SKY GUIDE: This map represents the night sky as it appears over Maine during June. The stars are shown as they appear at 10:30 p.m. early in the month, at 9:30 p.m. at midmonth, and at 8:30 p.m. at month’s end. Venus and Mars are shown at their midmonth positions. To use the map, hold it vertically and turn it so that the direction you are facing is at the bottom. Sky Chart prepared by Seth Lockman

The month of June is named for Juno, who was the queen of the gods and the wife of Zeus. She had the power to see through a veil of clouds that Zeus put up. Our latest mission to Jupiter is also named Juno and it is doing much the same for us, except that it uses scientific instruments that humans designed using the principles of mathematics to see through the clouds of Jupiter instead of magical powers.

Summer starts at exactly 11:32 p.m. on June 20 for us in the northern hemisphere. This marks the longest day of the year and the highest altitude that the sun will reach above our horizon, which is 68 degrees for us at this latitude. This particular June is packed full of incredible events: a 74% partial solar eclipse; a comet named 7P/Pons-Winnecke; a couple of asteroids at their best, Juno and Vesta; all 5 planets are visible and about evenly split between the morning and evening sky; some nice conjunctions with the moon; Mars crossing through the Beehive star cluster; a meteor shower called the Bootids; and the anniversary of the most explosive natural event to occur on Earth in over 100 years.

Even though it will only be a partial solar eclipse, the eclipse on the morning of June 10 will be the major highlight. We are in an eclipse season again and the northeast was the only part of this country that could not see any of the May 26 total lunar eclipse. Now the roles are reversed. The northeast will see most of the sun covered by the moon during this annular solar eclipse.

To see the entire ring of fire that defines an annular solar eclipse, you would have to travel north to Polar Bear country by Hudson Bay in Canada. The moon’s shadow cone will not quite be able to touch the earth during this eclipse because it will be just a little too far away near apogee to completely cover the sun, hence creating only an annular or ring-shaped eclipse. The path of the antumbra will trace a narrow arc across the earth stretching 4,831 miles starting by Lake Superior and connecting Canada, Greenland, and Russia.

This time, the greatest part of this eclipse will occur just south of the northernmost permanently inhabited place on Earth, Alert, in Nunavut, Canada at over 80 degrees north latitude, or over 13 degrees north of the Arctic circle. For us in Maine near Portland, the sun is already about half eclipsed when it rises at 5 a.m. Then the moon continues to cover the sun more and more from right to left. It will be 74% covered by 5:30 a.m. and the penumbral shadow of the moon will leave the sun by 6:30 that Thursday morning.

Our next-door planetary neighbors, Mars and Venus, will still be our evening planets all this month. Look west half an hour after sunset and you will see Venus in Gemini and Mars in Cancer. On June 11, a very slender waxing crescent moon will pass just 3 degrees below Venus. Mars is about 15 degrees up and to the left along the ecliptic and near Castor and Pollux in Gemini. Notice that the closer one, Pollux, is about the same brightness and orange hue as Mars. Then keep watching each clear night as Mars crosses right through the Beehive open star cluster in Cancer the Crab on June 22 and 23, just after summer started. Mars passed right below the Pleiades in Taurus on March 4 of this year. Venus is nearly fully lit by the sun now and it will set just before 10 p.m. each night, followed by Mars about an hour later. When you look at Mars now remember that China successfully landed a rover on Mars a few weeks ago.

Saturn starts the month by rising just after midnight, but it will rise 2 hours earlier by the end of June. Then Jupiter rises about an hour later in Aquarius, 15 degrees to the east of Saturn. Notice that Jupiter is 15 times brighter than the ringed planet. They are both getting brighter and closer now as they approach their oppositions later this summer. Jupiter will end its direct, eastward motion on June 21 and begin its retrograde motion back toward Saturn. Mercury will show up in the morning sky again during the last week of this month.

An asteroid named Vesta will reach 7.5 magnitude and move from Leo into Virgo this month. An asteroid named Juno, with the same origin in names as the month of June, will reach opposition on June 6. It is 84 miles across, about four times smaller than Vesta and about 10 times fainter.

A minor meteor shower named the Bootids will peak on June 27 in the constellation of Bootes near the Big Dipper. The brightest star in Bootes is named Arcturus, and you can find it easily by just following the arc of the Big Dipper’s handle. The saying goes “Arc to Arcturus and speed on to Spica.” You may see more meteors this year than usual since it is caused by the dust trail of Comet Pons-Winnecke which orbits the sun every 6.4 years and is now visible in our sky in Capricorn, right between Saturn and Jupiter. You will need a telescope to see it since it will only reach 11th magnitude, or 100 times fainter than anything you could see without optical aid.

JUNE HIGHLIGHTS

June 1: The moon passes near Jupiter this morning.

June 2: Last quarter moon is at 3:24 a.m. Mars passes near Pollux.

June 3: In 1948, the largest telescope in the world at the time, the 200-inch Mt. Palomar reflecting telescope, was dedicated.

June 4: The Compton Gamma Ray telescope came back to earth in 2000 after nine years in space and discovering about one new and extremely powerful gamma ray burst every day.

June 5: In 1989, Voyager 2 passed close to Neptune which was broadcast live and called “Neptune all Night.” They discovered ice volcanoes on Triton that night and many other amazing things.

June 10: New moon is at 6:53 a.m.

June 12: The moon passes just north of Venus this evening.

June 13: James Clerk Maxwell was born in 1831. He is known as the father of modern physics for bringing together electricity, magnetism, and light as different manifestations of the same phenomenon. The moon passes near Mars this evening.

June 16: In 1963, Valentina Tereshkova became the first woman in space.

June 17: First quarter moon is at 11:54 p.m.

June 18: In 1983, Sally Ride became the first American woman in space.

June 20: The summer solstice is at 11:32 p.m.

June 22: In 2000, NASA announced that it had found evidence of former liquid water on Mars.

June 24: Full moon is at 2:40 p.m. This is also called the strawberry or flower moon.

June 26: Charles Messier was born in 1730. He was a French comet hunter who made a catalog of 110 objects that turned out not to be comets because they did not move. He did discover about a dozen comets in the process.

June 29: George Ellery Hale was born in 1868. He designed and built the four consecutive largest telescopes in the world from 1899 right up to the 200-inch Mt. Palomar telescope dedicated in 1948.

June 30: In 1908, a comet or asteroid that was about 100 feet in diameter exploded about 5 miles high over Tunguska, Siberia with the force of 20 megatons of TNT. This leveled 80 million trees over 1,000 square miles, but did not leave a crater.

Bernie Reim of Wells is co-director of the Astronomical Society of Northern New England.