Science Q & A

How can the Milky Way galaxy be photographed?

New York TimesMarch 23, 2014 

Q. When I see a published photograph purporting to be of the entire Milky Way, I wonder, was it really possible for someone to take it?

A. Many of the photos illustrating the Milky Way are actually top or bottom views of other presumably similar galaxies. An earthbound observer cannot stand outside Earth’s home galaxy and photograph its overall pinwheel structure, with its spiraling arms and central cluster of stars.

Earth is in a corner of what humans see as a diffuse nighttime haze of stars. One model often chosen as a stand-in is the galaxy Messier 74, because many scientists assume its spiral looks the way the Milky Way would look if photographed from above or below its plane. Another stand-in has been the neighboring Andromeda galaxy, or Messier 31.

A satellite image of the Milky Way from within the galaxy shows some indications of its structure. A groundbreaking panoramic view was made in 1990 by the Cosmic Background Explorer satellite, capturing near-infrared wavelengths of light in a time exposure. It shows the central bulge of stars as a bright spot placed at the middle of a thin line that represents the sparser collection reaching out in either direction. If this image were wrapped around the viewer, it would be very close to how an edge-on view of a spiral galaxy would appear.

News & Observer is pleased to provide this opportunity to share information, experiences and observations about what's in the news. Some of the comments may be reprinted elsewhere in the site or in the newspaper. We encourage lively, open debate on the issues of the day, and ask that you refrain from profanity, hate speech, personal comments and remarks that are off point. Thank you for taking the time to offer your thoughts.

Commenting FAQs | Terms of Service