A crescent Moon will rise shortly before planet Mars in the early-morning sky on May 14. Look for earthshine lighting up the darkened portions of our satellite, as in this photo captured in November 2015. Credit: Natalio (Flickr, CC BY-NC-ND 2.0) Sky This Week is brought to you in part by Celestron. Friday, May 8 Pluto is stationary at 7 A.M. EDT in Capricornus, although the nearby Moon ensures it’s not a great day for tracking down the faint dwarf planet.  Instead, take some time to enjoy the last of the winter constellations, now sinking quickly toward the western horizon after dark. Sirius, the brightest star in the sky and the alpha star of Canis Major, is now just 7° high in the west an hour after sunset. This low, it may be subject to some intense scintillation, causing it to shift in brightness and even color quickly as you watch.…