When Clyde Tombaugh discovered Pluto, he painstakingly photographed portions of the sky using a 13-inch telescope at Lowell Observatory and compared images from successive nights, looking for objects that showed movement between images. Objects that moved over the course of a night would be within in our solar system.
Mr. Tombaugh used a device called a blink comparator which allows the operator to view two photographic images, rapidly switching between the two. The human eye-brain combination is exceptionally good at seeing changes in the images. Objects that showed movement could be noted for further investigation. Any moving body that appeared where no object was known to exist would be a candidate for an undiscovered asteroids or planet.
After months of systematically photographing the sky and examining the photograhic plates in this way, Mr. Tombaugh recorded a moving object in the location where “Planet-X” was expected by Percival Lowell to be seen. This object was subsequently identified as a new planet and given the name “Pluto.”
As we now know with the benefit of additional decades of observation and analysis, Pluto is better described a a member of a class of objects referred to as Kuiper belt objects, a belt consisting of tens of thousands of objects, similar to the asteroid belt, but extending approximately 30-50 astronomical units from our Sun. So, Clyde Tombaugh really discovered the first object in a whole new class of objects in an unknown region of our solar system. While discovering a new planet is a great achievement in astronomy, reserved for only a few, discovering the first in an entire class of previously unknown objects is far more interesting and, frankly, worthy of greater recognition.
Mr. Tombaugh’s achievement speaks to the great power of carefully defining a question or problem and systematically looking for the answer by careful observation, documentation, analysis and adherence to defensible, logical interpretations of the data. This is the power of science.
Well… it looks like we may have another shot at this. Mike Brown and Konstantin Batygin have hypothesized, based on the the orbital motions of various Kuiper Belt objects, that a large planet, 1o times the mass of Earth may exist in the region of space 20 times farther from the Sun than Neptune. While the hypothesis seems sound and is presented by respected researchers, the methods of science demand proof. So the hunt is on for Planet Nine. (more…)