Home >> Science & Nature >> Astronomy

How to Make a Project About Planet Pluto

Clyde W. Tombaugh has been credited with the discovery of Pluto in 1930. He made the discovery by comparing photographic plates in the region of Pluto, which were long exposures of a period of two weeks running. When the plates were compared, an object moved out of place in relation to the stars and other objects. When it was determined that the object did not have the trajectory of an asteroid of meteor, it was christened the ninth planet and given the name Pluto. As of Aug. 25, 2006, the International Astronomic Union has demoted Pluto to the status of dwarf planet. This new information has a good basis for forming a science project and asking questions about why Pluto no longer qualifies as a planet.

Things You'll Need

Large solar system mural
Felt pen
Cardboard panel

Instructions

- 1
  Write down the criteria for planet status in the solar system. Does the body orbit the Sun? Does the body have enough mass to give it a spherical shape? Is the body a smaller satellite of a larger rotating body? Has the body cleared its own path of other celestial objects that appear in its orbit?
- 2
  Discuss each planet, starting with Mercury, and how it orbits around the Sun. Verify that Mercury does in fact orbit around the sun. Ask the same question of each planet, up to and including Pluto. You may reference the orbital characteristics and rotational time periods for each planet, if you wish, just to draw comparisons. Ask if Pluto qualifies for this first rule of real planets. You can place a felt "X" mark on the large planetary mural for each planet in question, if it qualifies.
- 3
  Examine and discuss the physical appearance of each of the planets, starting with Mercury and moving outward. Determine if each planet meets the criteria for a spherical or round shape. Ask if this is due to the planet's mass; the answer is yes. Mark another "X" for each planet that appears round. Explain that Saturn is still round, even though it has an icy debris ring around it.
- 4
  Ask the last question pertaining to planet status in the solar system: Has the body cleared a path through its orbital plane, where no other objects exist? Discuss the orbital planes of each planet, starting with Mercury. Make a felt "X" for each planet that qualifies for this condition. When you arrive at Pluto, you will not mark it, since Pluto fails in this regard.
- 5
  Discuss why Charon, Pluto's major moon discovered back in 1978 and imaged in 1990, was one of the deciding factors in demoting Pluto to a dwarf planet. Pluto's size was definitively calculated by comparing it to Charon. Explain that Charon, being about half the size of Pluto, orbits around Pluto as though they share a common point of gravity. Another factor involves the discovery of Eris, another object that is larger in diameter than Pluto and carries 25 percent more mass. Eris orbits the Sun much further out than Pluto. Explain how this affects Pluto being considered a planet, when a larger body sits much further out in the solar system and is not regarded as a planet.
- 6
  Discuss why Pluto and its four moons, and the discovery of Eris, classified Pluto as a Kuiper Belt object rather than the ninth planet in the solar system.

Astronomy