Ask Question. Asked 10 years, 4 months ago. Active 7 years, 10 months ago. Viewed 29k times. Improve this question. Annika Peterson Annika Peterson 4 4 gold badges 9 9 silver badges 12 12 bronze badges. Add a comment. Active Oldest Votes. IMHO Brown dwarfs New observations are making it clear that objects may exist ranging smoothly from Jupiter, an undisputed planet, right on up to objects that are indisputably stars.
Improve this answer. Andrew Andrew 9, 1 1 gold badge 28 28 silver badges 44 44 bronze badges. I'm sorry if that was unclear. However, considering the fudge factors regarding space debris as mentioned in point 5, I think Kuiper belt objects are a lesser argument against Pluto maintaining its previous major planet status.
Pluto's orbit is tilted enough that it never actually comes very close to Neptune. This is why Pluto is not classified as a planet, but rather as a dwarf planet.
Dromaeosaur Dromaeosaur. Featured on Meta. Now live: A fully responsive profile. Linked NASA 's Dawn spacecraft was launched in and entered into orbit around Ceres after first observing nearby asteroid Vesta. Dawn allowed astronomers to see detailed images of the dwarf planet for the first time and find out more about its composition and surface.
An artist's representation of the dwarf planet Makemake and its moon MK2. Parker SwRI. Makemake was discovered in , just a few months after Eris was found, and by the same team of astronomers.
It is located in the Kuiper Belt, a ring of icy debris beyond the orbit of Neptune — around 30 to 50 times farther from the Sun than Earth is. Astronomers say that Makemake is likely reddish in colour, similar to Pluto. In , a moon nicknamed MK2 was discovered orbiting the dwarf planet. Makemake takes over years to complete a trip around the Sun. An artist's representation of the dwarf planet Haumea and its two moons, Hi'iaka and Namaka.
Credit: A. Field STScI. Haumea was discovered in in the Kuiper Belt beyond the orbit of Neptune. Since the new definition, three objects in our solar system have been classified as dwarf planets: Pluto, Ceres and Eris. For 76 years until , Pluto was known as the ninth planet in our solar system. Since then, Pluto has been relegated to dwarf planet status. Discovered in , Pluto is a member of the outer region of our solar system known as the Kuiper belt.
It has a highly inclined and eccentric year orbit around the Sun. As the second-largest known dwarf planet, Pluto is approximately 2, km in diameter and is composed primarily of ice and rock. It is very difficult to precisely determine the diameter of Pluto since it is so far away. Pluto is, on average, 40 times farther from the Sun than Earth. The New Horizons spacecraft, scheduled to arrive at Pluto in , will be able to provide us with more accurate measurements of Pluto.
Pluto's surface is made almost entirely of nitrogen ice, with traces of methane and carbon monoxide. Pluto has a thin atmosphere made of the same components of its surface: nitrogen, methane and carbon monoxide. Like a comet, Pluto's atmosphere freezes as it moves away from the Sun and the ices sublimate as it approaches the Sun. In , the discovery of Pluto's largest moon, Charon, gave scientists an opportunity to learn more about Pluto. The two icy objects eclipsed each other from Earth's point of view from allowing scientists to more precisely determine their diameters and masses.
A planet is a large object that orbits around a star or a stellar remnant. This is mainly due to its own gravity and gravity of the star that allows the planet to have an orbit around the star. The orbit is usually elliptical in shape, mainly depending on the gravitational force of the planet and the star.
The gravitational force of the planet is strong enough that it leads the planet to be rounded, i. A planet has also cleared its neighboring region of any other debris. The planetesimals, i. Also see: Difference between asteroids and planets. Hence, as per this definition, there are currently eight planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, in order of distance from the Sun.
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