Astronomers use many methods to determine this number, including gravitational lensing, the universe’s expansion rate, and more.

John Dobson, born in 1915, relocated to San Francisco from Beijing in 1927. Following a period as a monk within the Ramakrishna Order (1944-1967), Dobson cultivated a passion for astronomy. He is ...

Mars and Spica will appear in close proximity (2° separation) in the evening western sky shortly after sunset, setting before 9 PM local daylight time. Observations of Mars and Spica are best ...

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