NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)
Some 500 million light-years from Earth, a seal plays in a cosmic sea.
Or maybe you see a grasshopper as astronomers saw while gazing through earth-bound telescopes. UGC 4881, also known as “The Grasshopper,” is a dramatic view of two merging galaxies from NASA‘s Hubble Space Telescope.
Explore the image. Dozens of other background galaxies can be seen. Zoom in on the center of UGC 4881. The cores of the parent galaxies are distinct but are clearly overlapping. Astronomers believe these galaxies are halfway through their merger. Zoom out and follow the tail as it spirals out into space. The curly tail glows blue with the light of star clusters full of hot, young stars. The flurry of star formation is a result of the interactions between the galaxies. Streams of gas and dust are stretched and pushed together. Some areas of gas and dust come together to form stars. Astronomers noticed a supernova explosion in this galaxy in 1999. Supernovae occur in young stars with mass 10 to 50 times larger than our Sun. These stars are short-lived and burn through their hydrogen and helium fuel at very high-rates. Eventually, when they can no longer sustain nuclear reactions in their cores, they collapse on themselves and rebound in spectacular explosions. The light from a supernova can easily outshine an entire galaxy for a short time. Heavier elements such as gold and silver are created.
Galactic mergers are surprisingly common even when distances between galaxies are very great. Gravity brings the galaxies together in a dance that lasts billions of years. The ultimate result of the collision is the formation of a larger, elliptical galaxy.