f556c24b__04_22_2004____Background_Info__2004
[1990] Refine the estimates for the age of the universe. Estimates ranged from 10 to 20 billion years. [2004] 
Reduced the uncertainty of the universe's age to 10 percent by calculating the distances to nearby galaxies. Another Hubble observation independently confirmed the universe's age by finding the faintest white dwarfs in our Milky Way galaxy, which act as cosmic clocks.
HubbleSite - NewsCenter - The Lure of the Rings (04/22/2004) - Background Info
2004