Explanation:
Why does this large crater on Mercury have two rings and a smooth floor?
No one is sure.
The unusual feature called
Vivaldi Crater spans 215 kilometers and was imaged again in
great detail by
ESA’s and
JAXA’s
robotic
BepiColombo spacecraft on a
flyby earlier this month.
A large circular feature on a rocky planet or moon is usually caused by either an
impact by a small asteroid or a comet fragment, or a
volcanic eruption.
In the
case of
Vivaldi,
it is possible that
both occurred — a heavy strike that caused a smooth internal lava flow.
Double-ringed craters are rare,
and the cause of the inner rings remains a topic of research.
The speed-slowing
gravity-assisted
flyby of
Mercury by
BepiColombo was in preparation for the
spacecraft entering orbit around the
Solar System’s
innermost planet
in 2026.
Source: https://apod.nasa.gov/apod/ap240916.html
