By Dr David Whitehouse BBC News Online science editor

The Hubble Space Telescope (HST) has its infrared vision back.

The orbiting observatory had been blind at infrared wavelengths since 1999 when Nicmos, or the Near Infrared Camera and Multi-Object Spectrometer, ran out of coolant.

It is fantastic that we have restored Hubble's infrared eyesight

Dr Rodger Thompson

However, in March astronauts refurbished Hubble and installed an advanced cooling system that will keep the key instrument operating indefinitely.

Astronomers have now released the first test images from the revived Nicmos, showing superbly its ability to penetrate deep into the layers of dust that obscure stars from the view of other instruments.

One of the images is a near-infrared view of the Cone Nebula, which Hubble exposed in all its glory in April with its new Advanced Camera for Surveys.

Turbulent region

After Nicmos was first installed on board Hubble in 1997, it made observations of newly forming stars, and regions containing the farthest and faintest galaxies ever imagined.

	The Nicmos can go where other instruments cannot

It revealed as never before planets in our Solar System and possible planets beyond. It has also observed a supernova that confirmed our Universe is expanding at an accelerating rate.

Nicmos achieved nearly all its scientific objectives before 1999, when the coolant necessary to chill its infrared detectors was depleted.

Following its refurbishment earlier this year, astronomers say the Nicmos is back to its best - and point to its observations of the Cone Nebula as justification.

The Cone Nebula seen by Nicmos: The instrument can see through the dust

The new image shows the tip of the nebula, about half a light-year long (the entire nebula is seven light-years in length). The Cone Nebula resides in a turbulent star-forming region, which is located 2,500 light-years away in the constellation Monoceros.

Over millions of years, radiation from hot, young stars located outside the Hubble image has slowly eroded the nebula. Ultraviolet light is heating the edges of the dark cloud, pushing gas into the relatively empty region of surrounding space.

Ring of stars

Nicmos has also peered into the dusty disc of the edge-on galaxy called NGC 4013 and seen all the way to its galactic core.

NGC 4013, which looks similar to our own Milky Way, resides in the constellation Ursa Major, 55 million light-years from Earth.

The Cone Nebula as seen by Hubble's ACS: The Nicmos image looks at the very top of the cloud

To the surprise of astronomers, Nicmos found a brilliant band-like structure, which may be a ring of newly formed stars also seen edge on.

The extremely bright star near the centre of the picture (top) is a nearby, foreground star belonging to our own Milky Way.

The ring-like structure spied by Nicmos encircles the core and is about 720 light-years wide, which is the typical size of most star-forming rings found in such disc-shaped galaxies.

The human eye cannot see infrared light, so colours have been assigned to correspond with near-infrared wavelengths.

The HST: Its refurbishment could not have gone better

The blue light represents shorter near-infrared wavelengths and the red light corresponds to longer wavelengths.

"It is fantastic that we have restored Hubble's infrared eyesight," said Dr Rodger Thompson, the Nicmos Principal Investigator, based at the University of Arizona, Tucson, US.

"Nicmos has taken us to the very fringes of the Universe and to a time when the first galaxies were formed. We can't wait to get back out there."