IT has a surface temperature of minus 225 degrees Celsius and was once the ninth and most distant planet from the Sun. But how big is it? Here’s all you need to know… How big is Pluto? Pluto is about one-sixth the width of Earth, at just 1,420 miles in diameter. It is far smaller even than […]
IT has a surface temperature of minus 225 degrees Celsius and was once the ninth and most distant planet from the Sun.
But how big is it? Here’s all you need to know…
Pluto is about one-sixth the width of Earth, at just 1,420 miles in diameter.
It is far smaller even than Earth’s moon, and 30 times smaller than Mercury, the smallest planet in our solar system.
New Horizons identified Pluto as the largest object in the Kuiper belt and, crucially, larger than Eris.
Charon is the largest of Pluto’s five moons, and is half the size of Pluto, so they are sometimes together called the double planet.
New Horizons showed Pluto not only to be larger than previously thought, but to have a thicker atmosphere and to be more geologically dynamic.
Pluto’s surface has broad plains and valleys, several kilometre-high mountain ranges, even volcanos.
The range of chemicals and colours found on Pluto differentiates it from others in the Kuiper belt, and some regions of Pluto appear new whereas others are very old.
Pluto is not currently classed as a planet. It is a minor, or dwarf, planet.
Pluto used to be the ninth planet in our solar system until the International Astronomical Union created a new system for classifying space objects in 2006.
It set out three characteristics that define a planet:
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Pluto failed on the third point.
Unlike Earth and the other eight large planets, Pluto has not cleared its surrounding wider area of any other large objects.
However, many astronomers were not happy about the decision to reclassify Pluto and the debate about its planetary status has rumbled on.
In 2017 a new idea was put forward, where a planet could be any round object in space smaller than a star.
This would reclassify many moons as planets, including Earth’s moon, and all the dwarf planets.
Pluto is between 4.67 billion miles and 2.66 billion miles from Earth.
Its distance from Earth changes because both planets move around the sun in elliptically-shaped orbits.
Pluto is so far away it took great technological advances such as the Hubble telescope before we could see it properly.
NASA’s New Horizons mission provided valuable high-resolution pictures, when it flew past Pluto in 2015.
The mission took 9.5 years before the ship reached Pluto from earth.
Here’s what you need to know, according to Nasa…
