Planets line up as summer arrives

Every so often the planets of our solar system appear to line up across our skies so that we can see several of them all together at one time. This happens because all the planets are moving in their respective orbits at different speeds. Johannes Kepler, in the 16th century, determined that planets closer to the Sun move faster than those that are farther away from our star. It is a complex geometrical dance that includes Earth (we are moving in our orbit at some 60,000 miles per hour — equal to traveling from New York to London in three minutes!

This June the eastern morning sky before sunrise will have six planets strung out along a 72 degree line along the ecliptic (the plane of Earth’s orbit around the Sun) on June 1. In order from the Sun about to rise in the east, these planets are Jupiter, Mercury, Uranus, Mars, Neptune, and Saturn. The thin waning crescent Moon will appear to move down this line from right to left toward the horizon from June 1-4.

Four of these planets will be visible with the unaided eye; but Uranus and Neptune will require binoculars to see. Mercury will be rather challenging despite being fairly bright because it is already low to horizon on June 1 and loses altitude after that.

Saturn rises first and so it is the highest; at the top of the diagonal line of planets running left to right from the eastern horizon. Saturn rises at 2 a.m. and is well up by 4 a.m. This year and next when we look at Saturn through a telescope its rings seem to disappear. The plane of its rings are almost seen on edge right now, so the telescope will show practically a full disk of Saturn.

Neptune is about 10 degrees (about the width of clenched fist held up against the sky) below and left of Saturn. But the best way to find Neptune occurs later on June 28 when the waning gibbous Moon is just below Neptune. Look for a bluish dot just above the Moon with binoculars or telescope then.

Mars rises around 3 a.m. and will be easily seen just a few degrees left of the waning crescent Moon on he morning of June 2.

Uranus and Mercury will be close together on June 1; Mercury bright enough to see, but low, in some twilight near the horizon, so use binoculars to seek Uranus to the right of Mercury. It will be a challenge.

Finally Jupiter comes up below Mercury and is the brightest of the six planets and will be easy to see, though close to the horizon. By June 30, Jupiter will have greater altitude before sunrise and can be seen sitting right above Aldebaran, the brightest star of constellation Taurus the Bull. Also on June 30 Mars will be up and to the right of Jupiter, with the crescent Moon up and right of Mars. Uranus then may be spotted halfway between Mars and Jupiter (with binoculars — a greenish dot of light).

Meanwhile Summer Solstice arrives (the first day of summer) on June 20. The Sun that day at noon will peak at its highest altitude above the southern horizon for the entire year. All the June days around the Solstice will experience the greatest amount of daylight and least amount of darkness for the year.

Full moon in June is on June 21 and the 27, the gibbous Moon will be just above Saturn around 3:30 a.m.