This image was made over ten days in December 1995 using the Hubble Space Telescope. Image: R. Williams (STScI), the Hubble Deep Field Team and NASA

In the April 1990 edition of Physics Today, the astrophysicist C. Robert O’Dell wrote as follows about the Hubble Space Telescope that was launched that same month: “No other astronomy project has taken so long to develop, proven so technologically challenging or cost so much”. Three decades later, Physics Today sums up its impact thus: “Hubble has changed the way both astronomers and the general public understand the cosmos”. The editors then show a selection of the most important images sent back by the telescope, including the “Hubble Deep Field” of 1995. This photograph of distant galaxies has helped us acquire far more knowledge about the early development of the Universe.