See what's up in the night sky for June 2020, including stargazing events and the moon's phases, in this Space.com gallery courtesy of Starry Night Software.
Monday, June 1 pre-dawn—Jupiter and Saturn Bracket a Globular Cluster
In the southern sky in the hours before dawn on the opening days of June, the globular star cluster Messier 75 will be positioned below and between the bright gas giant planets Jupiter and Saturn. In the dark, moonless sky before morning twilight begins, the magnitude 9.2 cluster should be visible in binoculars (red circle) and backyard telescopes as a small, fuzzy patch located approximately 1.5 finger widths below (or 1.5 degrees to the celestial south of) the two much brighter planets.
Wednesday, June 3 evening—Mercury at Greatest Eastern Elongation
In the western sky on the evening of Thursday, June 4, Mercury (orbit shown as red curve) will reach its widest separation, 24 degrees east of the Sun, for the current apparition. (Observers in eastern Asia and Australia will see Mercury's greatest elongation after sunset there on Thursday, June 4.) With Mercury sitting above the evening ecliptic (green line), this appearance of the planet will offer good views for Northern Hemisphere observers and poor views for observers in the Southern Hemisphere. The optimal viewing times at mid-northern latitudes fall between 9:15 and 10 p.m. local time. Viewed in a telescope (inset) the planet will exhibit a waning half-illuminated phase.
Thursday, June 4 from 11:22 to 13:52 GMT—Double Shadow Transit on Jupiter
From time to time, the small, round, black shadows cast by Jupiter's four Galilean moons can be seen in amateur telescopes as they cross (or transit) the planet's disk for several hours. On Thursday, June 4, observers on the west coast of North America and across the Pacific Ocean region can see a double shadow transit event. At 11:21 GMT, Europa's smaller shadow will join Ganymede's larger shadow already in transit. Ganymede's shadow will move off the planet at 13:52 GMT, leaving Europa's shadow to complete its crossing just before 14:06 GMT. The Great Red Spot will be visible on Jupiter during the latter stages of the event.
Friday, June 5 at 19:12 GMT—Full Strawberry Moon and Penumbral Lunar Eclipse
The moon will reach its full phase at 3:12 p.m. EDT (or 19:12 GMT) on Friday, June, 5. The June full moon, colloquially known as the Strawberry Moon, Mead Moon, Rose Moon, or Hot Moon, always shines in or near the stars of southern Ophiuchus, the Serpent-Bearer. This full moon will be accompanied by a penumbral lunar eclipse between 17:46 and 21:04 GMT. At greatest eclipse at 19:25 GMT, the moon will have only dipped about halfway into the Earth's northern penumbral shadow, barely darkening the moon's southern limb. The entire eclipse will be visible from most of Africa, the Middle East, central Asia, and most of Australia. Observers in the Americas will not see any portion of the eclipse—except along the eastern edge of South America, where the moon will rise as the eclipse is ending.
Saturday, June 6 evening—The Big Dipper as a Star Pointer
In early June the Big Dipper asterism, part of the larger constellation of Ursa Major, sits high in the northwestern sky after dusk. When viewed while facing northeast, the dipper's bowl opens on the right, towards its Little Dipper counterpart. Its handle extends upward. A line extended from Merak through Dubhe, the stars which mark the bowl's outer base and rim, respectively, will arrive at medium-bright Polaris, the North Star. Continue the arc of the dipper's bent handle and "Arc to Arcturus", the bright orange star in Böotes. Continuing that arc farther lets you "Spike to Spica", the brightest star in Virgo. A line extended from Mizar at the bend of the handle and diagonally through the dipper's bowl stars, will "Cast to Castor" in Gemini.
Monday, June 8 pre-dawn—Waning Moon near Jupiter and Saturn
The moon's monthly trip past the morning planets begins on Monday, June 8 in the southern sky during the hours before sunrise. The waning gibbous moon will sit a palm's width to the lower right (or 6.5 degrees to the celestial southwest) of very bright, white Jupiter and somewhat dimmer, yellowish Saturn. The trio will offer a lovely photo opportunity when composed with some interesting scenery.
Tuesday, June 9 pre-dawn—Gibbous Moon near Saturn and Jupiter
After 24 hours of motion, the waning gibbous moon will take up a position less than fist's diameter to the lower left (or 8 degrees to the celestial east) of bright Jupiter—with dimmer, yellowish Saturn above and between them. The trio will cross the sky together in the post-midnight hours, and will offer another lovely photo opportunity when composed with an interesting landscape.
Thursday, June 11 from 14:33 to 16:40 GMT—Double Shadow Transit and Great Red Spot on Jupiter
From time to time, the small, round, black shadows cast by Jupiter's four Galilean moons can be seen in amateur telescopes as they cross (or transit) the planet's disk for a few hours. On Thursday, June 11, observers in the western Pacific Ocean Region can see a double shadow transit. At 14:33 GMT, Ganymede's larger shadow will join Europa's smaller shadow already in transit. 127 minutes later Europa's shadow will move off the planet at 16:40 GMT, leaving Ganymede's shadow to complete its crossing at 17:54 GMT. The Great Red Spot will also be transiting during the event.
Friday, June 12 pre-dawn—Red Mars Passes Blue Neptune
In the southeastern pre-dawn sky on the mornings surrounding Friday, June 12, the faster orbital motion of reddish Mars (red line with dates:times) will carry it past distant, dim, and blue-tinted Neptune. At closest approach, Neptune will sit 1.5 degrees above (to the north of) Mars, allowing both planets to appear together in the field of view of amateur telescopes (red circle), although magnitude -0.19 Mars will shine nearly 1700 times brighter than magnitude 7.9 Neptune!
Saturday, June 13 pre-dawn—Half-Moon Near Mars
In the southeastern sky in the hours before dawn on Saturday, June 13, the waning half-illuminated moon will pass four finger widths to the lower left (or 4.5 degrees to the celestial southeast) of Mars. The duo will fit into the field of view of binoculars (red circle) and will make a nice photo opportunity when composed with some interesting landscape.
Saturday, June 13 at 6:24 GMT—Last Quarter Moon
The moon will reach its last quarter phase at 2:24 a.m. EDT, or 6:24 GMT, on Saturday, June 13. At last quarter, the moon always rises around midnight and remains visible in the southern sky during morning daylight. At last quarter, the relative positions of the Earth, sun, and moon cause us to see the moon half-illuminated—on its western (left-hand) side. At last quarter, the moon is also positioned ahead of the Earth in our trip around the sun. About 3½ hours later, Earth will occupy that same location in space. After this phase, the waning moon will traverse the final quarter of its orbit around the earth, on the way to new moon.
Sunday, June 14 overnight—Asteroid Pallas Passes the Coathangar Cluster
In the evening sky on the evenings surrounding Sunday, June 14, the orbital motion (red path with labeled dates:times) of the main belt asteroid designated (2) Pallas will take it 1.5 finger widths to the upper left (or 1.5 degrees to the celestial north) of the Coathangar Cluster in the constellation of Vulpecula. Also considered an asterism, the Coathangar is an easy target for binoculars—located midway between the bright stars Vega and Altair. The magnitude 8.94 asteroid and most of the cluster's stars will appear together in the field of view of backyard telescopes at low magnification (red circle).
Wednesday, June 17 before dawn—Crescent Moon near Uranus
In the eastern sky before dawn on Wednesday, June 17, the slender crescent of the old moon will pass less than a palm's width below (or 5 degrees to the celestial southeast of) Uranus. The blue-green, magnitude 5.8 ice giant planet will be visible in telescopes and binoculars (red circle), especially for observers at southerly latitudes, where the surrounding sky will be darker.
Thursday, June 18 from 18:33 to 19:13 GMT—Double Shadow Transit on Jupiter
From time to time, the small, round, black shadows cast by Jupiter's four Galilean moons can be seen in amateur telescopes as they cross (or transit) the planet's disk for several hours. On Thursday, June 18, observers across Asia can see a double shadow transit. At 18:33 GMT, Ganymede's larger shadow will join Europa's smaller shadow already in transit. 40 minutes later Europa's shadow will move off the planet at 19:13 GMT, leaving Ganymede's shadow to complete its crossing hours later.
Friday, June 19 before sunrise—Crescent Moon meets Venus
For about an hour before sunrise on Friday, June 19, the very slim crescent of the old moon will sit very close to the bright planet Venus. Look for the pair just above the east-northeastern horizon. The moon and Venus will fit together in the field of view of binoculars and backyard telescopes (red circle) and will make a nice widefield photograph when composed with foreground scenery. Observers in the Azores, the Canary Islands, northern and eastern Canada, Greenland, and the northern parts of Europe, Russia, and Mongolia can see the moon occult Venus between 07:20 and 08:07 GMT.
Saturday, June 20 at 21:44 GMT—June Solstice
On Saturday, June 20 at 5:54 p.m. EDT, or 21:44 GMT, the sun will reach its northernmost declination for the year, resulting in the longest daylight hours of the year for the Northern Hemisphere and the shortest daylight hours of the year for the Southern Hemisphere. The solstice marks the beginning of the summer season in the Northern Hemisphere, and winter in the Southern Hemisphere.
Sunday, June 21 at 6:41 GMT—New Moon and Annular Solar Eclipse
At its new phase on Sunday, June 21 at 2:41 a.m. EDT, or 6:41 GMT, the moon will be travelling between the Earth and the sun. Since sunlight is only shining on the side of the moon aimed away from us, and the moon is in the same region of the sky as the sun, the moon is normally hidden from view everywhere on Earth for about a day. But this new moon will occur 6.2 days past apogee, resulting in a thin-ringed annular solar eclipse visible across central Africa and southern Asia. The path of totality for this eclipse will commence at 04:48 GMT in central Africa. Greatest eclipse, with 98.8% of the sun blocked by the moon, will occur for 38 seconds at 06:40:05 GMT in northeastern India, with the sun at an altitude of 83°. After crossing southern China and a final landfall over Taiwan, the moon's shadow will sweep across the Philippine Sea and Pacific Ocean, narrowly missing Guam ten minutes before sunset. The partial eclipse will be visible throughout eastern Africa, southern Europe and the Middle East, most of Asia, and Southeast Asia. The eclipse will be live streamed. Proper solar filters will be required to view any portion of this eclipse in person.
Tuesday, June 23 pre-dawn—Neptune Reverses Direction
On Tuesday, June 23, distant blue Neptune will cease its regular eastward orbital motion through the background stars (red path) and begin a retrograde loop that will last until late November. On this date, you'll find the blue-green, magnitude 7.9 planet in eastern Aquarius, sitting a palm's width to the upper right (or 6.5 degrees to the west) of Mars and 3.5 degrees east of the medium-bright star Phi Aquarii. During the coming months, Neptune will move toward that star.
Tuesday, June 23 after dusk—Crescent Moon Buzzes the Beehive Cluster
In the west-northwestern sky after dusk on Tuesday, June 23, the young crescent moon's orbital motion (green line) will carry it closely past the northern edge of the large open star cluster known as the Beehive, or Messier 44, in the constellation of Cancer, the Crab. Observers in the Central and Mountain Time zones will be able to see the moon and the cluster while they are higher in the sky. The moon encounters this cluster frequently because the Beehive is located only 1 degree north of the ecliptic (green line). The reduced brightness of the crescent moon should allow you to see the cluster's stars and the moon in the field of view of your binoculars (red circle).
Saturday, June 27 evening—The Summer Triangle Arrives
After dusk in late June, Vega, Deneb, and Altair are the first stars to appear in the darkening eastern sky. Those three bright, white stars form the Summer Triangle asterism—an annual feature of the summer sky that remains visible until the end of December! The highest and most easterly of the trio is Vega, in Lyra. At magnitude 0.03, Vega is the brightest star in the summer sky, mainly due to its relative proximity to the sun – it's only 25 light-years distant. Magnitude 0.75 Altair, in Aquila, occupies the southern corner of the triangle. Altair is 17 light-years from the sun. By contrast, Deneb, which shines somewhat less brightly at magnitude 1.25, is a staggering 2,600 light-years away from us; but it ranks so high in visible brightness because of its greater intrinsic luminosity. The Milky Way passes between Vega and Altair and through Deneb, which sits high overhead as dawn begins to break.
Sunday, June 28 at 8:16 GMT—First Quarter Moon
The moon will reach its first quarter phase on Sunday, June 28 at 4:16 a.m. EDT, or 8:16 GMT. At that time, the relative positions of the Earth, sun, and moon will cause us to see the moon half-illuminated—on its eastern (right-hand) side. Sunlight striking the moon at a shallow angle produces spectacularly illuminated landscapes along the pole-to-pole terminator line that separates the lit and dark hemispheres. First quarter moons always rise around noon and set at midnight, so they are visible starting in the afternoon hours. The term "first quarter" refers not to the moon's appearance, but the fact that our natural satellite has now completed one quarter of its orbit around Earth, counting from the last new moon.