Hubble has detected a collection of spiral galaxies at various distances from Earth, brought together for a stunning festive image released at Christmas. The largest galaxy in the Hubble Space Telescope image taken on Monday, December 25 is NGC 1356, seen on the right side of the image. This spiral galaxy is located 550 million light-years from Earth and can be seen in the constellation Horoscope.

In the image, NGC 1356 is surrounded by several apparently smaller galaxies with similar spiral morphology. Above the main galaxy is a galaxy known as LEDA 467699, and just to the left of it is LEDA 95415. At the far left of the galaxy trio is another cluster of stars: IC 1947.

The Hubble image is a prime example of how space images can sometimes be misleading. Although these galaxies appear close to NGC 1356 (LEDA 95415 is so close that it appears to be interacting with a smaller galaxy), they are actually very far away in the Universe. This image shows the effect of converting the three spatial dimensions of the universe into a 2-dimensional image. It also shows how powerful Hubble is because it can produce images of galaxies at different distances.

Although NGC 1356 is 500 to 600 million light-years away from Earth, the galaxy with which it appears to be exchanging stars and gas is much farther away. LEDA 95415 is actually 840 million light-years away, which means there is a wide gap between these galaxies of about 290 light-years. (For perspective, the closest star system to Earth is about four light-years away.)

The large distance between NGC 1356 and LEDA 95415 may also explain why LEDA 95415 appears much smaller in the Hubble image than the former. In fact, the two spiral galaxies are probably much closer together in size than they appear.

Just looking at the Hubble Holiday Image, it may appear that the two most distant spiral galaxies in it are NGC 1356 (far right) and IC 1947 (far left), but these galaxies are only two dimensions closer than they appear in the universe. IC 1947 is about 500 million light-years away from Earth, about the same distance as NGC 1356.

Additionally, what appears to be the wide horizontal separation (also known as the angular distance) between two galaxies in the Hubble image is actually about 400,000 light-years away. This makes NGC 1356 and IC 1947, also in the constellation Horoscope, much closer cosmic neighbors than NGC 1356 and LEDA 95415.