Iconic Hubble celebrates 20 years of space discoveries

ASTRONOMERS around the world this weekend marked the 20th anniversary of the launching of the iconic Hubble, NASA’s first orbiting space telescope that has revolutionised human understanding of the universe.

More than any other instrument, the Hubble has stimulated a modern-day infatuation with deep space, beaming to Earth the most spectacular images ever taken of faraway galaxies and the births and deaths of stars – and along the way helping scientists make some of the most important discoveries of our time.

Hubble was launched aboard space shuttle Discovery on April 24, 1990 and deployed into orbit the following day.

Piloting the shuttle on that historic mission was astronaut Charles Bolden, who went on to become the US space agency’s administrator last year.

In the two decades since, Hubble has enabled astronomers to peer through the celestial curtain to set the age of the universe at 13.7 billion years old.

“Hubble is undoubtedly one of the most recognised and successful scientific projects in history,” said Ed Weiler, associate administrator for NASA’s Science Mission Directorate.

From its unique perch some 570 kilometres above Earth, the telescope is our eye on the cosmos, snapping pictures of more than 30,000 celestial objects, some of them located on the far ends of the universe.

The quality of Hubble images is 10 times clearer than pictures from the most powerful ground-based telescopes, because it is beyond the Earth’s atmosphere, which distorts the view of ground telescopes.

“It’s that extreme clarity that gives us the feeling we’ve travelled out into space to see these objects,” said Jon Grunsfeld, an astronaut who did repair work on Hubble during two shuttle missions.

“It really is our time machine.”

When it became fully operational in late 1993 the Hubble began transmitting pictures that stunned the world.

One of Hubble’s best known images is of the vast Carina Nebula, an interstellar cloud of dust, hydrogen gas, helium gas and plasma that lies some 6,500 light years away from Earth. Each light year is about 9.5 trillion kilometres.

The Hubble also photographed supernovas, gigantic explosions that mark the death of a star. It revealed the existence of black holes at the centre of practically all galaxies.

Until then scientists only suspected the existence of black holes.