As we finish off one season and begin another, it’s time to hunt down a spectacular ball of stars and watch as the moon plays with planets.
Great Hercules Cluster. On Tuesday, June 16, the moon enters a new phase, making it an ideal time to hunt down a stunning celestial snow globe in the constellation Hercules, the strongman.
Messier 13, also known as the Great Hercules Cluster, is a favorite deep-sky object for those with binoculars and backyard telescopes. Located nearly 24,000 light-years from Earth, the globular cluster is composed of nearly a half million stars held together tightly by gravity.
To find this stellar snowball, look for the constellation Hercules in the southeastern sky. While this ancient superhero's stars are not the brightest, four make a distinctive wedge-shaped trapezoid that marks his torso. The great cluster lies along an imaginary line drawn between the two stars on the right side of the trapezoid.
Far away from city lights it's possible for keen eyes to spot the cluster as a faint, fuzzy patch of light, but binoculars make it easy to find even within city limits. A telescope will begin to resolve the outer stars of this 100 light-year wide swarm of stars.
Moon and planets. Starting at dusk on Friday, June 19, and the next night, the waxing crescent moon shares the spotlight with the slowly converging planetary pair of Venus and Jupiter.
On Friday the moon will be below the two super-bright planets, low in the western sky after sunset. But by Saturday night, the three most brilliant objects of the night sky form an eye-catching celestial triangle. This is one photo opportunity you won’t want to miss.
Leo lineup. By Sunday, June 21, the moon will be higher in the southwest sky and tucked just to the lower-left of Regulus, the lead star in the constellation Leo, the lion.
In just a span of 20 degrees--or the width of two fists held at arm’s length--sky-watchers can observe the moon forming a gentle arc with Regulus, Jupiter, and Venus.
On June 30, the two bright planets will be at their closest approach. Stay tuned for more details in the coming days.
June solstice. Summer in the northern hemisphere and winter in the southern hemisphere officially begin at 12:38 p.m. EDT (16:38 UT) on Saturday, June 21.
During this season, the Earth’s northern axis is slightly tilted toward the sun such that the northern hemisphere gets more direct sunlight and experiences warmer temperatures. Locations south of the equator are tilted away from the sun. There, the sunlight is dispersed and colder temperatures dominate.
On this first day of the new season, and a few days afterward, the sun appears to rise at the same place on the horizon--hence the origin of the word solstice, which means “sun stands still” in Latin.
From solstice date onward, the days get shorter and the nights longer in the northern hemisphere. The opposite occurs in the southern hemisphere.