Morning Moon meets Bright Planets, Mars Attacks a Star Cluster, and Some Easy Dark Sky Galaxies!
The Moon and Planets
This is the week of the lunar month when our natural satellite, fresh from yesterday’s full moon, will wane and rise later, eventually arriving at its Last Quarter phase next Sunday after mid-day. By that time, the moon will have set in the west for us in the Eastern Time zone. Last Quarter moons always rise near midnight and linger into the daytime morning western sky.
Here are the rest of the moon doings for this week…
When the waning gibbous moon rises from the southeastern horizon just before midnight local time on Monday, it will be positioned a palm’s width to the lower left (east) of bright Jupiter. As the pair crosses the sky together, the moon’s orbital motion will carry it farther away from Jupiter. You can watch both of them until Jupiter fades from view just before sunrise. At that time, they will be positioned over the southwestern horizon.
The moon will also dance with Saturn this week. When the moon rises from the southeastern horizon after 1:30 am local time on Thursday, it will be positioned 4 finger widths to the lower left (east) of yellowish Saturn. As before, the moon’s orbital motion will carry it noticeably farther from Saturn over the following hours. They will remain visible until about 5 am local time, when they will sit in the southern sky. Hours earlier, observers in the southern tip of Africa, parts of eastern Antarctica, Kerguelen Islands, most of Australia, and southern New Zealand will get to see the moon pass in front of (or occult) the Ringed Planet.
You still have some evenings to catch a glimpse of Mars’ bright, reddish pinpoint in the western evening sky before it transitions fully into the sunset. This week, Mar is tickling the toes of Gemini (the Twins) and sets at about 11:30pm local time.
In the north-northwestern sky this evening (Sunday), Mars will be positioned only 0.25 degrees (or half of a moon’s diameter) to the right of the prominent open star cluster known as Messier 35 and NGC 2168. Mars and the star cluster’s many stars will all fit together into the field of view of a backyard telescope at medium magnification. Binoculars will also show this cluster under moderately dark skies. Look for another, dimmer open star cluster designated NGC 2158 sitting southwest of Messier 35.
The bright planet Jupiter will rise in the east at about 10:30 pm local time this week. It’s gradually making its way into position for our summer evening stargazing! For now, if you are walking through the house in your pj’s during the wee hours, Jupiter’s bright beacon might catch your eye through a south-facing window. Jupiter will reach its highest position, over the southern horizon, at about 3 am local time, and then it will descend towards the southwest as dawn arrives. If you’d like to see the famous Great Red Spot in your telescope, it will be crossing the planet around midnight on Sunday and Friday, and before dawn on Wednesday. No matter when you look, you can see the four bright Galilean moons arrayed to either side of Jupiter. Sometimes you’ll only see two or three of them if the rest are hidden by Jupiter itself.
Yellowish Saturn will be rising about 2 hours after Jupiter all summer, which positions it about 2.5 outstretched fist diameters to the lower left (east) of Jupiter in the pre-dawn sky and just to the left (east) of the stars that form the teapot-shaped asterism of Sagittarius (the Archer). Saturn will officially enter the evening sky on Friday, when it will rise a few minutes before midnight. Dust off your telescope because even a small telescope will show its rings!
Distant and dim, blue Neptune is in the southeastern pre-dawn sky, among the stars of Aquarius (the Water-Bearer). The planet will rise at about 3 am local time. But I’d wait for summer, when it will be available in the evening sky, to look for it.
Distant Uranus will sit a few finger widths above our next-door neighbour Venus in the east-northeastern sky on Monday morning. But the dawn twilight will make seeing the planetary pairing extremely difficult.
Dark Sky Galaxies
Towards the end of this week, the waning, late-rising moon will leave the evenings nice and dark worldwide — ideal for hunting for dimmer targets such as the spring galaxies in Leo (the Lion) that are observable in backyard telescopes. The well-known Leo Triplet consists of three spiral galaxies with the names Messier 65, Messier 66, and the Hamburger Galaxy (NGC 3628). All three galaxies will fit within the field of view of a telescope at low magnification. Their visual magnitudes range from 8.9 to 10.3, and all three have good surface brightness due to their near edge-on orientations.
Find the trio about 3 finger widths to the lower left (southeast) of the medium-bright star Chertan, which marks the lion’s rear foot. Another group of prominent galaxies is positioned about midway between the triplet and the bright star Regulus. The close pair of Messier 105 and NGC 3384 resembles headlights in the fog when viewed in a telescope. Two more galaxies, Messier 95 and Messier 96, are located a finger’s width below those “eyes”.
Although Ursa Major (the Big Bear) is a circumpolar constellation, it moves to a location very high in the northern sky in late evening during late May — a position ideal for observing the galaxy showpieces within it. The Big Dipper makes up most of Ursa Major. Drawing a line through the dipper’s bowl to connect the bright stars Phecda to Dubhe, and then extending the line by an amount equal to their separation, brings one to a pair of spiral galaxies called Bode’s Nebula. The larger and brighter galaxy is named Messier 81. It’s a magnitude 6.9 spiral galaxy oriented not quite face-on to Earth. The other galaxy, named Messier 82, is located half of a finger with to the lower right of Messier 81. It is smaller — but bright due its nearly edge-on orientation. Several other galaxies can be found within a few finger widths of Bode’s Nebula.
Astronomy Skylights for the week of May 19th, 2019 by Chris Vaughan.
Keep looking up, and enjoy the sky when you do. I love questions and requests — so, send me some!