The month of June is named for the Roman goddess Juno, who was also the wife of Jupiter. The Greek equivalent is the goddess Hera. The word June also has its origin in Latin meaning the “younger ones.”
This month always marks the beginning of summer for us in the northern hemisphere. This year that will happen at 12:24 a.m. on June 21. This is the highest point the sun will reach in our sky for the year. The sun is in Gemini in June, but you can’t see the zodiac constellation when the sun is in it. Gemini the Twins is a winter constellation in the Winter Hexagon near Orion.
The summer solstice also marks the shortest night/longest day for us in the northern hemisphere. If you would photograph the sun every few days at any consistent time of day with a fixed camera, the pattern for the whole year would trace out a figure 8, called the analemma. You can also create this shape by just tracing the length of the shadow of a fixed object for the year.
Even though the nights are getting shorter, we still have plenty of night to enjoy the sky above us from this latitude. Saturn will be the “star” of the month, since it will reach opposition on the 14th. That means the superior planet (all the planets from Mars through Neptune) is directly opposite the earth from the sun. The moon does this every month at full moon. On this day the planet will rise at sunset, reach its highest point in our sky at midnight, and not set until sunrise. However, for this opposition Saturn will be at its most southerly in the sky, which means it will not get as high in our sky as it usually does during its opposition, which happens every 13 months.
Jupiter will share the limelight with Saturn in the evening sky. The King of the Planets was at opposition back on April 7, so it is fading out a little more each evening but is still closer and brighter than usual. It will end its retrograde against the fixed background of stars on June 9. Notice that it will be working its way back eastward toward Spica, the brightest star in Virgo all month and throughout the summer. It will reach about 10 degrees directly above Spica on Sept. 11. Spica is at least a double star and located about 262 light years away.
Jupiter now rises well before sunset, so it is already high in our southern sky by the time it gets dark. It will set by 1 a.m. by the end of June. As you watch Jupiter this month, remember that we have a very appropriately named little satellite orbiting around this giant planet every 53 days. It is named Juno and it has already completed six of these orbits. They are highly elliptical, getting as close as 2,200 miles above the poles and then traveling way out to 1.6 million miles. This way Juno spends much less time in Jupiter’s very powerful and dangerous electrical fields, which would fry all of its sensitive and sophisticated scientific instruments.
Juno was launched on Aug. 5, 2011. After a gravity assist from Earth in October 2013, it arrived at Jupiter exactly on schedule, July 4, 2016. Juno recently took some incredible pictures of ever-changing patterns of thousands of colorful, swirling clouds around its south pole. It looks much more like the sky in Van Gogh’s Starry Night than what you would expect. Any individual can help to choose the pictures that Juno will take and even help to process them. Just go on their website (missionjuno.swri.edu/junocam), for details. This is another great example of citizen science, one small aspect of our taxes put to great use. We can even materially participate in gathering and processing this important information so that we can share the knowledge.
Notice that Jupiter is exactly two magnitudes, or 61/4 times brighter than Saturn now. A waxing gibbous moon will pass just 2 degrees above Jupiter on the evening of June 3, and will then catch up with the next planet along the ecliptic, which is Saturn. The moon continually moves eastward at about 12 degrees per day. It will catch up with Saturn a week later and pass directly above the ringed planet on June 10.
Venus is still the bright morning planet. It will fade rapidly in our sky this month as it pulls farther ahead of us in its faster orbit around the sun. It will be half illuminated on June 3 when it reaches its greatest western elongation from the sun at 46 degrees. Then it will get fuller, similar to a waxing gibbous moon, even while it is getting fainter in our sky.
We will finally lose Mars in our evening sky this month. It was with us as an evening planet all winter and spring as it was setting about the same time each evening. Then the red planet will not show up again in the morning sky until August.
When summer starts Mars will be about as far away as it can get from us – about 250 million miles away – since it will be halfway to its next opposition on July 27 of next year. Its last opposition was on May 22 of last year. Mars gets to opposition only once every 26 months, instead of every 13 months like the other superior planets.
The next opposition of Mars will be almost as good as the one on Aug. 27, 2003. At 34 million miles, that was the closest Mars got to earth since the Stone Age, 60,000 years ago. Even at opposition, Mars has a wide range of distances to Earth. They can range from about 33 million miles to 63 million miles away. When you catch Mars fading out early this month, remember that the largest rover we ever landed on Mars, named Curiosity, has been there almost five years now, and is still making interesting discoveries and taking great pictures.
JUNE HIGHLIGHTS
June 1: First-quarter moon at 8:43 a.m.
June 3: Hale’s 200-inch telescope was dedicated on this day in 1948 on Mt. Palomar. The moon passes just two degrees above Jupiter tonight.
June 4: In 2000, the Compton Gamma Ray Observatory was allowed to re-enter our atmosphere after nearly 10 years of observing our high-energy universe in gamma ray wavelengths.
June 5: On this day in 1989, Voyager 2 made its closest approach to Neptune. They were showing live, unprocessed images as they came arrived in a great program called Neptune all Night.
June 9: Full moon is at 9:11 a.m. This is also called the Strawberry or Rose Moon. The full moon will be just 3 degrees above and to the left of Saturn.
June 16: On this day in 1963, Valentina Tereshkova became the first woman in space and is still the only solo space flight by a woman.
June 17: Last-quarter moon at 7:34 a.m.
June 20: Venus is near the waning crescent moon this morning.
June 21: Summer starts at 12:24 a.m.
June 23: New moon at 10:32 p.m.
June 26: Charles Messier was born on this day in 1730. He developed a catalog of 110 celestial objects while hunting for comets. He also discovered about a dozen comets in the process.
June 29: George Ellery Hale was born on this day in 1868.
Bernie Reim of Wells is co-director of the Astronomical Society of Northern New England.
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