Since the average person isnât making less than $20,000 per year (which they would be if $3,150 were two monthsâ salary), itâs clear that grandmaâs rule no longer holds. Weâre not saying that you shouldnât buy an engagement ring, but we also donât think itâs wrong to play with conventions every once in a while.
The pinkish-red color of nebulae, such as M42 in Orion or the Lagoon Nebula in Sagittarius, is really a combination of four different bright spectral lines of hydrogen gas. A hydrogen atom has a single proton at its center and a single electron in its outer region.
In some nebulae, stars form out of large clouds of gas and dust; once some stars have formed inside the cloud, their light illuminates the cloud, making it visible to us. These star formation regions are sites of emission and reflection nebulae, like the famous Orion Nebula shown in the picture on the right.ot surprisingly, these are called dark nebulae. Another type of nebula, called a planetary nebula, results from the death of a star. When a star has burned through so much material that it can no longer sustain its own fusion reactions, the star's gravity causes it to collapse.