This week’s image from the Hubble Space Telescope shows no less than three galaxies that are in the process of merging to become one, called IC 2431. Located 681 million light-years away in the constellation of Cancer, this object shows what can happen when galaxies collide and merge into each other.
The enormous gravitational forces of such a merger pull the galaxies into elongated shapes, though the process isn’t entirely destructive — there is also plentiful star formation happening in parts of the merger, with new stars being born amid the chaos. Some of the most active areas may be right in the middle of the merger, though this can’t be seen in the image as a thick cloud of dust obscures the center.
A notable fact about this object is that it was investigated using one of the earliest and biggest citizen science projects in astronomy. The Galaxy Zoo project, beginning in 2007, is now on its 15th version and has brought together members of the public to help identify and classify galaxies, mergers, and supernovas.
“The original Galaxy Zoo project was the largest galaxy census ever carried out and relied on crowdsourcing time from more than 100,000 volunteers to classify 900,000 unexamined galaxies,” Hubble scientists write. “The project achieved what would have been years of work for a professional astronomer in only 175 days and has led to a steady stream of similar astronomical citizen science projects. Later Galaxy Zoo projects have included the largest ever studies of galaxy mergers and tidal dwarf galaxies, as well as the discovery of entirely new types of compact star-forming galaxies.”
