Seeing the Universe

before 1610 - naked eye astronomy

1608 - Galileo's hand held telescopes

1673 - Hevelius' long telescopes

1780 - Herschel's large reflectors

1838 - Meridian Circles

1845 - Rosse's Leviathian

1890 - Barnard's camera

1923 - The Hooker 100 inch

1948 - The Palomar 200 inch

1998 - The Keck 10 metre pair

2000 - The VLT array

2015 - Planning for the JWST

2020? - Planning the OWL

How much further?

The Hubble Space Telescope, was placed in low Earth orbit from a Space Shuttle in 1990. In its first decade of operation, the HST sent back clearer and further views of the universe than ever before obtained. Its position above the distorting and filtering effects of the atmosphere more than compensates for its relatively small mirror - only 2.5 metres in diameter, much smaller than the largest ground based scopes. Its high resolution camera recorded detail on the surface of Pluto. It peered for one hundred hours into each of two pin-head sized regions of the sky to obtain deep fields that establish the universe contains more than 50 billion galaxies. Its infrared camera pierced deep inside thick dust clouds to heart of stellar nurseries, and resolved newly forming solar systems.

The HST was designed to be upgraded. Space Shuttle Astronauts in three service missions have already replaced its cameras, solar panels, gyroscopes, computers and data recorders with improved versions. The image shows the telescope being released back into orbit from the Shuttle after one of those missions.  STScI: About the HST