The uncertainty of science: The New Horizons science team has released their best image of Pluto’s moon Kerberos, finding it to be nothing like what they expected.
Before the New Horizons encounter with Pluto, researchers had used Hubble Space Telescope images to “weigh” Kerberos by measuring its gravitational influence on its neighboring moons. That influence was surprisingly strong, considering how faint Kerberos was. They theorized 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 by these new images show that that idea was incorrect, for reasons that are not yet understood.
Instead, Kerberos is much smaller than expected, and its surface is bright, suggesting it is covered by relatively clean ice. It is also double lobed, kind of like Comet 67P/C-G.