There were once nine planets however back in 2006 the
International Astronomical Union stripped Pluto of its status by saying it was
too small to ‘pack sufficient gravitational punch’. Pluto is now known as a
‘dwarf planet’ leaving eight planets: Mercury, Venus, Earth, Mars, Jupiter,
Saturn, Uranus and Neptune.
Pluto was originally kicked out because it did not ‘meet the
criteria’ set up by the International Astronomical Union (AUI). Indeed Pluto
doesn’t meet the criteria because it is small and has a radius of around 750
miles, which is less than 20 per cent of the Earth’s radius and its
circumference is about 4,500 miles (this makes it smaller than our moon).
However not everyone agreed with the decision and the
Harvard-Smithsonian Centre for Astrophysics released a statement saying “a
dwarf fruit tree is still a small fruit tree, and a dwarf hamster is still a
small hamster.” Furthermore the Harvard-Smithsonian Centre held a debate and
let the audience decide if Pluto was a planet and the audience decided that
Pluto is in fact a planet by a 2-1 vote.
There is no definite answer that Pluto will return to its
previous status as a planet. But there is hope due to the fact that in 2015 a
spacecraft called New Horizons will be launched, the first ever spacecraft to
be sent to Pluto and should arrive at the ‘dwarf-planet’ by July of the same
year. New Horizons principal investigator Alan Stern, believes that Pluto is a
planet. “I think the public is better suited to this than astronomers, at
least,” Stern continued to say, “The IAU should never have pretended to have
the expertise to enter into this debate. It’s a matter for planetary
scientists, not astronomers.”
Do you think Pluto should be defined as a planet?
