The evening sky presents quite a show this month. The bright planets Venus and Jupiter shine prominently in the northwest as the sky darkens. It’s best to look for Venus first. The brilliant planet shines at magnitude –3.9 but still lies in twilight. Fortunately, the inner world continues to move away from the Sun and thus appears slightly higher in the sky with each passing day. It makes a fine sight below Orion the Hunter at the start of the month. As the planet slides eastward relative to the background stars during May, it reaches Gemini the Twins and approaches Jupiter by month’s end. On the 31st, a telescope reveals Venus’ 13″-diameter disk and 80-percent-lit phase. Look higher in the sky and you’ll easily see magnitude –1.9 Jupiter . The giant planet also moves eastward relative to the starry backdrop, but at a much slower pace than Venus. This brings it closer to the horizon from one week to the next.…