Title: April Skywatch Highlights
Location: Hawaiian Islands
Date / Time: April 2012
Comments: You might want to choose JUPITER, as your first target of the evening. In early April, Jupiter shines brilliantly at magnitude minus-2.1, about 15 degrees above the western horizon, one hour after sunset. Jupiter, currently in Aries, appears lower in the western sky with each passing night and, by April 15th, the gas giant lies only 5 degrees above the western horizon at sunset. On April 22nd, look for a slim crescent Moon just a few degrees above the planet in the bright twilight. Jupiter disappears from view by the end of the month. Stunning VENUS continues to bedazzle us this month. At magnitude minus -4.5, Earth's planetary "neighbor" shines far brighter than any other point of light in the sky. Venus shimmers high in the west after sunset. It reached eastern elongation (its greatest angular distance east of the Sun) in late March. Venus will be visible until 10PM throughout April, as it traverses eastward across Taurus, the Bull. MARS is high in the East at sunset, dominating the background stars of its host constellation, Leo, the Lion. On April 15th, Mars appears within 4 deg. of Regulus and, at magnitude minus -0.4, the Red Planet easily outshines Leo's brightest star. Notice the color contrast between orange-red Mars & blue-white Regulus. A telescopic view reveals Mars' north polar ice cap, and more subtle features, which show up as contrasting shades of orange & brown. Mars will be viewable most of the night, setting after 3:30AM throughout the month. SATURN reaches opposition and peak visibility this month. The ringed planet lies opposite the Sun in our sky on the 15th, which means it rises at sunset & will be visible until sunrise. Saturn lies at its closest to Earth at opposition & so appears brightest; peaking at magnitude 0.2. Saturn appears in the constellation Virgo, the Maiden, just 5 degrees NE of Spica, Virgo's brightest star. Notice Saturn's golden hue, compared to blue-white Spica. Saturn's rings open wider than they've been since 2007, tilting at 14 degrees to our line of sight from Earth, & affording impressive views through even a small telescope. You might be able see the Cassini Division, a dark gap that separates the outer A ring from the broader & brighter B ring. Small telescopes also reveal some of Saturn's moons, including 8th magnitude Titan, the biggest & brightest. MERCURY reaches greatest elongation April 18, when it lies 27 degrees west of the Sun. The tiny innermost planet shines brightly at magnitude 0.3, however it's somewhat difficult to spot in the Spring morning sky. During the 2nd & 3rd week of April, look for Mercury in the eastern sky before sunrise (around 5AM), very low on the horizon. Just before sunrise on April 18th, look for Mercury 8 degrees south of the Moon. The Southern Cross, (Crux), rises high enough for viewing by 11:30 PM at the start of April, and by 10 PM at months end. To view Crux, you'll need an unobstructed view to the southern horizon. About an hour after Crux rises, look for 2 bright stars, Alpha & Beta Centauri, which "point" to the Cross to their right/west. At this time of evening, you should be able to see all the way from Polaris, (the North Star), to the bottom star in the Southern Cross, Acrux. For an April Hawaiian sky map visit Bishop Museum Planetarium www.bishopmuseum.org/planetarium (bishopmuseum.org)

Maintained by Roz Reiner - Kauai, Hawaii

 

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