The Sky This Week: April 11 – 18
Saturn and Mars rise before midnight, asteroid 6 Hebe lies with Leo the Lion, and the Winter Hexagon continues to dominate the night sky.
Monday, April 11
Although the calendar may say it is spring, the so-called Winter Hexagon remains prominent on April evenings. One of the sky’s largest asterisms — a recognizable pattern of stars separate from a constellation’s form — the hexagon stands out in the western sky after darkness falls. To trace this asterism, start with southern Orion’s luminary, Rigel. From there, the hexagon makes a clockwise loop. The second stop is brilliant Sirius in Canis Major. Next, pick up Procyon in the faint constellation Canis Minor, then the twins Castor and Pollux in Gemini, followed by Capella in Auriga, Aldebaran in Taurus, and finally back to Rigel. The waxing crescent Moon adds to the scene from its current perch within the hexagon.
Tuesday, April 12
Saturn rises just before midnight local daylight time this week and climbs highest in the south shortly before morning twilight starts to paint the sky. The ringed planet shines at magnitude 0.3 among the much fainter background stars of southern Ophiuchus. Any telescope will show you Saturn’s 18″-diameter disk surrounded by a spectacular ring system that spans 40″ and tilts 26° to our line of sight.
Wednesday, April 13
You can find the First Quarter Moon high in the southwest as darkness falls, then watch as it sinks toward the western horizon, where it sets shortly after 2 a.m. local daylight time. Our satellite officially reaches its First Quarter phase at 11:59 p.m. EDT. The half-lit Moon spends the night among the background stars of southern Gemini the Twins.
Thursday, April 14
Asteroid 6 Hebe currently lies among the background stars of eastern Leo the Lion, just a stone’s throw from 2nd-magnitude Denebola. This region rides high in the southeast during the early evening hours and peaks in the south around 11 p.m. local daylight time. This evening, 10th-magnitude Hebe lies some 2.5° due north of Denebola.
Friday, April 15
Although Jupiter reached opposition and peak visibility over a month ago (on March 8), it remains a stunning sight from dusk until the start of morning twilight. The giant planet shines at magnitude –2.4 against the backdrop of Leo the Lion. Turn a telescope on Jupiter and you will see a 43″-diameter disk with lots of atmospheric detail. And this evening, you also can observe the shadows of two of its large moons. Volcanic Io casts its shadow onto the jovian cloud tops starting at 6:55 p.m. EDT (unfortunately still during daylight), but the black dot doesn’t leave the disk until 9:10 p.m. If you miss Io, you don’t have to wait long for icy Europa’s shadow to show up. It traverses Jupiter from 9:32 p.m. until 12:18 a.m.
Saturday, April 16
Mars pokes above the eastern horizon just after 11 p.m. local daylight time this week and remains prominent until morning twilight is well underway. The Red Planet’s eastward motion relative to the background stars of southern Ophiuchus comes to a halt today; it then starts moving westward at the start of its so-called retrograde loop. This is a sure sign that Mars is approaching peak visibility, which it will reach at opposition in late May. Our neighboring world currently shines at magnitude–1.0, trailing only the Moon, Jupiter, and Sirius. When viewed through a telescope, Mars appears 14″ across and should display a prominent north polar cap as well as subtle dark markings.
Sunday, April 17
The waxing gibbous Moon’s motion through the night sky carries it near Jupiter tonight. The night sky’s two brightest objects appear only 2° apart, or about four times the Moon’s diameter.
Source
Witches Of The Craft® 