Exploring Jupiter and Saturn at Lime Hollow
March 12, 2003
Last Saturday evening, the two largest planets in the Solar System were the main guests at the Lime Hollow Center for Environment and Culture (LHCEC) in Cortland.
Astronomer Jim Rienhardt presented the giant alien worlds of Jupiter and Saturn in a public lecture entitled “Great Balls of … Gas?” on March 8 to an enthusiastic audience of adults and children at the Nature Center. Rienhardt began his lecture by putting the Solar System into perspective, literally. Using various size objects ranging from a maroon dodge ball to specks of dust, he showed just how truly large and small the planets are in comparison to the Sun and each other.
With the Sun being represented by the dodge ball, the largest planet in the Solar System – Jupiter – was no bigger than a large marble in comparison. Our Earth fit easily on a fingertip, and “poor” Pluto was little more than a dust speck.
Rienhardt explained that if the distances of the planets were stretched out to their true scale using his model with the Sun located in the Nature Center conference room, the edge of our Solar System, represented by Pluto, would have to be placed over half a mile away.
Having helped his audience grasp the incredible sizes and distances of the worlds in space, the resident astronomer introduced the main “stars” of the show: Jupiter and Saturn. Using slides of the giant planets and their moons, Rienhardt displayed the wondrous designs and colors of these alien realms.
Jupiter is an incredible world not only in size (over 1,300 Earths could fit inside that planet), but also in its cloud formations and colors. Jupiter’s famous Great Red Spot is a titanic hurricane twice the size of Earth that has been churning for at least four hundred years. Most of Jupiter consists of hydrogen and helium, turning into liquid metallic hydrogen far below the clouds, with a solid core the size of Earth at the very center.
Even Jupiter’s moons are large in both variety and numbers. The satellite Io is the most volcanic place in the Solar System. Europa, Ganymede, and Callisto all have oceans of liquid water deep under their ice crusts. Some scientists speculate that life may even exist in those distant seas.
To give you some idea of how fast astronomical discoveries are being made these days, Rienhardt told his audience that Saturday evening that seven new moons had just been found around Jupiter, bringing the total number of known satellites to 47. Only days after this lecture, five more moons have been revealed. Jupiter now has 52 moons circling it, and it is likely that this number is far from complete!
The next guest presented was Saturn, considered to be the most beautiful of all the planets. Much of this beauty comes from the incredible rings surrounding the second largest world in the Solar System. The other gas giant planets also have rings, but none of them can match Saturn’s in their beauty and complexity. The audience let out gasps of amazement when they saw close-up images of the rings from the Voyager spacecraft taken in the early 1980s.
Saturn also has its own collection of incredible moons. Titan is larger than the planet Mercury and has an opaque atmosphere of nitrogen twice as dense as Earth’s! From space Titan looks like an orange tennis ball. The astronomer also showed the moon Mimas, which has a giant crater from an impact with a celestial object that, had it been much larger, would have shattered the entire moon and probably created a new ring system for the planet.
A visitor from Earth is on its way to rendezvous with Saturn next year. The Cassini space probe, launched in 1997, will become the first vehicle to orbit the ringed giant in 2004 to study the planet in detail. Cassini will also be the first probe to land instruments on the moon Titan with its accompanying Huygens craft in December of 2004. Huygens will finally reveal to scientists what dwells under those mysterious orange clouds.
The only disappointment of the lecture was the weather, which kept the audience from seeing Jupiter and Saturn for themselves through several telescopes that evening. Rienhardt did provide current sky charts to his listeners for when the night skies are clear to find and view the giant planets with their own eyes.
Jupiter and Saturn are easy to find during March. Go outside shortly after sunset on a clear evening and look high up in the southwestern sky. Jupiter is easy to spot as the bright white star-like object in the constellation Cancer. Saturn is further west as a fainter but still bright yellowish “star” above the constellation Orion, which is easily recognizable with its three “belt” stars. If you have a telescope you can see Jupiter’s four largest moons as small points of light around the planet, along with dark bands of clouds on the planet itself. Saturn’s rings should also be visible even in small telescopes. The rings are now at their most visible in thirty years.
The Lime Hollow Center for Environment and Culture intends to explore much more of the Universe in the coming months. Plans are in the works for the formation of an astronomy club where the public can share in their enthusiasm for the night sky with others. Please contact LHCEC for further information through their Web site at:
For an introduction to astronomy, visit Jim Rienhardt’s STARLITE Space Science Resources Web site here:
Published in The Cortland Standard, March