1. Compare Nearby and Distant Clusters of Galaxies
Shown below are two clusters of galaxies, one relatively nearby and the other at a distance of about 5 billion light years from Earth. Examine both images to determine the relative numbers of spiral and elliptical galaxies in each. Which galaxy cluster contains a larger fraction of spiral galaxies?
Work in small groups. Divide the image into quadrants and count all the galaxies in each quadrant. Assume that every object in each image is a galaxy.
Abell 851
Distance: 5 billion LY
Credit: Hubble Space Telescope and Alan Dressler
Number of spirals_________
Number of ellipticals_______
Percentage of spirals______
(number of spirals/total counted)
Coma Cluster
Distance: 300 million LY
Credit: NOAO/AURA/NSF
Number of spirals_________
Number of ellipticals______
Percentage of spirals______
(number of spirals/total counted)