Article Posted on : - Mar 20, 2013

This file photo provided and annotated by NASA/Hubble Space Telescope shows the five moons in their orbits around Pluto.

NEW YORK (PTI): Pluto's orbit may host a formation of 10 or more tiny undiscovered moons, which would each measure just 1 to 3 kilometres across, astronomers say.

This preliminary finding could make life even more difficult for the team planning NASA's New Horizons mission, which is slated to take the first-ever up-close look at the Pluto system in July 2015.

After Pluto's fifth known moon, a small satellite known as P5, was discovered last year, officials said they may need to redraw the spacecraft's path to avoid such obstacles.

In the new study, astronomers led by Scott Kenyon of the Harvard-Smithsonian Centre for Astrophysics used computer simulations that treat smaller particles statistically, SPACE.com reported.

Once objects get above a certain size, roughly 1 km across, then the programme renders them individually - and this is when the satellites pop up.

It's hard to say how many there are, the researchers said, as it's difficult to simulate collisions among these tiny satellites. There could be anywhere from one to more than 10 objects lurking beyond Hydra's orbit.

While the team can simulate these satellites, they said it's unlikely they could be spotted, if they exist, from Earth.

The brightness of the potential objects dance with the edge of the Hubble Space Telescope's capabilities, Mr. Kenyon said, and they are likely beyond the reach of even the most sensitive ground-based telescopes, such as the Keck Observatory in Hawaii.

New Horizons might be able to spot smaller satellites before it gets there, but Mr. Kenyon said he wasn't sure when the objects would appear big enough for the spacecraft to detect.

The satellites would be 'easily visible' during the spacecraft's closest approach to Pluto in 2015, researchers said.

The study was submitted for publication in The Astronomical Journal.