NASA: Astronomy Picture of the Day(2023-10-06)

lalaloo 입니다.

This photo is the Astronomy Picture of the Day provided by NASA.

나사에서 매일 업데이트하는 오늘의 우주 모습입니다.

 

Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

이 사진의 제목은 <Edwin Hubble Discovers the Universe> 입니다.

해당 작품의 소유권은 Carnegie Institution for Science 에게 있습니다.

 

How big is our universe? This question, among others, was debated by two leading astronomers in 1920 in what has since become known as astronomy's Great Debate. Many astronomers then believed that our Milky Way Galaxy was the entire universe. Many others, though, believed that our galaxy was just one of many. In the Great Debate, each argument was detailed, but no consensus was reached. The answer came over three years later with the detected variation of single spot in the Andromeda Nebula, as shown on the original glass discovery plate digitally reproduced here. When Edwin Hubble compared images, he noticed that this spot varied, and on October 6, 1923 wrote "VAR!" on the plate. The best explanation, Hubble knew, was that this spot was the image of a variable star that was very far away. So M31 was really the Andromeda Galaxy -- a galaxy possibly similar to our own. Annotated 100 years ago, the featured image may not be pretty, but the variable spot on it opened a window through which humanity gazed knowingly, for the first time, into a surprisingly vast cosmos.