Could Pluto become a planet again?

It's long been a question that has divided many scientists - is Pluto a planet or not?

First discovered nearly 100 years ago, Pluto was known as the ninth planet in our solar system for decades.

But in 2006, scientists decided it didn't meet all the rules, and so it was reclassified as a dwarf planet.

However, Nasa boss Jared Isaacman has now suggested that the US space agency might look again at whether Pluto should be given its planet status back.

So, could our solar system once again have nine planets instead of eight? Keep reading to find out...

Pluto was officially discovered on 18 February 1930 by American astronomer Clyde Tombaugh.

He was using one of the most powerful telescopes at the time at the Lowell Observatory in the US state of Arizona.

It was soon classed as a planet, and stayed that way for more than 70 years, until 2006, when the International Astronomical Union (IAU) downgraded it to a dwarf planet.

A dwarf planet orbits the sun just like other planets, but it is smaller.

It is defined as being massive enough to be rounded by its own gravity but has not "cleared the neighbourhood" of other objects and is not a satellite.

However, earlier this week, Nasa boss Jared Isaacman told a US Senate Committee that he was "very much" wanting to make Pluto a planet again.

He added that "some papers" were underway at Nasa to "revisit this discussion".

Some people think that Pluto shouldn't be a planet, because it doesn't fit the official description of what a planet is.

In 2006, the International Astronomical Union (IAU) created a new definition for planets.

To qualify, an object must orbit the Sun, be nearly round in shape, and have "cleared its orbit" - meaning it is the largest object in its path.

Pluto meets the first two conditions but not the third, because it shares its orbit with other icy objects, in a region called the Kuiper Belt.

As a result, it was downgraded to a dwarf planet, and that's why some scientists think it should stay that way.

Some people say that Pluto has many features we normally associate with planets.

According to Nasa, Pluto is a "complex and mysterious world with mountains, valleys, plains, craters, and glaciers".

Pluto also has five known moons - Charon, Styx, Nix, Kerberos and Hydra.

Scientists who want Pluto reclassified point towards the fact that the IAU's description is outdated and needs to be changed as it is too narrow and doesn't reflect how complex space objects really are.

In addition, a lot has been discovered about Pluto since it lost its planet status in 2006.

Nasa's New Horizons mission - the only spacecraft to have explored Pluto up close - flew by the dwarf planet and its moons in 2015 and transformed our understanding of this distant object.

Before New Horizons, the best images of Pluto revealed nothing more than a few light and dark patches.

However, the spacecraft sent back many new pictures which showed Pluto in much more detail, revealing lots of scientific information about the dwarf planet.

And that's why some scientists say that it needs to be looked at whether it should become a planet again.