The week
gone by saw the world celebrate the 25th birthday of the internet on
23rd August. On this day in 1991, the public gained access for the
first time to the World Wide Web, which had been designed & deployed by
computer scientist Tim Berners-Lee at CERN in Switzerland.
But today’s
GK Nugget is about something else. On 24th Aug 2006 the International
Astronomical Union clarified the definition of a “planet”. It said that a
celestial body must meet the following criteria in order to qualify as a
planet:
1) It must be
round.
2) It must
orbit the sun.
3) It must
have “cleared the neighbourhood" of its orbit. This means that as a planet
travels, its gravity sweeps and clears the space around it of other objects.
Unfortunately,
Pluto (which was discovered on Feb 18th, 1930) doesn’t meet criteria
#3 & therefore it was classified as a Dwarf Planet. For the common man, this
was a shock, but amongst the circle of astronomers it wasn’t so surprising
since Pluto’s status had been in question for almost 30 years.
And so kids now, no
longer remember the names of the 9 planets by singing “My Very
Educated Mother Just Showed Us Nine Planets”.
Here are
some other interesting facts about the celestial bodies that revolve and rotate
around the Sun.
Along with
Pluto, there are 4 other Dwarf Planets in our solar system - Ceres, Eris, Haumea, & Makemake.
Pluto is
about the size of the moon. Nearly 170 Plutos could fit in the Earth.
It takes
approximately 248 Earth years for Pluto to make 1 trip around the sun. Since
astronomers discovered Pluto in 1930, it has not completed 1 trip around the
sun. It still has more than 150 Earth years to go!
Pluto is
so far away that it takes more than 5 Earth hours for light from the sun to reach it.
The sun's light reaches Earth in only 8 Earth minutes!
Venus is
the hottest planet. Even though Mercury is closest to the sun, it has no
atmosphere which holds in the heat. Venus, on the other hand, has a very thick
atmosphere which traps in the heat of the Sun.
Jupiter,
the largest planet in the solar system, acts as a protective gate keeper for
Earth, since its strong gravitational force pulls dangerous space debris into
its orbit before it gets to us.
There are
less than 2 days in a year on Mercury. That’s because it takes the planet 88 Earth
days to go around the Sun, but Mercury takes 58 Earth days to rotate on its
axis, i.e. to complete 1 Mercury day.
Seasons on
Uranus last for almost 20 Earth years. This is because the planet has an
orbital tilt of 82 degrees (compared to Earth’s 23.4 degrees). Uranus thus is
almost on its side which causes such odd weather.
The Sun, which
is 149.6 million kms away from us, is so huge that it makes up 99% of the mass
of the solar system. All the planets, asteroids, etc make up just 1% of the
mass.
