NASA probe beams sharpest ever images of Pluto

NASA's New Horizons spacecraft has sent back some of the sharpest images of Pluto, showing a wide variety of cratered, mountainous and glacial terrains, which may be the best close-ups of the icy-dwarf planet that humans could see for decades.

Each week the piano-sized New Horizons spacecraft transmits data stored on its digital recorders from its flight through the Pluto system on July 14 this year.

These latest pictures are part of a sequence taken near New Horizons' closest approach to Pluto, with resolutions of about 77-85 metres per pixel - showing features less than half the size of a city block on Pluto's diverse surface.

In these new images, New Horizons captured a wide variety of cratered, mountainous and glacial terrains.

"These close-up images, showing the diversity of terrain on Pluto, demonstrate the power of our robotic planetary explorers to return intriguing data to scientists back here on planet Earth," said John Grunsfeld, former astronaut and associate administrator for NASA's Science Mission Directorate.

"New Horizons thrilled us during the July flyby with the first close images of Pluto, and as the spacecraft transmits the treasure trove of images in its onboard memory back to us, we continue to be amazed by what we see," Grunsfeld said.

These latest images form a strip 80 kilometres wide on a world 4.8 billion km away.

Pluto. Photo: NASA

The pictures trend from Pluto's jagged horizon about 800 kilometres northwest of the informally named Sputnik Planum, across the al-Idrisi mountains, over the shoreline of Sputnik, and across its icy plains.

"These new images give us a breathtaking, super-high resolution window into Pluto's geology," said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI) in Colorado.

"Nothing of this quality was available for Venus or Mars until decades after their first flybys; yet at Pluto we're there already - down among the craters, mountains and ice fields - less than five months after flyby," said Stern.

The images were captured with the telescopic Long Range Reconnaissance Imager (LORRI) aboard New Horizons, about 15 minutes before New Horizons' closest approach to Pluto - from a range of just 17,000 kilometres.

They were obtained with an unusual observing mode; instead of working in the usual "point and shoot," LORRI snapped pictures every three seconds while the Ralph/Multispectral Visual Imaging Camera (MVIC) aboard New Horizons was scanning the surface. This mode requires unusually short exposures to avoid blurring the images.

Pluto. Photo: NASA

These new images are six times better than the resolution of the global Pluto map New Horizons obtained, and five times better than the best images of Pluto's cousin Triton, Neptune's large moon, obtained by Voyager 2 in 1989.

Mission scientists expect more imagery from this set over the next several days, showing even more terrain at this highest resolution.