File:Out of the shadow – annotated ESA24939324.png

English: Mercury starts appearing from the night side at the top right of this image taken by the ESA/JAXA BepiColombo mission on 19 June 2023 as the spacecraft sped by for its third of three gravity assist manoeuvres at the planet.
The image was taken at 19:49 UTC (21:49 CEST) by the Mercury Transfer Module’s monitoring camera 3, when the spacecraft was about 2536 km from the planet’s surface. Closest approach took place at 19:34 UT (21:34 CEST) on the night side of the planet at about 236 km altitude. The back of the Mercury Planetary Orbiter’s high-gain antenna and part of the spacecraft’s body is also visible in front of Mercury in this image.
Despite the dark nature of the image, several interesting geological features are seen in beautiful detail. Of particular interest is Beagle Rupes, a 600 km-long scarp that snakes over the surface. In this view it is seen cutting through a distinctive elongated crater named Sveinsdóttir, which likely got its shape from an impactor striking the surface at an angle.
Beagle Rupes bounds a slab of Mercury’s crust that has been thrust westwards by at least 2 km over the adjacent terrain. The scarp curves back at each end more strongly than most other examples on Mercury. Geologists can use this geometry to estimate the thickness of the crustal slab (the thrust sheet) that has been displaced.
The volcanic-tectonic history of this entire region is not clearly understood, but scarps like this may have formed as a result of the planet cooling and its surface contracting, causing its surface to become wrinkled like a drying out apple. In addition, many nearby impact basins have been flooded by volcanic lavas, making this a fascinating region for follow-up studies by BepiColombo.
At the far right of the image the peak ringed impact crater Manley, just named ahead of BepiColombo’s flyby, is also visible. The 218 km-wide crater has a 120 km-wide circular peak-ring of material in its interior resulting from the formation process of the crater. The original basin floor, especially inside this ring, was subsequently flooded by lava that is responsible for the smooth interior texture.
The cameras provide black-and-white snapshots in 1024 x 1024 pixel resolution.
The image has been lightly processed to bring out the surface details of the planet.
Some imaging artefacts such as horizontal striping are also visible. Vignetting is visible in the top right corner. In this view, north is to the upper left corner.
The gravity assist manoeuvre was the third at Mercury and the sixth of nine flybys overall. During its seven-year cruise to the smallest and innermost planet of the Solar System, BepiColombo makes one flyby at Earth, two at Venus and six at Mercury to help steer it on course for Mercury orbit in 2025. The Mercury Transfer Module carries two science orbiters: ESA’s Mercury Planetary Orbiter and JAXA’s Mercury Magnetospheric Orbiter. They will operate from complementary orbits to study all aspects of mysterious Mercury from its core to surface processes, magnetic field and exosphere, to better understand the origin and evolution of a planet close to its parent star.
Click here for a non-annotated version of this image.
Read more