March 31, 2019 — Bright Galaxies for Dark Nights, Evening Mars, and Five Pre-Dawn Planets!
The Moon and Planets
This is the week of the lunar month when our natural satellite swings towards, and then past the sun, leaving our night time skies darker — just in time to hunt for spring galaxies!
The moon will begin the week as a beautiful old crescent on Monday morning, sitting less than a fist’s diameter to the right of bright Venus. Both objects will be low in the eastern pre-dawn sky. On Tuesday morning, the moon will shift eastward to sit below Venus — and then the moon will become lost from view until after the New Moon phase officially occurs on Friday morning. The next chance to see the moon, now a young crescent, will come in the western sky on Friday after sunset, and the weekend beyond.
Mars will continue to be an easy planet to see every evening this week, but only for a couple of hours after dusk. Mars will set in the west before 11 pm local time, so you are better off to seek it out right after full dusk. Once the sky has darkened, look for Mars as a medium-bright, reddish pinpoint of light 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. By the way — during the opening nights of this week, Mars will continue to remain near the bright open star cluster known as the Pleiades, the Seven Sisters, and Messier 45. But the Red Planet will slide farther from that clump of blue stars every night.
Very bright Jupiter has been catching the eye in the southern sky before dawn for some time. But this is the last week for it to be considered a pre-dawn object, because next week it will begin to rise before midnight.
The king of planets will rise shortly after midnight local time. By 5 am, it should still be visible in the sky over the southern horizon. Yellowish Saturn will rise at about 2 am local time this week — but, being dimmer than Jupiter, it will become lost in the southeastern twilight after about 5 am. Look for Venus as a very bright starlike object sitting very low over the east-southeastern horizon from 4:30 am local time until sunrise. Unlike airplanes, Venus will shine with a steady, unblinking light, and it won’t drift across the sky.
Finally, for a challenge, look for Mercury sitting very low over the eastern sky at about 5 am local time. And on Wednesday morning, distant Neptune will sit less than a pinky finger’s width below Mercury.
Bright Galaxies for Dark Nights
In late evening during early April every year, the Big Dipper stands upright in the northeastern sky. The bright star Alkaid marks the tip of its handle. The Pinwheel Galaxy is a spectacular, large face-on spiral galaxy, also designated as Messier 101, sits a palm’s width to the left (north) of Alkaid, forming an equilateral triangle with Alkaid and Mizar, the star at the bend in the dipper’s handle. Although relatively bright and close to us (21 million light-years away), the Pinwheel Galaxy is fairly dim because its light is spread out over a large patch of sky. It’s actually as wide as the full moon!
Searching about four finger widths (3.5°) from Alkaid in the opposite direction, you will come to the iconic spiral Whirlpool Galaxy, also known as Messier 51. This galaxy’s angular size (diameter in the sky) is much smaller, but it will appear brighter in your telescope. It also features a secondary galaxy core. The two galaxies are linked by a bridge of material.
Draw a line diagonally across the dipper’s bowl by connecting the stars Phecda to Dubhe, and then extend that line by an amount equal to their separation. There you will find Bode’s Nebula, otherwise known as Messiers 81 and Messier 82. M81 is a magnitude 6.9 spiral galaxy oriented not quite face-on to Earth, making it larger and brighter than M82. M82, located half of a degree to the north of M81, is smaller, but brighter due its nearly edge-on orientation. Several other fainter galaxies can be found within a few degrees of Bode’s Nebula.
For a bonanza of galaxies, aim a telescope at the sky midway between the stars Denebola, which marks Leo’s (the Lion) tail, and Vindiamatrix, the star that marks Virgo’s (the Maiden) left arm. This is the heart of the Virgo Cluster of galaxies. Dozens of brighter galaxies populate this area of the sky, including a curved row of them more than two finger widths long known as Markarian’s Chain. Those galaxies are also sitting about three fist diameters to the right of the very bright star Arcturus in Bootes (the Herdsman).
Astronomy Skylights for the week of March 31st, 2019 by Chris Vaughan.
Keep looking up, and enjoy the sky when you do. I love questions and requests — so, send me some!