Pluto, New Horizons, Kuiper Belt

Why in news?
History was made on July 14 when NASA’s New Horizons became the first spacecraft to successfully fly by the dwarf planet Pluto, the last unexplored world in the Solar System. This it did after travelling a distance of nearly 5 billion kilometres since its launch in January 2006.

Source: Hindustan Times

Pluto and Kuiper Belt:

Source: Indian express

Some details:

• Pluto was demoted to dwarf planet status in August 2006 after the discovery of Eris, of similar size, in the Kuiper belt.
• the surface is very young, probably less than 100 million years old, and the only way to explain this is by rejecting the grand old theory of an inert Pluto made up of ice and rock. Instead, the dwarf planet is geologically active with an internal heat source that drives the engine, and it has some yet-to-be deciphered mechanism that refreshes the surface from time to time; tidal heating can be ruled out as Pluto does not orbit any giant planet. 
• Similarly, the existence of high mountains, possible volcanoes, fault lines, rift valleys and other features underlines the presence of active tectonics. Similar to the crater-free surface, a mountain range jutting out 3,500 metres above it is also less than 100 million years old, and is one of the “youngest surfaces seen in the Solar System”.
• Long Range Reconnaissance Imager (LORRI) aboard New Horizons spacecraft.

The three criteria of the IAU for a full-sized planet are:

1. It is in orbit around the Sun.
2. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape).
3. It has "cleared the neighborhood" around its orbit.

Significance for Science in India:

India’s Chandrayaan-1 and the recent Mars Orbiter Mission Mangalyaan, certainly rekindled interest in science among students. At a time when basic science appears to have become less attractive, expeditions such as these could help reverse the trend.

[Ref: The Hindu]