what if Earth and Mars switched places?

Why Pluto is not a planet like Uranus?

hello friends in the early to mid-2000s

scientists are discovering a number of

plant like bodies with orbits lying in a

far-off region of the solar system

beyond Neptune because the objects were

close to the same size as that then

ninth planet Pluto one of two things had

to be done either these new objects need

to be added to the list of planets or

the definition of what constitutes a

planet needed to be changed because

scientists refining these planet like

objects at a relatively rapid pace with

many more certainly to be found option

number two is chess after all without a

new definition the solar system might

end up with hundreds or even thousands

of planets so what exactly is a major

planet in 2006 scientists decided upon

three defining characteristics a major

planet is a body that orbits the Sun it

has enough gravity to assume a mostly

spherical shape and most importantly it

has orbital dumbness meaning that it is

cleared all objects such as other plants

or asteroids added past this

characterizations that major planets

apart from a newly defined dwarf planet

like major planet dwarf planets orbit

the Sun and have enough gravity to pull

themselves into a mostly round shape but

their defining factor is that they

haven't cleared the neighborhood around

their orbit

scientists can now use this

classification system to categorize most

of the new planet like objects that were

being discovered out beyond the orbit of

Neptune this new definition also meant

it Ceres the largest asteroid in the

asteroid belt between Mars and Jupiter

would now be classified as a dwarf

planet because it's large enough to be

around advice on gravity there's only

one issue of this new classification

system solar system's ninth planet Pluto

was no longer a what we called a major

planet because it's locked in its orbit

on the gravitational influence of

Neptune and it shares its orbital

neighborhood with other Kuiper belt

objects most scientists were perfectly

content with reclassifying pluto but

much of the nostalgic poets did not

agree with Pluto's demotion today Pluto

is by far the most popular of the dwarf

planet in the mid 19th century in early

20th century scientists were looking for

an unknown planet near left in Neptune

to sway it four-bit in what is

considered now to be a very lucky find

Clyde Tombaugh searched for this planet

come to the discovery of Pluto in 1930

scientists were delighted to discovered

Pluto named him a ninth planet they soon

discovered that Pluto was much too small

to be capable of swayed in Neptune

Corbett searched for this tenth planet

planet X continued for years but after a

closer examination of the mast orbits of

the ice giant the existence of a

significantly sized planet beyond

Neptune was largely discredited still

search for another major planet

continues to this day with new evidence

in 2016 pointing towards the possibility

of a planet larger than Earth existing

in the far reaches of our solar system

so that's a topic for another video

altogether in the last number of years

start your planet in the outer solar

system has led astronomers to discover

quite a few possible dwarf planets but

only five have been officially

recognized by the International

Astronomical Union this number includes

Pluto in series which we've already

discussed is the only two dwarf planets

that have been observed in great detail

and are known to certainly fit the

definition of dwarf plant these other

three are so far away that as of now

they have not been photographed in

significant detail regardless the IAU

decide at Eris go with because it is

more massive in Pluto and therefore most

surely massive enough to pour itself

into here the union also assumed that

two other objects or dwarf planets

Kamiya and Makemake this is because

these planets reflect enough sunlight

back towards Earth almost certain Lybia

large enough to be considered part

planet after these initial few dwarf

planets were added to the official list

astronomers have discovered many more

probable dwarf planets despite this no

other dwarf planets have been recognized

by the IAU and it's unclear whether or

not the organization will continue to

add to the official list