Earth’s closest companion, the moon, cozies up with the brightest objects in the night sky this week, while the most distant ice giant poses for great views through backyard telescopes.
Moon and friends. After nightfall on Monday, June 9, look for the waxing gibbous moon to ride in the middle of a perfect celestial alignment of four objects in the southeast sky. Left of the moon is Saturn, while to its right reside Spica and Mars. Can you see the color differences among the three starlike objects? The entire lineup will be visible most of the night, until they set before 3 a.m., local time.
Meanwhile, lucky sky-watchers located in the South Sandwich Islands and the southern tip of South Africa will get to see the moon pass in front of, or occult, Saturn.
Make sure you check out Saturn and its magnificent rings through a backyard telescope. The rings themselves are made of countless chunks of ice and rocks and are only a few miles thick. Right now, the rings appear tilted some 20 degrees toward the Earth, which adds to the drama of their appearance when seen through the eyepiece—especially under high magnification.
By the next evening, Tuesday, the moon will have jumped to the other side of Saturn and be even closer to the “Lord of the Rings,” at only 4 degrees away.
Neptune full stop. Monday, June 9, is when the most distant large planet in the solar system becomes stationary, meaning that its motion in the sky has slowed and it has reached a seeming standstill before it starts moving again, back in the opposite direction against the background stars.
This funny back-and-forth path, a pattern followed by all the planets, happens in the sky over the course of weeks and months. It is an illusion created when we observe our neighboring worlds from our vantage point on our own moving planet Earth.
Neptune lies some 2.8 billion miles (4.5 billion kilometers) from Earth and shines at 7.8 magnitude in the constellation Aquarius. That makes it barely visible, a tiny blue-colored star in binoculars and a small disk among a field of pinpoint stars in a backyard telescope.
The planet rises in the southeast, well after local midnight. It will climb about a quarter of the way up the southern sky by dawn, making this a great time to hunt it down.
Backyard astronomers with medium-aperture telescopes measuring at least 12 inches (30.5 centimeters) can try spotting Neptune’s largest moon, Triton, shining at magnitude 13.
Sky and Telescope has a great finder chart here.
Moon and Antares. By Wednesday, June 11, the moon will have sunk down in the southeast evening sky, shining near a bright orange star in the zodiacal constellation Scorpius.
The near full moon appears to be caught in the claw of the mythical arachnid’s claw, next to the constellation’s brilliant ruddy eye, the star Antares.
The cosmic pair will appear separated by approximately 7 degrees, a little more than the width of your fist held at an arm’s length.
Jupiter challenge. About a half hour after local sunset on Saturday, June 14, begin your hunt for the king of planets, which will be shining low in the northwest. Jupiter gleams bright among the fainter stars of the constellation Gemini, and sets less than two hours after sunset.
Although the gas giant’s disk appears big through telescopes, it will be a challenge to spot atmospheric details because of its low altitude.