Contact binary moons?

Asteroids and comets formed as contact binaries were a real surprise to astronomy and geology theory. Now contact binary moons? Astronomers are suggesting that the small moon of Kuiper Belt planet MU69 may have somehow been formed through collision and melting fusing together of larger space bodies.

Earth-based observations suggest the small icy world, referred to simply as MU69, has a moonlet. It seems New Horizons will now be making a two-for-the price-of-one flyby when it has its encounter on New Year’s Eve and New Year’s Day, 2019.

... What emerged from the studies was fascinating. Not only does it seem there is an accompanying moonlet perhaps 200-300km from MU69, but the main target itself may also actually be a double act - either two individual units with a small gap between them; or just touching, something called a contact binary. "This is very exciting. This is going to have a lot of surprises,"
Nasa's New Horizons probe strikes distant gold | BBC

Will it be a binary moon, binary contact moon or a potato (rubber duck) shaped moonlet?

contact binary moon binaries asteroid comet

Are contact binaries the result of puzzling processes or plasma geology?

MU69

Kuiper Belt electric geology with craters and rilles, ridges etc? What will NASA's New Horizon mission observe?

"Using New Horizons' suite of seven instruments, we'll be characterising the geology and morphology of the surface, looking to see whether there are any craters. We certainly expect to see craters," explained team member Dr Anne Verbiscer from the University of Virginia. "Possibly there could be grooves. We'll also map the surface composition, searching for possible ices as we saw on Pluto.

"We also want to know what makes MU69 so dark and red. And we'll be searching for satellites and rings and asking if that moon is really there; and are there any others?"
Nasa's New Horizons probe strikes distant gold | BBC