A cloud of gas that has been excited by light from a nearby star is called ___

In an emission nebula, what is the predominant color of the glow from oxygen?

Compared to a typical nebula, how much more dense is the air we breathe?

Dust clouds that reflect the light of nearby bright massive stars are called ___

Reflection nebulae are composed mainly of ___

When astronomers talk about dust, they mean tiny grains with a width of about ___

"Polycyclic aromatic hydrocarbons" are better known as ___

When visible light hits interstellar dust, what happens to blue and red light?

The dust surrounding the Pleiades star cluster is a ___

Small dust clouds that look like "fuzzy red-edged holes in space" are sometimes called ___

The Orion Nebula is lit by four stars located in its heart, collectively called ___

A flattened disk of dense gas and dust surrounding a young newly forming star is called ___

When viewed in the infrared, what is revealed at the center of protoplanetary disks?

Newly formed stars emit UV light that erodes the surrounding nebula in a process called ___

Three giant towers of gas and dust in the Eagle Nebula have been called ___

The dark nebula in the constellation Orion that is shaped like a gigantic chess piece is called ___

Clouds of dust that look dark to the human eye are actually glowing if you observe them in ___