What in the Universe: Galaxies

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What are the multicolored objects in this space telescope image?

Produced by the Space Telescope Science Institute’s Office of Public Outreach in collaboration with NASA’s Universe of Learning partners: Caltech/IPAC, NASA Jet Propulsion Laboratory, Smithsonian Astrophysical Observatory, and Sonoma State University. 

  • Hubble Space Telescope image of the Hubble Ultra Deep Field (2014): NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI)

Written by Claire Blome 
Designed by Dani Player 
Editorial and design input from Margaret W. Carruthers, Dr. Quyen Hart, Leah Ramsay, and Timothy Rhue II 
Music courtesy of Music for Non-Profits

Red square against starry sky. Icons, star, galaxy, constellation, asteroid, solar system. Text, what in the universe.
Image, space with countless colorful disks and points.
Text, what are these multicolored objects? A., stars, B., planets, C., galaxies, D., black holes.
C is highlighted in grey.
Text, Hubble ultra deep field 2014, Fornax constellation. A galaxy is a collection of gas, dust, dark matter, and billions of stars and planetary systems held together by gravity. Most are thought to have a supermassive black hole at their core.
Researchers can easily identify these objects as galaxies based on their shapes and the number of stars in them.
Spiral galaxies stand out because they are coiled and curved, with a mix of older and younger stars.
Elliptical galaxies have oblong or round shapes, and typically contain older stars.
There are 200 billion to two trillion galaxies in the observable universe.