Topic: hubble

Hubble marks America's 250th with a red, white and blue portrait of a star cluster

• To mark the 250th anniversary of the United States, NASA has released a Hubble Space Telescope image of Messier 3, a dense globular cluster whose stars glow in fitting shades of red, white and blue.
• Beyond the patriotic timing, the cluster is a genuine scientific treasure — home to half a million stars and an unusually rich population of the pulsing 'standard candles' astronomers use to measure the cosmos.