The solar system’s two biggest planets, Jupiter and Saturn, are well placed for viewing in April. Venus and Mars are lost in the light of the sun all month, and Mercury puts in a typically fleeting appearance.
Jupiter remains the brightest dot in our April evening sky. At the start of April, the planet is still visible for most of the evening. Jupiter is about halfway up in the west at dusk (around 7:15 p.m.) on Monday and sets by 11 p.m. By the end of April, Jupiter is only one-third of the way up in the west at dusk and sets by 9:30 p.m., giving us only a couple of hours to catch the king of the planets.
Jupiter remains in Taurus the Bull throughout April. Throughout the month Jupiter appears more and more distant from the bright star Aldebaran in Taurus. Aldebaran is slightly reddish-orange, and Jupiter is a brilliant white.
Look for the waxing crescent moon below Jupiter on April 13, and just above Jupiter on April 14.
Saturn rises in the east throughout April as Jupiter sets in the west, as seen on our April star map. In early April, Saturn rises just before 9 p.m. and is about one-third of the way up in the west at dawn. By the end of the month, Saturn will already be about 10 degrees above the east horizon at dusk, will be high in the south at midnight, and will set at dawn in the east.
Throughout the month, Saturn forms a triangle with two bright stars, one slightly brighter than Saturn and one slightly dimmer. The brighter star is Arcturus (slightly orange-yellow), about 30 degrees, or three palms, above Saturn. The slightly dimmer star is Spica (slightly blue), to the right of Saturn by about 15 degrees, On the night of April 24-25, the full moon will be right in between Saturn and Spica.
Saturn is in opposition on the night of April 28, meaning the sun is on the exact opposite side of the Earth. Saturn comes up at sunset, is high overhead at midnight and sets at dawn. During opposition Saturn is closer than usual to Earth, though it is still 819 million miles away.
For the first half of April Mercury rises in the east just after 5 a.m. and is about 8 degrees above the horizon at daybreak. Look for the very thick waning crescent moon to the left of Mercury at dawn on April 8. After mid-April we lose Mercury in the light of the sun.
Lyrid shower
The Lyrid Shower, the first significant meteor shower since the January Quadrantids, peaks on the night of April 21-22. That is, stay up late on April 21, past midnight, and look for shooting stars.
The shower is active from April 16 to 25. While not one of the strongest showers, the Lyrids can produce up to 20 meteors per hour. This year, the waxing gibbous moon provides interference until the moon sets early on April 22.
The moon goes down at 3:45 a.m. on April 22, so your best bet might be to get up early and try to catch the shower from 3:45 a.m. to dawn on April 22. The Lyrids come from the debris of Comet C/1861 G Thatcher.
Space station pass
On Thursday evening, there should be a spectacular pass of the International Space Station as seen from the Hawaiian islands. The space station will shine several times brighter than even Jupiter, the brightest regular dot in our current night sky.
The station will rise almost exactly southwest at 8:06 p.m. At about 8:10 p.m. it will pass between Sirius, the brightest star (on the station’s left), and Orion (on the station’s right). The space station will continue high up toward the bright stars in Gemini before fading away at 8:11 p.m. Given that this pass occurs in full darkness, rises high in the sky, passes some of the most brilliant stars in the sky and rises quite high, this should be a really great appearance of the space station.
As always, please check online on the day of the pass to make sure the timing has not changed. Visit heavens-above.com.
When you open this home page, 1) go to configuration and select "database"; 2) select "Honolulu" (the one in Hawaii, not North Carolina); select "ISS" ("International Space Station") and it will give you all appearances for the next 10 days.
April Sky Map
This map is good for 11 p.m. in early April and 9 p.m. at the end of the month. April of each year is usually the best time to catch all of the famous constellations in the sky at one time.
Most of the great winter constellations are still just barely visible low in the west, including Orion, Canis Major, Auriga and Gemini.
High in the north, the Big Dipper is a handy guide to locate both the North Star (by using the pointer stars, the two stars in the cup that don’t have the handle attached) and Arcturus. The handle of the Big Dipper points to Arcturus, which is rising in the east in this map. Arcturus is known in Hawaiian as Hokulea. Arcturus is the brightest star in Bootes the herdsman. Below Bootes, the Corona Borealis is rising, and below it Hercules.
Leo the Lion, the classic spring constellation and the first of Hercules’ 12 labors, is in the center of our April sky. Below Leo is the second labor of Hercules, the snaky constellation on Hydra.
Continuing down to the south horizon, look for the Southern Cross (Crux) rising in the south.