NASA's New Horizons Clicks Pluto's Camera-Shy Moons 'Kerberos' and 'Styx'

As NASA's New Horizons space probe nears Pluto, it has sighted the smallest and faintest of the planet's moons.

Images taken by the spacecraft's Long Reconnaissance Imager between April 25 and May 1 showed Kerberos and Styx along with three other moons Charon, Hydra and Nix. New Horizons is around 90 million miles away from Pluto.

"Detecting these tiny moons from a distance of more than 55 million miles is amazing, and a credit to the team that built our LORRI long-range camera and John Spencer's team of moon and ring hunters," said New Horizons Principal Investigator Alan Stern.

From the imaging data, researchers estimate that Styx is just about 7 to 21 kilometers in diameter and orbits Pluto in 20 days while Kerberos measures 10 to 30 kilometers in diameter with a 32-day orbit period. The images sent by the spacecraft were processed to view the smaller moons as their faintness makes them difficult to spot amidst the brightness of Pluto and its biggest moon Charon.

New Horizons is on the watch for additional satellites and other heavenly bodies that would obstruct its transit through Pluto's vicinity.

"New Horizons is now on the threshold of discovery. If the spacecraft observes any additional moons as we get closer to Pluto, they will be worlds that no one has seen before," said mission's team member John Spencer.