Because of Pluto’s reduction in rank from the ninth planet in our solar system to just a dwarf planet, there has been increased focus on just what comprises this planet, which also has a Disney dog as its namesake.
There are so many speculations about the dwarf planet because no spacecraft has ventured out that far into the solar system – until just recently.
In January 2006, NASA launched an unmanned spacecraft called New Horizons, which will fly by Pluto; its major satellite (moon) called Charon and then onto various objects located on the Kuiper belt. It is estimated that by the year 2015, New Horizons will reach the atmosphere of Pluto and beginning transmitting important data about this celestial body.
Speculations about Pluto:
It will be a few more years before the world gets some definitive answers about Pluto. So until then, you have just educated guesses from scientists and astronomers about Pluto.
First of all, the brightness or apparent magnitude of Pluto is so dim that it cannot be seen without the aid of a telescope. Even with the most sophisticated of telescopes, many times Pluto appears to look like a star rather than the dwarf planet it is. Observations via telescope reveal that Pluto looks as if it is a brownish color with some hints of yellow.
When scientists discovered Charon, Pluto’s largest moon, back in the late 1970’s, they had to revise their opinion as to Pluto’s capacity to reflect light. Because Pluto was smaller than they originally thought, that meant that Pluto’s reflected qualities were a lot stronger than previously expected.
In fact, in order for it to even been seen via telescope, scientists believe that Pluto’s albedo (light reflectivity) was just a little below Venus’s albedo. And because Venus is second in the solar system line-up and easily visible to the naked eye in the sky, that means that Pluto’s albedo is pretty might considering its small size.
In regards to the surface of Pluto, scientists have had to depend on sparse images photographed from the Hubble Space Telescope. Plus, scientists extrapolated what the surface would be like based on the observations of Charon’s eclipses and the reflections off Pluto.
They theorize that the surface of this dwarf planet is icy with more of a methane composition on the side facing its moon Charon and carbon monoxide and nitrogen ice on the opposite of Pluto.
In regards to the atmosphere surrounding Pluto, it is very thin and mainly consists of methane and nitrogen when orbiting closest to the Sun. Orbiting away from the Sun, Pluto’s atmosphere freezes and drops to the surface of the dwarf planet.
And because there is little pressure on the surface of Pluto, it is believed that some of the atmosphere escapes into space whenever the dwarf planet orbits close to the Sun. The heat melts some of the ice and turns it into a gas, which then leaks out.
The temperatures on the surface can get close to a minus four hundred degrees Fahrenheit. There is no known presence of water in liquid form and no life is likely present on Pluto’s surface. Scientists are not sure exactly what the composition of Pluto’s internal mass is but they speculate that it may be up to seventy percent rock with the remaining composition being ice.
Because most of the information scientists and astronomers have on Pluto is educated guesses, the observations from the New Horizons spacecraft will be highly anticipated. Will the conjecture of the astronomers and scientists be proven or disproved? Unfortunately, everyone has to wait until at least the summer of 2015 to find out.