galaxy NASA kids? ›
Galaxies consist of stars, planets, and vast clouds of gas and dust, all bound together by gravity. The largest contain trillions of stars and can be more than a million light-years across. The smallest can contain a few thousand stars and span just a few hundred light-years.
What is galaxy and universe for kids? ›
A galaxy is a group of stars, clouds of gas, and dust particles that move together through the universe. There are billions of galaxies in the universe. They probably formed billions of years ago, soon after the universe began. The Sun, Earth, and the other planets of the solar system are part of the Milky Way galaxy.
How are galaxies formed in NASA? ›
The Role Of Dark Matter
Computer models that scientists have made to understand galaxy formation indicate that galaxies are created when dark matter merges and clumps together. Dark matter is an invisible form of matter whose total mass in the universe is roughly five times that of "normal" matter (i.e., atoms).
How many galaxies are there NASA? ›
One such estimate says that there are between 100 and 200 billion galaxies in the observable universe. Other astronomers have tried to estimate the number of 'missed' galaxies in previous studies and come up with a total number of 2 trillion in the universe.
Are we inside a galaxy? ›
Our Sun (a star) and all the planets around it are part of a galaxy known as the Milky Way Galaxy. A galaxy is a large group of stars, gas, and dust bound together by gravity. They come in a variety of shapes and sizes.
What is NASA definition for kids? ›
This article is for students grades 5-8. NASA stands for National Aeronautics and Space Administration. NASA is a U.S. government agency that is responsible for science and technology related to air and space. The Space Age started in 1957 with the launch of the Soviet satellite Sputnik.
What is in space for kids? ›
With no air to scatter sunlight and produce a blue sky, space appears as a black blanket dotted with stars. Space is usually regarded as being completely empty. But this is not true. The vast gaps between the stars and planets are filled with huge amounts of thinly spread gas and dust.
What planet has no moon? ›
Mercury and Venus are the only planets in our solar system without moons (i.e. they do not have any natural satellite).
A galaxy is a sprawling space system which is composed of stars, dust, interstellar gas, stellar remnants, and dark matter and all held together by gravity. The word 'Galaxy' is termed from the Greek word 'galaxies'.
What is a galaxy in space? ›
The Short Answer:
A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity. We live on a planet called Earth that is part of our solar system.
Does every galaxy have a black hole? ›
Summary. Announcing the discovery of three black holes in three normal galaxies, astronomers suggest that nearly all galaxies may harbor super-massive black holes that once powered quasars (extremely luminous objects in the centers of galaxies), but are now quiescent.
How old is the youngest galaxy? ›
Astronomers believe that our own Milky Way galaxy is approximately 13.6 billion years old. The newest galaxy we know of formed only about 500 million years ago.
How many planets are in a galaxy? ›
Doing the math, we can then say that the Milky Way galaxy has – on average – between 800 billion and 3.2 trillion planets, with some estimates placing that number as high a 8 trillion!
What does a galaxy look like? ›
Galaxies also have different shapes. Some are spiral galaxies, like the Milky Way. Some are egg-shaped elliptical galaxies, and the rest are called irregular galaxies. Spiral galaxies have arms shaped like the letter 'S' spiraling out from their glowing centers.
How galaxies are in space? ›
It is estimated that there are between 200 billion (2×1011) to 2 trillion galaxies in the observable universe. Most galaxies are 1,000 to 100,000 parsecs in diameter (approximately 3,000 to 300,000 light years) and are separated by distances on the order of millions of parsecs (or megaparsecs).
