Answer. The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. Essentially Pluto meets all the criteria except one—it “has not cleared its neighboring region of other objects.”
According to the IAU, Pluto is technically a “dwarf planet,” because it has not “cleared its neighboring region of other objects.” This means that Pluto still has lots of asteroids and other space rocks along its flight path, rather than having absorbed them over time, like the larger planets have done.
When Pluto was reclassified in 2006 from a planet to a dwarf planet, there was widespread outrage on behalf of the demoted planet.
The eight planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Mercury is closest to the Sun. Neptune is the farthest. Planets, asteroids, and comets orbit our Sun.
In 1930, Pluto was discovered and officially named the ninth planet. However, in 1978, Pluto was determined to be too low in mass to have caused these perturbations, so the possibility of a tenth planet was proposed.
Neptune orbits our Sun, a star, and is the eighth planet from the Sun at a distance of about 2.8 billion miles (4.5 billion kilometers).
Pluto and its kin — round objects that shared the neighborhood of their orbit with other entities — were henceforth called dwarf planets. All other objects orbiting the sun would be known as small solar system bodies.
On May 1, 2023, Pluto began its retrograde in Aquarius, where it continuess its backward spin until it reaches Capricorn once again on June 11. Pluto will remain in Capricorn into until it retraces its steps into Aquarius in January 2024.
Pluto's brief life as a planet was over, dead at age 76.
Pluto follows the first two rules: It is round, and it orbits the sun. It does not, however, follow the third rule. It has not yet cleared the neighborhood of its orbit in space. Because it does not follow this rule, Pluto is no longer considered a planet.
Astronomers critical of the IAU instead suggest that a better definition is that a planet is simply a gravitationally rounded object that orbits around a star. It is not necessary for this orbiting body to have gravitationally swept out the debris in its orbit. By this definition, Pluto is a planet.
Pluto only meets two of the criteria required to be a planet. Because it is not gravitationally dominant, Pluto is considered a dwarf planet. However, only 5% of the world's astronomers voted on the redefinition, sparking controversy in the astronomy community.
The existence of this distant world is only theoretical at this point and no direct observation of the object nicknamed "Planet 9" have been made.
Planet Nine is a hypothetical ninth planet in the outer region of the Solar System. Its gravitational effects could explain the peculiar clustering of orbits for a group of extreme trans-Neptunian objects (ETNOs), bodies beyond Neptune that orbit the Sun at distances averaging more than 250 times that of the Earth.
One of Billions. Our solar system is made up of a star, eight planets, and countless smaller bodies such as dwarf planets, asteroids, and comets.
All of this new-found status would be fleeting though. Pluto would have at best a few hundred thousand, or possibly a million or two years to bask in the glory of being the last habitable world of the solar system. After that it too would return to the eternal cold of the cosmos.
Because the planet orbits so far from Earth, it takes about 248 years to transit through all 12 signs, meaning a Pluto return can't happen for a singular person, explains astrologer Vanessa Hardy. But it can happen for a country that's at least that old, as is the case with the United States this year.
The surface of Pluto is extremely cold, so it seems unlikely that life could exist there. At such cold temperatures, water, which is vital for life as we know it, is essentially rock-like. Pluto's interior is warmer, however, and some think there could even be an ocean deep inside.
Only our two nearest neighbours Venus and Mars have been landed on. Landing on another planet is technically challenging and many attempted landings have failed. Mars is the most explored of the planets. Mercury could be landed on but the speeds involved and the proximity to the Sun are challenging.
Uranus holds the record for the coldest temperature ever measured in the Solar System: a very chilly -224℃. The temperature on Neptune is still very cold, of course – usually around -214℃ – but Uranus beats that. The reason why Uranus is so cold is nothing to do with its distance from the Sun.
Like Jupiter and Saturn, Neptune is a gas giant—a big ball of gas surrounding an Earth-size core of hot liquids rather than rocks or other solid matter. And like fellow “ice giant” Uranus, Neptune's atmosphere is composed mostly of water, ammonia, and methane. It's the methane that gives Neptune its striking blue hue.