Washington: NASA's New Horizons spacecraft has delivered stunning images of Pluto’s tiny moon Kerberos to the Earth this week, completing the family portrait of the icy dwarf planet's moons.
According to NASA, Kerberos appears to be smaller than scientists expected and has a highly-reflective surface, counter to predictions prior to the Pluto flyby in July.
“Once again, the Pluto system has surprised us,” said New Horizons Project Scientist Hal Weaver, said in a statement.
An image of Kerberos was created by combining four individual Long Range Reconnaissance Imager (LORRI) pictures taken on July 14, approximately seven hours before New Horizons’ closest approach to Pluto.
The new data was downlinked from the New Horizons spacecraft on October 20. It shows that Kerberos appears to have a double-lobed shape, with the larger lobe approximately 5 miles (8 kilometers) across and the smaller lobe approximately 3 miles (5 kilometers) across.
Science team members speculate from its unusual shape that Kerberos could have been formed by the merger of two smaller objects.
The reflectivity of Kerberos’ surface is similar to that of Pluto’s other small moons (approximately 50 percent) and strongly suggests Kerberos, like the others, is coated with relatively clean water ice.
Earlier, scientists theorised that Kerberos was relatively large and massive, appearing faint only because its surface was covered in dark material.
But the small, bright-surfaced Kerberos--now revealed in these new images--shows that the idea was incorrect, for reasons that are not yet understood.
“Our predictions were nearly spot-on for the other small moons, but not for Kerberos,” added New Horizons co-investigator Mark Showalter.
The new results are expected to lead to a better understanding of Pluto’s fascinating satellite system.
New Horizons is the first mission to the Pluto system and the mysterious Kuiper Belt - a relic of solar system formation.