PS: Helene has two faces
Posted: Thu Mar 11, 2010 8:27 pm
Helene has two faces
Planetary Society - 2010 March 11
Cassini's views of Helene through March 2010
Ian Regan composed this montage of Cassini's highest resolution views of Dione's co-orbital moon Helene
to attempt to make sense of the positions of its features. The small moon appears very different seen
from different angles and under different lighting conditions. (NASA / JPL / SSI / Ian Regan)
Planetary Society - 2010 March 11
Emily Lakdawalla wrote:Helene is two-faced; it has two very different hemispheres. The Saturn-facing hemisphere is peppered with small impacts, little craters one to a few kilometers across (Helene is a little more than 30 kilometers in diameter). But the anti-Saturn hemisphere doesn't have that peppering of craters; there are a few, much larger craters closer to 10 kilometers across.
Why does Helene have this dichotomy? I haven't the slightest idea. The ring system is Saturnward of Helene, so maybe that peppering of impacts has something to do with the rings; I don't know. But with the benefit of this helpful montage, I can observe that that dichotomy exists, and ask for an explanation!
Cassini's views of Helene through March 2010
Ian Regan composed this montage of Cassini's highest resolution views of Dione's co-orbital moon Helene
to attempt to make sense of the positions of its features. The small moon appears very different seen
from different angles and under different lighting conditions. (NASA / JPL / SSI / Ian Regan)