Template:Featurt airticle/September 2017
The Muin is an astronomical bouk that orbits planet Yird, bein Yird's anerly permanent naitural satellite. It is the fift-lairgest naitural satellite in the Solar Seestem, an the lairgest amang planetar satellites relative tae the size o the planet that it orbits (its primar). Follaein Jupiter's satellite Io, the Muin is seicond-densest satellite amang thae whase densities are kent.
The Muin is thocht tae hae formed aboot 4.51 billion years ago, nae lang efter Yird. The maist widely acceptit explanation is that the Muin formed frae the debris left ower efter a giant impact atween Yird an a Maurs-sized bouk cried Theia.
The Muin is in synchronous rotation wi Yird, ayeweys shawin the same face, wi its near side merked bi daurk volcanic maria that fill the spaces atween the bricht auncient crustal hielands an the prominent impact craters. As seen frae the Yird, it is the seicont-brichtest regularly veesible celestial object in Yird's sky, efter the Sun. Its surface is actually daurk, awtho compared tae the nicht sky it appears verra bricht, wi a reflectance juist slichtly heicher nor that o worn asphalt. Its gravitational influence produces the ocean tides, bouk tides, an the slicht lenthenin o the day.