Hubble Space Telescope 1946: U.S. astrophysicist Lyman Spitzer (above) publishes first paper about space telescopes Jul 1958: U.S. National Aeronautics and Space Act passed by Congress, creating NASA Oct 1977: Congress approves funding for Large Space Telescope 1978: Grinding of 2.4-metre primary mirror begins Secondary mirror Primary mirror Gyros (six) Astronaut to scale 1979: Astronauts begin training for servicing missions 1983: Large Space Telescope renamed in honour of astronomer Edwin Hubble (inset) Apr 24, 1990: Space shuttle Discovery launches Hubble Space Telescope SN 1997ff Jun: Spherical aberration in primary mirror detected – fault prevents Hubble from focusing sharply 1991: From remnants of Supernova 1987A (above), Hubble determines distance to Large Magellanic Cloud – a dwarf galaxy close to our Milky Way – within 5% accuracy, at 169,000 light-years 1992: Hubble detects disc of material being pulled into suspected black hole at core of galaxy NGC 4261 (below), 45 million light-years from Earth. Previously black holes were theoretical 1993: Astronomers use Hubble to determine age of universe – currently estimated at 13.8 billion years Dec: First servicing mission Jan 1994: NASA announces spherical aberration in Hubble’s mirror is corrected May: Hubble’s Faint Object Camera observes whirlpool of hot, ionized gas orbiting heart of Galaxy Messier 87 (M87 for short), at speed of about 550km per second. Data confirms existence of supermassive black holes Feb 1995: Hubble detects oxygen in atmosphere of Jupiter’s moon Europa Nov 1995: Star birth is seen in Hubble’s iconic Pillars of Creation (above) of towering columns of gas and dust in Eagle Nebula (M16). Located in constellation Serpens, M16 covers an area of 70 by 55 light-years 1996: Hubble reveals surface of dwarf planet Pluto (above) Feb 1997: Second servicing mission Sep 1998: Astronomers using Hubble publish first evidence that expansion of universe is not slowing down due to gravity as expected, but accelerating. Hubble’s observation of exploding supernova SN 1997ff, located about 10 billion light-years away, provides evidence that dark energy, which makes up 75% of universe, is driving expansion Nov-Dec 1999: Hubble enters safe mode after failure of fourth of six gyroscopes. Third servicing mission installs new computer and gyros May 2000: Astronomers use Hubble to discover vast quantities of missing hydrogen created in first few minutes of universe’s birth in Big Bang Mar 2002: Fourth servicing mission installs Advanced Camera for Surveys Aug 2006: Astronomers release direct proof of dark matter in galaxy cluster 1E 0657-56, also known as Bullet Cluster, about 3.8 billion light-years from Earth May 2014: Jupiter’s Great Red Spot is found to be shrinking Apr 2018: Hubble reveals furthest star ever seen. Light from Icarus takes nine billion years to reach Earth Mar 2022: Hubble detects light of star that has taken 12.9 billion years to reach Earth 1995 2014 Source: ESA, NASA, Space.com © GRAPHIC NEWS Pictures: Getty Images, ESA, NASA, Walter Jaffe (Leiden Observatory), Jeff Hester (Arizona State University), Alan Stern (SWRI), Marc Buie (Lowell Observatory), Adam Riess (Space Telescope Science Institute)