This Week’s Sky: June 15 to 21

The summer solstice and planets passing by the crescent Moon are highlights of this week.

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.

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 – Summer 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, for an annular solar eclipse.

The partial eclipse will not be visible from Canada, but can be seen throughout eastern Africa, southern Europe and the Middle East, most of Asia and Southeast Asia. For those who aren’t in the vicinity — or who have bad weather — look for livestreams of the astronomical event online.

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. 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 per cent 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 degrees. 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. Proper solar filters will be required to view any portion of this eclipse in person.

Chris Vaughan is a science writer, geophysicist, astronomer, planetary scientist and an “outreach RASCal.” He writes Astronomy Skylights, and you can follow him on Twitter at @astrogeoguy. He can also bring his Digital Starlab portable inflatable planetarium to your school or other daytime or evening event. Contact him through AstroGeo.ca to tour the universe together.