The Nebula

What's the term for a giant cloud of dust and gas in outer space?

And the answer: a nebula.

Photo courtesy: NASA/JPL-Caltech/University of Colorado.

A nebula is a giant cloud of dust and gases, mostly hydrogen and helium. According to NASA, "some nebulae come from the gas and dust thrown out by the explosion of a dying star, such as a supernova. Other nebulae are regions where new stars are beginning to form."

Coming from the Greek word for "cloud," these fittingly named nebulae are largely invisible to the naked eye, yet are ubiquitous in our universe. The Milky Way, our galaxy, is filled with nebulae of all different shapes and sizes. The Orion Nebula is one of the most visible, and has been observed for thousands of years. In fact, the Maya of Central America called it "the fire of creation."

Almost every part of the lifecycle of a star can be seen in a nebula. These gaseous clouds are so closely intertwined with the life of stars that it is impossible to understand our universe without them. Recent advances in telescopic and infrared technology allow astronomers to peer inside these gaseous clouds to uncover new, striking truths about the nature of stars in our universe.

Infrared detectors work with concentrations of heat and density. These detectors can penetrate a seemingly dark, cold congregation of a nebulae to source signs of increased heat and temperature – oftentimes indicating that a new star is being born. Eventually, the center of the gravity in the nebula grows strong enough to ignite fusion, and a star is born (no, it's not Lady Gaga).

Did you know?  

At the dawn of the universe, around 13.8 billion years ago, the Big Bang gave way to an expanse of pure energy. Over the course of 300,000 years, the energy cooled to form hydrogen and helium gas, lacking solid matter. This means that the entire universe was once one enormous nebula!

Take a trip through a nebula with the video below.

Question of the Day Mobile App


Learn something new everyday. Get the Question of the Day delivered to your inbox each day!

You've successfully subscribed to Question of the Day
Great! Next, complete checkout for full access to Question of the Day
Welcome back! You've successfully signed in.
Success! Your account is fully activated, you now have access to all content.