View looking south across the giant Janssen crater and Vallis Rheita.

The immense Janssen crater is an anomalous feature when roaming across the lunar disc looking for the next interesting target to image early in the waxing crescent lunar cycle (Day 5 when the sun angle is suitably low in this sector). At 185 km wide, Janssen is around 80% the size of Clavius. It occupies almost the entire top-right quadrant of this image! and has a very distinctive hexagonal shape (defined by the 6 white x's). My geological colleagues will know immediately what this means, given the lunar crust comprises largely of slow-cooled basalt. Mega-scale hexagonal shrinkage cracks in the cooling lunar proto-crust (also seen at small scale in columnar basalts on earth) set up hexagonal weak points in the lunar crust that allowed downward displacement of hexagonal blocks during large-scale impacts.

This old behemoth crater, Janssen, is deeply eroded and has been battered over the eons by younger impacts on the crater walls and floor. The most arresting of these is Fabricius (near the northern rim of Janssen) with its complex series of peaks rising from the central crater floor. The arcuate Rimae Janssen is also seen extending from the southern (top) end of Janssen and curving as it tracks northward to intersect the south rim of Fabricius. Other significant impacts in this field of view include Metius and Rheita plus the older degraded Brenner depression.

Rivalling Janssen, without doubt, is Vallis Rheita, the second longest valley (445 km long) on the near side of the moon. This valley reaches up to 30 km in width though it locally narrows to 10 km wide. Like Vallis Snellius, Vallis Rheita is also oriented radially to Mare Nectaris (though some link it to the Imbrium impact). This valley was gorged out of the lunar crust by linear chains of secondary impacts that occurred in rapid succession (in minutes) as material sprayed radially outward from the Nectaris impact, like spokes on a bicycle wheel. Trying throwing a cricket ball into a bucket of flour and see what happens.
These immense lunar impacts scoured deep valleys that are oriented radially around the largest mare-forming impacts in Nectarian times, part of the Late Heavy Bombardment.

What caused this immense cratering and scouring of the lunar surface at this time, 3.8 to 3.9 billion years ago? Current planetary reconstructions for the early history of the solar system have the gas giant Jupiter changing orbital position relative to the sun, and in doing so creating havoc and slinging asteroids and small plantisemals in all directions.

Hense Vallis Rheita and the other large mare-forming impact features owe their origins to the king of the planets Jupiter, the great sculptor of the solar system and the literal creator and destroyer of worlds (an apt description for Jupiter in “The Planets” by A.Cohen and B.Cox).
Skywatcher 8 inch/f5 Newtonian.