| 1 Astronomical Unit (AU) | = 93 000 000 miles |
| 1 light year | = 63 000 AU |
| = 58 00 000 000 000 miles (5.8 trillion miles) | |
| Speed of light | = 186 000 miles / second |
Pluto, is about the farthest planet (now dwarf-planet) located in the Kuiper belt, about 31-51 AU far from earth. That means light will take between 4-8 hours to reach pluto from earth.
To calculate - ( (31 or 51) * 93000000) / (186 000 * 3600) = 4.3 or 7.08 hours
I think its a great thing that we are looking at and questioning the definition of a planet as and when we discover new objects in the Kuiper belt. It shows whether we are ready to learn and question our own beliefs and assumptions. I don't think it matters to Pluto or for that matter any other object whether we call it a planet or a dwarf-planet. It will exist in the shape and form its supposed to and will move in the same fashion it is supposed it. Its more for us, whether we want to include more objects in our planet system or not based on our old definitions and new discoveries.
Refer to UCAR website for more details - http://www.windows.ucar.edu/
Read about Pluto, Kuiper belt objects (KBOs), 2003 UB313
Some other interesting facts
- Our milky way galaxy has about 200 billion more stars like Sun
- The width of our galaxy is about 90 000 light years
- The Sun (and our solar system) is revolving around the center of the Galaxy at a speed of 0.5 million miles an hour, but it still takes 200 million years for it to go around once.
