2019 June 15
Stereo Helene
Image Credit:
Cassini Imaging Team,
ISS,
JPL,
ESA,
NASA;
Stereo Image by
Roberto Beltramini
Explanation:
Get out your
red/blue glasses and float next to Helene,
small, icy moon of Saturn.
Appropriately named, Helene
is one of four known Trojan moons, so called because it orbits at a
Lagrange
point.
A Lagrange point is a gravitationally stable position
near two massive bodies, in this case
Saturn
and larger moon Dione.
In fact, irregularly shaped ( about 36 by 32 by 30 kilometers)
Helene orbits at Dione's leading Lagrange point while
brotherly ice moon Polydeuces follows at Dione's trailing Lagrange
point.
The sharp stereo
anaglyph was constructed from two
Cassini images captured during
a
close flyby in 2011.
It shows part of the Saturn-facing hemisphere of Helene
mottled with craters and gully-like features.