Pluto may have a polar ice cap. This is the tantalising prospect revealed in the latest images to come down from the New Horizons spacecraft. The US space agency probe is en route to the dwarf planet and is set to make a close flyby on 14 July. Pictures taken from a distance of just over 100 million km display regions of varying brightness.
But it is a persistent light patch that catches the eye, which scientists say could be nitrogen ice on the surface. The diminutive world remains blob-like in the images, even though it is being seen through New Horizons’ powerful Lorri telescope.
Nonetheless, this is the best ever view we have had of Pluto, says mission principal investigator Alan Stern from the Southwest Research Institute. "These images are just a little bit better than anything that has ever been obtained in history," he told reporters.
"We on the New Horizons team feel a little bit like ocean mariners, explorers crossing between continents – weeks and weeks on the ocean in their case, nine-and-a-half years in our case. We can finally see the shore. That’s land ho! And the images are only going to get better and better from hereon out."
New Horizons was launched from Earth in 2006. Since then, it has crossed some 5 billion km of space. It is travelling so fast that it will not actually be able to get into orbit around Pluto when it arrives, and will have to grab as much data as possible as it barrels past the 2,300km-wide dwarf and its moons.