The brilliant tracers pouring from the centre of this image may have a dainty, colourful appearance. Their origins are anything but peaceful, however. These are rolling cauldrons of gas, heated to more than 20,000C, and they are pouring from a dying star five times bigger than our own Sun. The star – which lies within our own galaxy, the Milky Way – has blasted off its outer envelope of gases and is now unleashing a stream of ultraviolet radiation that is causing those gases to glow.
This is astronomical object NGC 6302, although it is better known, simply, as the Butterfly Nebula. Its image was captured recently by the Hubble space telescope, which was launched by the space shuttle 20 years ago, on 24 April 1990.
Although hampered by a lens that had been ground to the wrong shape, the telescope – named after US astronomer Edwin Hubble (1889–1953) – has proved to be one of the most spectacularly successful spacecraft ever built by Nasa. It was repaired in 1993 and thanks to a further four service missions the Hubble has gone on to generate thousands of images of the heavens, ranging from pictures of the universe's remotest galaxies to photographs of planets inside the solar system. These are the mostly widely used and most popular images produced by any space agency.
When Nasa announced it would no longer service the Hubble following the destruction of the shuttle Columbia in 2003, there was a public outcry in the United States. Nasa was forced to reinstate the mission which took place in May 2009 and which is expected to keep the Hubble operational until 2014 when it will replaced by another orbiting telescope, the James Webb.
By that time, the Hubble – which orbits 350 miles above the Earth – will have produced breathtaking photographs of space for almost a quarter of a century, captivating the public while also playing a crucial role in providing astronomers with precise measurements of the heavens.
Indeed, its studies of galaxies billions of light years away have generated a wealth of scientific papers and provided a new window on the early universe as well as a fresh understanding of its age and rate of expansion. We now know the universe is 13.75 billion years old while the Hubble has also revealed that its expansion, far from slowing down as had been expected, is in fact accelerating due to the influence of a mysterious force known simply as dark energy.
It is intriguing stuff. Nevertheless, it will be its collection of breathtaking photographs, such as this image of the Butterfly Nebula, that will be the telescope's enduring legacy.
• This article was amended on 12 April 2010. The original referred to the Hubble telescope launch date as April 1980. This has been corrected.