Free
Stand outside on a clear night and look up. You’ll see that there are more stars along the Milky Way (shown above).
Our galaxy looks like a fuzzy gray ribbon of light in the sky. But a low-power telescope gives us a better view. It shows that the Milky Way is made up of countless stars. They are just really, really far away. We can’t see each star by itself with just our eyes.
Astronomers have been looking at the Milky Way with high-power telescopes for the last 200 years. They have found nebulae in many different colors and shapes. Spiral-shaped nebulae are like whole cities of stars. Those are called galaxies. Nebulae can tell us things about how stars developed. That’s because they are part of the birth and death of stars.
▲ Emission Nebula
An emission nebula is a group of gases that glow. The Cat’s Paw Nebula (above) looks like a big paw print. The bright blobs are where clusters of young stars blow bubbles into the cloud. This lights up the gases around them. The gases glow red. When hydrogen gas is hot, it looks red.
Use your mouse or finger to scrub through the animation below.
0%
▲ An artist’s illustration of a nebula
Use your mouse or finger to scrub through the animation below.
0%
▲ An artist’s illustration of a nebula
◀ Reflection Nebula
A reflection nebula is made of dust we can see for this reason: light from nearby stars bounces off it. The Witch Head Nebula (left) glows mainly from light reflected by the bright star Rigel. Rigel is in the Orion constellation. The nebula is blue partly because Rigel is. Also, the dust reflects blue light better than it reflects red light.
▲ Planetary Nebula
A planetary nebula is usually round. Through a low-power telescope, it looks like the disk of a planet. It is really an expanding blanket of gas around a dying star. How did the Eskimo Nebula (above) get its name? To some, it looks like a person’s head surrounded by a parka.
▲ Supernova Remnant
When a massive star runs out of fuel, it explodes. It leaves behind a bunch of newly formed elements. The leftover material is called a supernova remnant. The blast itself is called a supernova. All elements heavier than iron are made in these explosions. The Crab Nebula (above) was discovered in 1731. It lies where a strange bright object was briefly seen in 1054. Astronomers later figured out what the Crab Nebula is. It is the expanding remains of a star that blew up in 1054.
▲ Combo Nebula
In deep-space photographs, it looks like rose petals. The Trifid Nebula (above) gets its name from the dark lanes of dust that split it into three (tri) pieces. The pink area is an emission nebula. The blue area is a reflection nebula. A bright cluster of stars sits in the center. They light up the nebula.
Use your mouse or finger to scrub through the animation below.
0%
▲ An artist’s illustration of a nebula
