
A trip to Pluto takes four to 10 years.
Q&A with USC Professor Werner Dappen about dwarf planet Pluto
BY RUBY
Q: How cold is Pluto?
A: The average surface temperature on Pluto is 44 Kelvin (-229 Celsius or -380 Fahrenheit). For more, see www.universetoday.com/guide-to-space/pluto/temperature-of-pluto
Q: Is Pluto dusty?
A: No, we do not think so. Rather, we imagine the surface consists of frozen methane (which is a gas down here!), and so instead of ‘dusty,’ ‘icy’ is the better comparison, even if it is not water ice.
Q: Can people live on Pluto? If not, why?
A: Well, try to live at -380F … (of course, if you bring a full space habitat, with heating and air and water, sure, but I would not call it ‘live.’ Similarly, can I ‘live’ on the Moon? Normal speaking here implies a ‘no,’ even if we can build lunar bases, etc.
Q: How long would it take me to get to Pluto?
A: With current rocket technology, the trip can be done in four to 10 years, depending on if you are willing to burn more fuel to get less payload there or not. A NASA spacecraft—New Horizons—is actually on the way. Departed 2006 and arriving 2015.
Q: What is the surface like?
A: As said above, icy (but with frozen methane, not water).
Q: How many asteroids a year land on Pluto?
A: I would not speak of ‘landing.’ Next time an asteroid hits the earth and kills half of the human population (can happen every 100 million years or so), I would speak of an impact, not landing. But to your question, I have no clue (and depends on how small the asteroids are—dust grains? In that case, of course, many impacts. But if bigger chunks are meant (city size or larger), I do not know about the asteroid population there, and nobody knows, because out there, they are too small to be seen from here.
Q: Is Pluto a planet? If not, what is it?
A: On Aug. 24, 2006, the International Astronomical Union decided on a new definition of “planet,” which does not include Pluto. Pluto is now classified as a “dwarf planet” (or “Kuiper Belt object”). This renaming makes sense, because we believe there are many Pluto-class objects out there, and to be consistent, that would hike up the number of planets; demoting Pluto has prevented this. But we love its name, its history. For more, visit nineplanets.org/pluto.html