A Lame Lyrids Meteor Shower, Birds Fly Around the Full Egg Moon, and Some Sights to See in Moonlight!
The Moon and Planets
This week, the moon will continue to fill with light as it waxes from First Quarter to full before the coming Easter weekend. Tonight (Sunday), the moon will sit less than a palm’s width to the right of the bright, white star Regulus, which marks the heart of Leo (the Lion). See if you can find the backwards question mark of stars extending upwards from Regulus. Those five stars form the front end of the lion. The “hook” measures about 1.5 fist diameters, top to bottom.
Over the rest of the week, the moon will rise later each night and pass though the rest of Leo, and then Virgo (the Maiden) and Libra (the Scales). Friday morning brings the Full Egg Moon, so it will look full on both Thursday and Friday night. Next week, I’ll tell you why the moon dictates when Easter occurs, and why Easter 2019 is later than some might expect.
Also known as the Sprouting Grass Moon, Pink Moon, and Fish Moon, the April full moon always shines in or near the stars of Virgo, and is visible globally. When fully illuminated, the moon’s geology is enhanced, especially the contrast between the bright ancient cratered highlands and the dark, younger, smoother maria. This summer will mark the 50th anniversary of the first footsteps by humans on the moon.
The reddish planet Mars will continue to be easily spotted without optical aid for a couple of hours after dusk every evening this week. But the later spring sunsets mean that Mars will set in the west just before midnight local time this week. Once the sky has darkened, look for Mars as a medium-bright, reddish pinpoint of light sitting one-third of the way up the western sky. Mars has been slowly shrinking in size and brightness as we increase our distance from it little-by-little. If you aren’t sure exactly where Mars is, look for the bright, bluish Pleiades star cluster sitting a generous fist diameter to the planet’s lower right. Look for the star Aldebaran, which is brighter than Mars right now and has a similar reddish colour, sitting a palm’s width to the lower left of Mars all week.
Oops! Last week I indicated that Jupiter was rising before midnight. But that won’t begin happening in the GTA until the closing days of April. This week, the very bright planet will rise a little after 12:30 am local time. By 6 am, Jupiter will catch your eye in the lower part of the southern sky. Yellowish Saturn, the second brightest object in the southern pre-dawn sky, will be also visible before as dawn arrives. The ringed planet will be sitting about 2.5 outstretched fist diameters to the left of Jupiter.
Mercury and Venus can both be spotted low in the eastern sky just before sunrise this week. For some time now, very bright Venus has been descending and moving eastward towards the sun. This has also brought Venus within a few finger widths of Mercury, which can be found to Venus’ lower left. After mid-week, Mercury’s faster sunward orbit will move it farther from Venus. Due to Mercury’s position below a slanted morning ecliptic, this will be a very poor pre-dawn appearance of the swift planet for Northern Hemisphere skywatchers, but a very good one for those viewing Mercury from the Southern Hemisphere. In the GTA, your best time to see Mercury will fall between about 6 and 6:15 a.m. local time.
Uranus is too close to the evening sun for viewing. Neptune is still embedded in eastern pre-dawn twilight, but it will become observable in a few weeks.
Lyrids Meteor Shower
The annual Lyrids meteor shower, derived from particles dropped by comet C/1861 G1 (Thatcher), runs from April 16 to 25 every year and peaks before dawn on Monday, April 22, worldwide. This shower can produce up to 18 meteors per hour, with occasional fireballs. True Lyrids will appear to be travelling away from a point in space (the shower’s radiant) near the bright star Vega, which will be high in the eastern sky before dawn. Unfortunately, a bright, gibbous moon will wash out all but the brightest meteors this year.
You can start watching as soon as it’s dark. Even when the peak number occurs before dawn, meteors will still be visible before midnight, too. Don’t worry about looking directly at the radiant. Bring a blanket and a chaise to avoid neck strain. And remember that binoculars and telescopes will not help: their field of view is too narrow to see the long meteor trails. If you have friends or family along, don’t look at each other while chatting. Keep your eyes to the skies!
Bright Moonlight Targets
Generally speaking, once the moon becomes more than 50% illuminated, its bright moonlight hinders the viewing of everything but the brightest stars and planets. Nevertheless, there are always interesting sights to see. Here are some things to entice you out under the stars this week — if you aren’t a moon fan.
While commonly thought of as twin stars, Castor and Pollux are visually different under closer inspection. In mid-evening they are positioned halfway up the western sky. Castor, the more westerly star, is a hot white A-class star located 51 light-years from Earth and shining at magnitude 1.9. In a backyard telescope, Castor resolves into a nice double star, although it is actually six stars made up of three binary pairs. Pollux is a cooler, yellow G-class (like our sun) star situated 34 light-years away. Its more golden hue can be seen visually. At this time of year, the pair of stars sets after 3 am local time.
The evening eastern sky on mid-April evenings is dominated by the bright orange star Arcturus, aka Alpha Boötis (the Herdsman). This star, located 37 light-years from Earth, is a K0-class red-orange giant with 1.5 times the mass of our sun, and about 100 times the output of the sun in visible wavelengths. Arcturus is visible from everywhere on Earth except the extreme southern latitudes. For observers in mid-northern latitudes, only Sirius in Canis Major (the Big Dog) shines brighter. Arcturus’ name derives from the expression “Guardian of the Bear” because it trails Ursa Major (the Big Bear).
The third week of April offers a final opportunity to view the winter constellations in a dark sky before they sink into the west and conjunction with the sun. The bright stars of Orion (the Hunter) and his faithful, furry companion Sirius remain visible on moonlit evenings. After dark, the giant hunter is already leaning westward in the west-southwestern sky — preparing for his summertime slumber.
Birds Surround the Egg Moon
When the Full Egg Moon crosses the night sky this week, it will be accompanied by several bird-themed constellations. The diamond-shaped constellation of Corvus (the Crow) sits 1.5 fist diameters to the right of the bright star Spica in Virgo (the Maiden). The bird is already low in the southeastern sky after dusk, and then flies higher, hour-by-hour. Cygnus (the Swan) will finish “taking off” from the northeastern horizon shortly after midnight local time. After 2 a.m., Aquila (the Eagle) will hunt in the eastern sky, to the lower right of Cygnus. And while it’s stretching the metaphor a little, the huge northerly constellation of Draco (the Dragon) sits directly above Cygnus, and winged Pegasus will rise to join the flock in the predawn.
Astronomy Skylights for the week of April 14th, 2019 by Chris Vaughan.
Keep looking up, and enjoy the sky when you do. I love questions and requests — so, send me some!