In July, a very cool thing is going to happen. New Horizons, launched in 2006, will arrive at Pluto. I am not an astronomer, but I have always loved the planets in the stars. I had books on space as a child, and a homemade mobile of the solar system hanging from the ceiling of my bedroom. I devoured science fiction. I guess you could say I am an amateur (literally: lover).
For millions of years our ancestors have stared up into the heavens with wonder and fascination. Those who are spiritually awake look at the stars, the flowers and all of creation with awe.
When I look at your heavens, the work of your fingers, the moon and the stars that you have established; what are human beings that you are mindful of them, mortals that you care for them?
Ancient people noticed that the stars, while shifting, always remained in the same relationship to one another. There were, however five stars that tended to wander around the sky. The Greeks called these “wandering stars” or astēr planētēs (ἀστήρ πλανήτης). Those of us who have studied biblical Greek may recognize the word for “wandering.” Jude (1:13) refers to his opponents as “ἀστήρ πλανήτης,” wandering stars.
These wandering stars were given divine importance. We have come to know them by their Roman names: Mercury, Venus, Mars, Jupiter and Saturn. Occasionally other wanderers would appear. Today we would call them comets. These wandering stars were held as sacred. They had special significance. They were believed to portend theborth of great leaders and point the direction to important events.
Earth was not understood as a planet until the 16th century, and even then with considerable resistance from the church hierarchy. Many discoveries threatened the accepted order. Don’t miss this though: Copernicus was a polish priest.
Uranus is visible to the naked eye, but because it was so faint and its movement so barely perceptible, even though it was noticed even prior to Jesus’ birth, it was taken for a star until the 1700s, the first planet discovered by telescope.
Neptune was predicted by mathematical calculation before it was found. Anomalies in Uranus’ orbit led astronomers to believe there was gravitational pull from a larger body beyond Uranus. Neptune was found in the 1800s.
Likewise, there were some slight anomalies in Neptune’s orbit that led astronomers to begin searching for a ninth planet. In 1906 Percival Lowell began looking for what he called “Planet X.” Pluto was discovered in 1930, but alas, Lowell died in 1916. Ironically, he had indeed seen Pluto in a 1915 image but didn’t didn’t recognize it for what it was.
On February 18, 1930, the “planet” was discovered.many names were suggested (Zeus and Atlas, e.g.), but the final name was given by an 11-year-old girl: Pluto.
Much lore surrounded the search for Planet X. By the 50’s War of the Worlds shocked the country. Sci-fi geeks like me may recall the 1951 film The Man from Planet X.
Thing is, Pluto was one of many objects orbiting the sun in a group called the Kuiper belt. True, Pluto was the largest yet found, but there were problems. First of all Pluto is less than half the size of our moon. Second, Pluto is not much larger than one of its five known moons (Charon, discovered later). Some call Pluto-Charon a binary system, because they revolve around each other. Perhaps New Horizons will resolve this in July.
In 1977 another minor planet , Chiron, was discovered, pretty close to Pluto’s size. Scientists knew it would only be a matter of time before a body larger than Pluto was was discovered in the Kuiper Belt.
That time came in 2005. Eris was discovered, a body more massive than Pluto. What to do? Are they all planets then? Some said, “Yes.” How big is a planet? Must it have an atmosphere?
In 2006, the International Astronomical Union determined a planet must be able to be rounded by its own gravity, not be so large as to cause thermonuclear fusion, and have cleared the area around it of debris. Pluto was demoted to a planetoid. Opponents of this controversial decision would favor a broader definition of planet, making Chiron and Eris planets, along with perhaps dozens of other orbiting bodies.
There is much we don’t know about Pluto. New Horizons will teach us much. Does Pluto have an atmosphere? If so, made of what? Are there more than five moons? What is the topography like?
Since it passed Jupiter, New Horizons has been asleep. In December they woke it up without a hitch. New Horizons arrives mid-July. These are exciting times to be alive.