Mars rises around 1 a.m. local daylight time and climbs nearly 25° high in the south-southeast by the time twilight commences. The magnitude –0.7 Red Planet stands out against the backdrop of far eastern Sagittarius. If you point binoculars or a telescope toward the ruddy world this morning, you’ll see the magnitude 8.5 globular star cluster M75 just 0.3° to its north. A telescope also allows you to see some subtle surface features on the planet’s 13″-diameter disk.
Tuesday, May 15
Jupiter reached opposition and peak visibility just one week ago, and it remains a stunning sight all night. It appears low in the southeast during evening twilight and climbs highest in the south shortly after midnight local daylight time. Shining at magnitude –2.5, the giant planet is the night’s brightest celestial object once Venus sets around 10:30 p.m. Jupiter resides among the background stars of Libra the Scales, 2° east of Zubenelgenubi (Alpha [α] Librae). When viewed through a telescope, the gas giant’s disk spans 45″ and shows incredible detail in its cloud tops.
New Moon occurs at 7:48 a.m. EDT. At its New phase, the Moon crosses the sky with the Sun and so remains hidden in our star’s glare.
Saturn rises shortly after 11:30 p.m. local daylight time and climbs some 30° high in the south as morning twilight starts to paint the sky. The ringed planet shines at magnitude 0.3 against the backdrop of northern Sagittarius the Archer. When viewed through a telescope, Saturn shows an 18″-diameter disk surrounded by a stunning ring system that spans 41″ and tilts 26° to our line of sight.
Thursday, May 17
A wafer-thin crescent Moon appears 6° to the left of Venus this evening. Our satellite appears only 9 percent lit because it passed between the Sun and Earth just two days ago. You should notice an ashen light faintly illuminating the Moon’s dark side. This is earthshine — sunlight reflected by Earth that reaches the Moon and then reflects back to our waiting eyes. Use binoculars for the best view.
The Moon also reaches perigee, the closest point in its orbit around Earth, today. At 5:05 p.m. EDT, the Moon lies 226,040 miles (363,776 kilometers) away from us.