The galaxies that surround us are arrayed so they are seen from all angles- no two are identical in the perspective presented to our line of sight. Those that are shy and only present their profile allow us a compelling view of a facet that would otherwise be undetectable- many are not flat but are slightly twisted!
The scale of the Universe is vast beyond comprehension. For example, galaxies are often called Island Universes because the distance that separates one from the other essentially makes travel between them, even at the speed of light, utterly impossible- even within the lifespan of an entire species. But these distances are superceded because, on its grandest scale, the Universe is organized into huge areas that, remarkably, resemble soap bubbles. Their interiors are seemingly void of material but at the juncture where the bubbles meet, we often find a group of galaxies huddling together. Most galaxies belong to one of these celestial congregations.
The gravity of one galaxy can have an effect on its neighbor in the group and it is believed that some of the warping observed in galaxies, when seen from their edge, is caused by this interaction. Additionally, many galaxies are attended by much smaller companions- each one a galaxy unto itself, but caught by the gravational embrace and forced into an orbit around a larger galactic entity. Over time, even small galaxies, under such circumstances, will tug and affect the shape of their partner.
Investigating these and other explanations stoke the fires that motivate many professional astronomers.
The focus of this picture is a galaxy located 55 million light years in the distance which is very, very far if you remember that one light year is about 10 trillion kilometers! Because we live inside a galaxy, the view beyond our island in space is always through a curtain of stars that is much closer to us. Thus, although the galaxy in this picture has the hardly memorable designation of NGC 4013, because of a coincidence, one of the Milky Way's suns is superimposed on it so that many say it resembles something more familiar- a diamond solitaire ring!
This image presents the galaxy's edge-on appearance so that, horizontally along its central axis, there runs a dark irregular line that resembles craquelé in a old painting. This is actually an enormous amount of material- vast lanes of dust that are the remains of stars previously exploded. Because the dust is light absorbent, it blocks our view of what lies behind. However, it also provides a clue about this galaxy's true nature- notice that the line is curved- dipping at the left and rising a the extreme right.
The reason for this deviation has remained a mystery, however, data from images, like this, have helped give one team of astronomers a new insight (more...).