SUNSET SKY SHOW: Mark your calendar. On June 15th and 16th, the crescent Moon will pass by Venus in the sunset sky, forming a beautiful conjunction in the constellation Cancer. Try to catch them before the twilight fades to black. When framed by cobalt blue, Venus and the Moon are extra beautiful. Sky maps: June 15, 16. And a bonus... MARS OUTSHINES SIRIUS: Mars is approaching Earth for an almost once-in-a-generation close encounter in late July. This week, the brightness of Mars surpassed that of Sirius, making the Red Planet brighter than any star in the sky. If you wake up before dawn, you can't help noticing Mars burning through the morning twilight with a distinctive orange glow--and the show is about to get much better, indeed.