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Mighty Mice
an iridescent white, silver, and blue swirl in a black sky speckled with starsThe Telescope’s new Advanced Camera for Surveys (ACS) snapped this image of NCH4676, a pair of colliding galaxies. Nicknamed "The Mice" due to their long tails of stars and gas, the two galaxies are destined to merge into one giant mouse.

This is the first image taken of The Mice that shows so much detail. The left galaxy shows a bright blue cluster of hot young stars formed by the tidal forces of gravity between the two galaxies. The stars in the long, straight tail (upper right) are separated by fainter regions. The faint regions suggest that the star clusters formed from the collapse of gas and dust (brought on by the collision of the two mice) that once occupied those areas. We can see similar conditions and luminous masses surrounding our own galaxy.

This cosmic collision raises questions about our own galaxy. Is the Milky Way doomed to someday collide with our nearest neighbor, Andromeda? Astronomers say maybe. But don’t duck and cover just yet. This cosmic collision isn’t expected to happen for another 3 billion years.

Image courtesy NASA.

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