Picture of the Andromeda Galaxy Next to the Moon-Fiction!
Summary of eRumor:
A picture that was supposedly taken without a telescope that shows the Andromeda Galaxy next to the moon has gone viral.
The Truth:
This photo shows how the Andromeda Galaxy would look in the night sky if it were brighter — but it’s not an actual picture taken without a telescope.
In reality, you can actually see (and probably photograph) the Andromeda Galaxy with the naked eye, but it looks nothing like the brightly colored galaxy in the picture.
Andromeda Galaxy is roughly 2 million miles away from Earth, and it’s the most distant object that you can see in the night sky with the naked eye. However, it appears as a “dim, fuzzy star” with the naked eye. With binoculars, the elliptical shape of the galaxy can be made out, according to UCLA page that describe astronomical objects that can be seen from Los Angeles.
The image that has been making the rounds online has clearly been doctored. This NASA image of the Andromeda Galaxy was overlaid on this image of a night sky that was posted on Flickr by an amateur photographer.
However, there’s a catch. The doctored image shows what the Andromeda Galaxy could look like in the night sky if were brighter. Phil Plait, an astronomy writer for Slate, described the relevance of the image back in January 2014:
The picture shows the crescent Moon in the sky, and superposed near it is the Andromeda galaxy, the nearest big spiral to our own Milky Way. The caption varies from site to site, but generally says that this is how big the Andromeda galaxy would actually look in our sky if it were brighter. Here’s the picture:
And I have to say, that looks about right to me! Andromeda is one of the very few galaxies you can see with your naked eye from a dark site. It’s easy in binoculars, and if you use a small telescope, the galaxy fills the eyepiece.
However, that’s just the core, the nucleus, of Andromeda. Like the Milky Way, Andromeda has vast spiral arms that extend well out from the core. From Earth, the galaxy appears to be more than 3 degrees across — remember, there are 90 degrees in a right angle, and 360 degrees in a circle; astronomers use angular size as a way to measure how big an object is on the sky.
The Moon is about 0.5 degrees across (about half the width of your thumb held at arm’s length), so Andromeda is about six times bigger—roughly what’s shown in the picture. It may not be exact, but I don’t think it’s that important that it be perfect. It’s close enough, and certainly is an amazing thing to consider.
So, the image of Andromeda Galaxy next to the moon was likely created to provide scale and perspective for how large the galaxy would appear in the night sky from 2.5 million light years away if it burned brighter. This image does not actually show Andromeda Galaxy next to the moon in the night sky — but it does have at least some scientific relevance.