1624. It was in this year that Polish astronomer Nicolas Copernicus advanced the heliocentric theory that the Earth and other planets revolve around the Sun. It was this highly controversial and contested theory that eventually revealed that the Earth was not the center of the universe and ultimately changed professional and amateur stargazing forever. Because of its present orbital velocity of 18 miles per second (111,600 miles per hour) through the Milky Way as a planetary dance partner, our planet Earth offers you the prime location for observing the majestic Planetary Dance.

It doesn't take an advanced degree or use of the Hubble Telescope to fully enjoy the revolving summer night skies. Simply keep in mind the following planetary observations and pull up a lakeside seat at dusk or dawn (along with binoculars, if desirable) to enjoy the nightly cosmic dance.

Mercury - The closest planet to our Sun, Mercury makes its orbit every 88 days. Because of this, Mercury alternates from being the evening star to the morning star. You will always locate Mercury above a flat, unobstructed horizon within approximately one hour before sunrise or after sunset, depending on the planet's orbit. This planet has three morning and three evening appearances each year, so it's important to keep your eyes open for these perennial events. The best time to view Mercury in the evening western sky is in the springtime. And the best time to view pre-dawn appearances of Mercury always come in the autumn.

Venus - Venus is the third most brilliant object in the sky, following the sun and the moon, so it should be easy to locate. It is so bright that you are sometimes able to see it in a blue daytime sky. Venus appears bright partly due to its close proximity and also because it is wrapped in white clouds that reflect more than 65 percent of the sunlight striking them; as compared to the moon which reflects about 12 percent of incoming sunlight. Like Mercury, Venus swings between morning and evening skies, visible from Earth, due to its 244-day orbit around our Sun.

Venus appears in the evening sky about six weeks after it has passed most directly behind the sun as seen from Earth. It starts low in the sky, but, evening by evening, grows brighter as it climbs higher in the west after sunset. At its highest above the sunset point, Venus is about halfway between the horizon and overhead. It is a lovely, conspicuous evening "star" that sets more than three hours after the sun.

After more than nine months as a morning "star," Venus once again disappears from view for earthly stargazers, this time because the planet is so far ahead of us in orbit that the sun comes between us and it. There is a period of several months in which we cannot see Venus. Then one fair evening you will spot her low in the west again.

Mars - The next planet out from Earth's orbit is Mars, which looks to the eye like a reddish "star." Mars' orbit around the sun takes only two years, in contrast to our single year. Thus Mars follows about a two-year cycle of observability in our sky.

The cycle begins when we first glimpse Mars on the opposite side of the solar system. At this time, Mars appears in our pre-dawn sky - low in the east, near the sun's glare - very faint and remote. Bright stars in their constellations rise earlier from one day to the next, and thus the stars sweep up in the east behind Mars. But Mars itself is destined to loom near the early morning twilight for many months.

Jupiter - The next planet out from Mars is Jupiter. After the sun, this is the largest object in our solar system. Jupiter is a mammoth world greater in volume (and more than double in mass) than all the other planets combined. We see Jupiter for much of every year. We do not see it only when the sun is between us and it. The planet emerges from the sun's glare in the east before dawn - much as Mars does - but because Jupiter moves more slowly with respect to the stars, it follows the stars' motion up and away from the dawn. It shifts into the midnight sky, and then the late evening sky, and then - like Mars - comes to opposition when it is rising in the east as the sun sets in the west, as we fly between Jupiter and the sun. Whenever it's visible, Jupiter is a bold starlike object in our sky, brighter than any star, but not as bright as Venus.

A steadily held pair of 7x50 binoculars will reveal four bright moons whose positions around Jupiter change from night to night. Each of these moons, dubbed Galilean Satellites because Galileo first saw them in 1610, is larger than our moon. One, Ganymede, is even bigger than Mercury. All told, Jupiter has 16 known moons at the present time.

Saturn - The last planet in our solar system known since antiquity - the last one visible to the eye alone - lies beyond Jupiter. Saturn is probably the solar system's most showcased object for telescopic observers. To the unaided eye and through binoculars, however, it looks nothing more than a bright, butterscotch-hued star.

No one would use a word like "brilliant" or "bold" to describe Saturn, even though the planet is brighter than most stars. Saturn is the faintest of the bright planets, and it moves most slowly of these planets among the stars, taking 30 years to orbit the sun once and thus 30 years to complete a single circuit around our sky. That is why some early stargazers called Saturn a name that means "oldest of the old sheep."

Saturn follows, more or less, the same pattern as Jupiter from one year to the next. We see it in the eastern, pre-dawn sky - then at midnight - then in late evening - then rising in the east at sunset as the planet comes to its yearly opposition. The appeal of Saturn is in the gentle quality of its bright golden light, and in the fact that this planet returns reliably, year after year, to nearly the same part of the sky. If you begin watching Saturn in the evening in autumn one year, as the world at your feet is becoming golden and dry, and cold winds are beginning to blow, you can be sure that Saturn will grace your evening sky at nearly that same season the following year. It does shift with respect to the stars, as all the planets do, but it does so with an impressive slowness.

The view through a telescope aimed at Saturn is nothing short of spectacular. Even a small telescope will reveal the planet's ring system composed of rock and ice particles that never formed a moon.

Lastly, throughout the seasons and closer to home, the amateur observer always has a ringside seat to the shifting phases of our glorious Moon; none of which is more spectacular than the monthly full moon. But did you realize that the full moon has other aliases? Guy Ottewell's Astronomical Calendar provides a comprehensive list of the names of the different full moons throughout the year.

Full Moon Names

January: Old Moon or Moon After Yule

February: Snow Moon, Hunger Moon, or Wolf Moon

March: Sap Moon, Crow Moon, or Lenten Moon

April: Grass Moon or Egg Moon

May: Planting Moon or Milk Moon

June: Rose Moon, Flower Moon, or Strawberry Moon

July: Thunder Moon or Hay Moon

August: Green Corn Moon or Grain Moon

September: Fruit Moon or Harvest Moon

October: Harvest Moon or Hunter's Moon

November: Hunter's Moon, Frosty Moon, or Beaver Moon

December: Moon Before Yule or Long Night Moon

Throughout all your moments at the lake this summer, be sure to save some of the most memorable moments for the post-dusk and pre-dawn glances heavenward. It is a dance that you won't want to miss.

By Lee Hoedl