How Many Planets Are There? - CLT Livre

How Many Planets Are There?

How Many Planets Are There

Are there 8 or 9 planets?

Our Solar System Our solar system is made up of a star—the Sun—eight planets, 146 moons, a bunch of comets, asteroids and space rocks, ice, and several dwarf planets, such as Pluto. 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. They travel around our Sun in a flattened circle called an ellipse. It takes the Earth one year to go around the Sun. Mercury goes around the Sun in only 88 days. It takes Pluto, the most famous dwarf planet, 248 years to make one trip around the Sun.

Moons orbit planets. Right now, Jupiter has the most named moons—50. Mercury and Venus don’t have any moons. Earth has one. It is the brightest object in our night sky. The Sun, of course, is the brightest object in our daytime sky. It lights up the moon, planets, comets, and asteroids.

Are there actually 9 planets?

Searching for Planet Nine The discovery photograph of Pluto found by Clyde W. Tombaugh of Lowell Observatory in 1930. Astronomers today suspect that there might be a previously unknown Planet 9 in the distant solar system, but a new search at millimeter wavelengths has failed to find any convincing candidate.

  1. The Solar System has eight planets.
  2. In 2006, astronomers reclassified Pluto as a dwarf planet, the same class as contains Eris, Sedna, Quaoar, Ceres and perhaps many more solar system small bodies.
  3. These are defined approximately as bodies that orbit the Sun but that are not massive enough (unlike regular planets) to gravitationally dominate their environments by clearing away material.

Astronomers wonder, though, whether there might not really be a ninth planet previously undiscovered but lurking in the outer reaches of the solar system, perhaps in the giant Oort cloud of objects that begins hundreds of astronomical units (au) from the Sun and extends outward.

The notion that there may be a ninth massive planet in the outer solar system has taken on new appeal with recent data that show that the orbital parameters of some small bodies beyond Neptune (their inclinations, perihelions, and retrograde motions) seem to behave as though they had been influenced by the gravity of a massive object in the outer solar system.

Although these data suffer from observational biases and statistical uncertainties, they have triggered renewed interest in the idea of the presence of another planet. This speculative “Planet 9,” according to estimates, would be about 5-10 Earth-masses in size and orbit about 400-800 au from the Sun.

  1. A planet at this distance would be extremely difficult to spot in normal optical sky searches because of its faintness, even to telescopes like PanSTARRS and LSST.
  2. Most solar system objects were discovered at optical wavelengths via their reflected sunlight, but the sunlight they receive drops as one-over-their-distance-from-the-Sun squared; moreover, the reflected portion then travels back to telescopes on Earth and so declines again by a similar factor.

In the outer reaches of the solar system these objects, although cold, might emit more infrared radiation than the optical light they reflect, and astronomers in the past have used infrared surveys like the Wide-field Infrared Explorer (WISE) to search, but without success.

The study has been advanced by a team of researchers led by Sigurd Naess of the Institute of Theoretical Astrophysics at the University of Oslo, as a part of the Atacama Cosmology Telescope (ACT) collaboration led by Principal Investigator, Professor Suzanne Staggs of Princeton University. CfA astrophysicist Benjamin Schmitt was a member of the team to lead the design, integration, and field operation of ACT’s millimeter-wavelength, polarization-sensitive camera – called ACTPol – which took the data central to the Planet 9 study, working with Professor Mark Devlin at the University of Pennsylvania.

Although ACT was designed to study the cosmic microwave background radiation, its relatively high angular resolution and sensitivity makes it suitable for this type of search. The astronomers scanned about 87% of the sky accessible from the southern hemisphere over a six year period, and then processed the millimeter images with a variety of techniques including binning and stacking methods that might uncover faint sources but at the expense of losing positional information.

Their search found many tentative candidate sources (about 3500 of them) but none could be confirmed, and there were no statistically significant detections. The scientists, however, were able to exclude with 95% confidence a Planet 9 with the above-estimated properties within the surveyed area, results that are generally consistent with other null searches for Planet 9.

The results cover only about 10-20% of the possibilities, but other sensitive millimeter facilities are coming online and should be able to complete this search for Planet 9 as hypothesized. Reference: “The Atacama Cosmology Telescope: A Search for Planet 9,” Sigurd Naess et al.

Is there any 10 planets?

There are eight planets in the solar system : Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Why Pluto is not a planet?

In August 2006 the International Astronomical Union (IAU) downgraded the status of Pluto to that of “dwarf planet.” This means that from now on only the rocky worlds of the inner Solar System and the gas giants of the outer system will be designated as planets.

The “inner Solar System” is the region of space that is smaller than the radius of Jupiter’s orbit around the sun. It contains the asteroid belt as well as the terrestrial planets, Mercury, Venus, Earth, and Mars. The “gas giants” of course are Jupiter, Saturn, Neptune, and Uranus. So now we have eight planets instead of the nine we used to have.

What is a Dwarf Planet? A “dwarf planet,” as defined by the IAU, is a celestial body in direct orbit of the Sun that is massive enough that its shape is controlled by gravitational forces rather than mechanical forces (and is thus ellipsoid in shape), but has not cleared its neighboring region of other objects,

  1. It is in orbit around the Sun.
  2. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape).
  3. It has “cleared the neighborhood” around its orbit.

Pluto meets only two of these criteria, losing out on the third. In all the billions of years it has lived there, it has not managed to clear its neighborhood. You may wonder what that means, “not clearing its neighboring region of other objects?” Sounds like a minesweeper in space! This means that the planet has become gravitationally dominant – there are no other bodies of comparable size other than its own satellites or those otherwise under its gravitational influence, in its vicinity in space.

  1. So any large body that does not meet these criteria is now classed as a “dwarf planet,” and that includes Pluto, which shares its orbital neighborhood with Kuiper belt objects such as the plutinos.
  2. History of Pluto The object formerly known as the planet Pluto was discovered on February 18, 1930 at the Lowell Observatory in Flagstaff, Arizona, by astronomer Clyde W.

Tombaugh, with contributions from William H. Pickering. This period in astronomy was one of intense planet hunting, and Pickering was a prolific planet predictor. In 1906, Percival Lowell, a wealthy Bostonian who had founded the Lowell Observatory in Flagstaff, Arizona in 1894, started an extensive project in search of a possible ninth planet, which he termed “Planet X.” By 1909, Lowell and Pickering had suggested several possible celestial coordinates for such a planet.

  • Lowell and his observatory conducted the search until his death in 1916, to no avail.
  • Unknown to Lowell, on March 19, 1915, his observatory had captured two faint images of Pluto, but they were not recognized for what they were.
  • Lowell was not the first to unknowingly photograph Pluto.
  • There are sixteen known pre-discoveries, with the oldest being made by the Yerkes Observatory on August 20, 1909.
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The search for Planet X did not resume until 1929, when the job was handed to Clyde Tombaugh, a 23-year-old Kansan who had just arrived at the Lowell Observatory. Tombaugh’s task was to systematically image the night sky in pairs of photographs taken two weeks apart, then examine each pair and determine whether any objects had shifted position.

Using a machine called a blink comparator, he rapidly shifted back and forth between views of each of the plates to create the illusion of movement of any objects that had changed position or appearance between photographs. On February 18, 1930, after nearly a year of searching, Tombaugh discovered a possible moving object on photographic plates taken on January 23 and January 29 of that year.

After the observatory obtained further confirmatory photographs, news of the discovery was telegraphed to the Harvard College Observatory on March 13, 1930. The discovery made headlines across the globe. The Lowell Observatory, which had the right to name the new object, received over 1,000 suggestions from all over the world; the name Pluto was proposed by Venetia Burney, an eleven-year-old schoolgirl in Oxford, England.

Venetia was interested in classical mythology as well as astronomy, and considered the name for the god of the underworld appropriate for such a presumably dark and cold world. She suggested it in a conversation with her grandfather Falconer Madan, a former librarian at the University of Oxford’s Bodleian Library.

Madan passed the name to Professor Herbert Hall Turner, who then cabled it to colleagues in the United States. Pluto officially became Pluto on March 24, 1930. The name was announced on May 1, 1930, and Venetia received five pounds (£5) as a reward.

Further Reading
  • Boyle, Alan. The case for Pluto: how a little planet made a big difference, Hoboken, N.J, John Wiley & Sons, c2010.258 p.
  • Doressoundiram, Alain, and Emmanuel Lellouch. At the edge of the solar system: icy new worlds unveiled,, Berlin, New York, Springer Verlag; Chichester, U.K,: Published in association with Praxis, c2010.205 p. Original French edition: Aux confin de système solaire
  • Hoyt, William Graves.W.H. Pickering’s planetary predictions and the discovery of Pluto. Isis, v.67, Dec.1976: 551-564.
  • Pickering, W.H. Trans-Neptunian Planet. Popular astronomy, v,38, June-July1930: 341-344.
  • Putnam, Roger Lowell, and V.M. Slipher. Searching out Pluto, Lowell’s trans-Neptunian planet X. Scientific monthly, v.34, Jan.1932: 5-21.
  • Tyson, Neil deGrasse. The Pluto files: the rise and fall of America’s favorite planet. New York, W.W. Norton, c2009.194 p.

For more print resources. Search on “Kuiper Belt” “Pluto (dwarf planet),” “Planets,” or “Solar System” in the Library of Congress Online Catalog, Solar System Montage – Graphic from the Nasa Website. Full description, Pluto and Its Moons: Charon, Nix, and Hydra. A pair of small moons that NASA’s Hubble Space Telescope discovered orbiting Pluto now have official names: Nix and Hydra. Photo: Nasa Website. Pluto: Overview, Pluto is a member of a group of objects that orbit in a disc-like zone beyond the orbit of Neptune called the Kuiper Belt, Kuiper Belt Sizes, Graphic from the Nasa Website. Percival Lowell, half-length portrait, facing slightly left. Prints and Photographs Online Catalog, Library of Congress. Pluto’s Symbol. The symbol for Pluto is a monogram made up of the P and L in Pluto and also the initials of the astronomer, Percival Lowell, who predicted its discovery. Image credit: Lunar and Planetary Institute. Text from NASA Website. Mural of Astronomy by Walter Shirlaw. Library of Congress Thomas Jefferson Building, Washington, D.C. From the Prints and Photographs Online Catalog.

Why does Planet 9 exist?

Naming – Planet Nine does not have an official name and will not receive one unless its existence is confirmed via imaging. Only two planets, Uranus and Neptune, have been discovered in the Solar System during recorded history. However, many minor planets, including dwarf planets such as Pluto, asteroids, and comets have been discovered and named.

Consequently, there is a well-established process for naming newly discovered Solar System objects. If Planet Nine is observed, the International Astronomical Union will certify a name, with priority usually given to a name proposed by its discoverers. It is likely to be a name chosen from Roman or Greek mythology,

In their original article, Batygin and Brown simply referred to the object as “perturber”, and only in later press releases did they use “Planet Nine”. They have also used the names ” Jehoshaphat ” and “George” (a reference to William Herschel ‘s proposed name for Uranus ) for Planet Nine.

Brown has stated: “We actually call it Phattie when we’re just talking to each other.” In 2018, Batygin has also informally suggested, based on a petition on, to name the planet after singer David Bowie, and to name any potential moons of the planet after characters from Bowie’s song catalogue, such as Ziggy Stardust or Starman,

Jokes have been made connecting “Planet Nine” to Ed Wood ‘s 1959 science-fiction horror film Plan 9 from Outer Space, In connection with the Planet Nine hypothesis, the film title recently found its way into academic discourse. In 2016, an article titled Planet Nine from Outer Space about the hypothesized planet in the outer region of the Solar System was published in Scientific American,

Several conference talks since then have used the same word play, as did a lecture by Mike Brown given in 2019. Persephone, the wife of the deity Pluto, had been a popular name commonly used in science fiction for a planet beyond Neptune (see Fictional planets of the Solar System ). However, it is unlikely that Planet Nine or any other conjectured planet beyond Neptune will be given the name Persephone once its existence is confirmed, as it is already the name for asteroid 399 Persephone,

In 2017, physicist Lorenzo Iorio suggested to name the hypothetical planet as ″Telisto″, from the ancient Greek word “τήλιστος” for “farthest” or “most remote”. In 2018, planetary scientist Alan Stern objected to the name Planet Nine, saying, “It is an effort to erase Clyde Tombaugh ‘s legacy and it’s frankly insulting”, suggesting the name Planet X until its discovery.

He signed a statement with 34 other scientists saying, “We further believe the use of this term should be discontinued in favor of culturally and taxonomically neutral terms for such planets, such as Planet X, Planet Next, or Giant Planet Five.” According to Brown, ” ‘ Planet X ‘ is not a generic reference to some unknown planet, but a specific prediction of Lowell’s which led to the (accidental) discovery of Pluto.

Our prediction is not related to this prediction.”

Why is there only 8 planets instead of 9?

There were nine planets in the solar system, Which are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Now we have only eight planets as pluto is excluded. –

What is the 9th planet name?

Pluto was once considered the ninth planet in the solar system. It was demoted in 2006. Jump to: Pluto FAQs answered by an expert.

When did we have 9 planets?

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.

Is there a 9th or 10th planet?

Answer: – There is no known Planet X or 10th planet in our solar system. Scientists have been looking for about a hundred years. It was believed that such a planet was required to explain the orbital characteristics of the outer planets Uranus and Neptune.

Many searches have been performed and, to date, no evidence of such a planet has emerged. In addition, better information about the masses of outer planets has also now shown that no other planets are necessary to explain the planetary orbits. You can get a good historical account of the searches for “Planet X” at: Read an update on the new objects being found in our solar system which are not being classified as planets! Yet, there are new planets being discovered! However, any new planets you may hear, or have heard, about being discovered are around other stars, not our Sun! You can read all about the search for, and discovery of, planets around other stars at or get a very comprehensive discussion at How will these new planets be named? The planets that are being found around other stars are given scientific catalog names (like SV168) and not the names of people (real or mythological ).

All objects, whether moons or asteroids or planets, are named by the International Astronomical Union according to strict guidelines. You can read about this at Thanks for asking! The StarChild site is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr.

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Is there 21 planets?

A planet is any relatively large natural body that revolves in an orbit around the Sun or around some other star and that is not radiating energy from internal nuclear fusion reactions. In addition to the above description, some scientists impose additional constraints regarding characteristics such as size, shape, or mass.

Do we have 14 planets?

There are more planets than stars in our galaxy. The current count orbiting our star : eight, The inner, rocky planets are Mercury, Venus, Earth, and Mars, NASA’s newest rover — Perseverance — landed on Mars on Feb.18, 2021. The outer planets are gas giants Jupiter and Saturn and ice giants Uranus and Neptune,

Beyond Neptune, a newer class of smaller worlds called dwarf planets reign, including longtime favorite Pluto, Thousands more planets have been discovered beyond our solar system. Scientists call them exoplanets (exo means “from outside”). Planets of our Solar System What is a Dwarf Planet? The key difference between a planet and a dwarf planet is the kinds of objects that share its orbit around the Sun.

Pluto, for example, has not cleared its orbit of similar objects while Earth or Jupiter have no similarly-sized worlds on the same path around the Sun. Like planets, dwarf planets are generally round (Haumea looks like an overinflated football) and orbit the Sun.

There are likely thousands of dwarf planets waiting to be discovered beyond Neptune. The five best-known dwarf planets are Ceres, Pluto, Makemake, Haumea, and Eris, Except for Ceres, which lies in the main asteroid belt, these small worlds are located in the Kuiper Belt, They’re considered dwarfs because they are massive, round, and orbit the Sun, but haven’t cleared their orbital path.

Real-Time, Interactive Solar System

Do we have 13 planets?

For now, there are eight classical planets and five dwarf planets, making thirteen!

Is Uranus a planet anymore?

Uranus is the seventh planet from the Sun, and has the third-largest diameter in our solar system. It was the first planet found with the aid of a telescope, Uranus was discovered in 1781 by astronomer William Herschel, although he originally thought it was either a comet or a star. It was two years later that the object was universally accepted as a new planet, in part because of observations by astronomer Johann Elert Bode. Herschel tried unsuccessfully to name his discovery Georgium Sidus after King George III. Instead, the scientific community accepted Bode’s suggestion to name it Uranus, the Greek god of the sky, as suggested by Bode.​ Ten Things to Know About Uranus

Did NASA declare Pluto a planet again?

Jim Bridenstine, the NASA administrator appointed by US President Donald Trump, has declared Pluto to be a planet again. – The new NASA administrator appointed by US President Donald Trump, Jim Bridenstine, has declared Pluto to be a planet again. The most surprising factor is that Bridenstine didn’t say this based on any new research but just because that is “the way I (he) learned it”.

  • Cory Reppenhagen, a journalist at 9NEWS, shared a 15-minute video clip on Twitter, where he is seen saying: “Just so you know, in my view, Pluto is a planet, and you can write that the NASA administrator declared Pluto a planet once again.” “I’m sticking by that.
  • It’s the way I learned it, and I’m committed to it,” he added.

“Pluto’s status as a planet has sparked the human imagination for decades. Now is not the time to downgrade Pluto’s status,” Jim Bridenstine said. Bridenstine was speaking at a FIRST robotics event in Colorado. My favorite soundbyte of the day that probably won’t make it to TV.

What is the hottest planet?

Venus is the second planet from the Sun and is Earth’s closest planetary neighbor. It’s one of the four inner, terrestrial (or rocky) planets, and it’s often called Earth’s twin because it’s similar in size and density. These are not identical twins, however – there are radical differences between the two worlds. Venus has a thick, toxic atmosphere filled with carbon dioxide and it’s perpetually shrouded in thick, yellowish clouds of sulfuric acid that trap heat, causing a runaway greenhouse effect. It’s the hottest planet in our solar system, even though Mercury is closer to the Sun.

Surface temperatures on Venus are about 900 degrees Fahrenheit (475 degrees Celsius) – hot enough to melt lead. The surface is a rusty color and it’s peppered with intensely crunched mountains and thousands of large volcanoes. Scientists think it’s possible some volcanoes are still active. Venus has crushing air pressure at its surface – more than 90 times that of Earth – similar to the pressure you’d encounter a mile below the ocean on Earth.

Another big difference from Earth – Venus rotates on its axis backward, compared to most of the other planets in the solar system. This means that, on Venus, the Sun rises in the west and sets in the east, opposite to what we experience on Earth. (It’s not the only planet in our solar system with such an oddball rotation – Uranus spins on its side,) Venus was the first planet to be explored by a spacecraft – NASA’s Mariner 2 successfully flew by and scanned the cloud-covered world on Dec.14, 1962.

  1. Since then, numerous spacecraft from the U.S.
  2. And other space agencies have explored Venus, including NASA’s Magellan, which mapped the planet’s surface with radar.
  3. Soviet spacecraft made the most successful landings on the surface of Venus to date, but they didn’t survive long due to the extreme heat and crushing pressure.

An American probe, one of NASA’s Pioneer Venus Multiprobes, survived for about an hour after impacting the surface in 1978. More recent Venus missions include ESA’s Venus Express (which orbited from 2006 until 2016) and Japan’s Akatsuki Venus Climate Orbiter (orbiting since 2016). As Parker Solar Probe flew by Venus in February 2021, its WISPR instrument captured these images, strung into a video, showing the nightside surface of the planet. Credit: NASA/APL/NRL In June 2021, three new missions to Venus were announced. NASA announced two new missions, and ESA announced one :

VERITAS : NASA’s VERITAS, or Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy, will be the first NASA spacecraft to explore Venus since the 1990s. The spacecraft will launch no earlier than December 2027. It will orbit Venus, gathering data to reveal how the paths of Venus and Earth diverged, and how Venus lost its potential to be a habitable world. DAVINCI : NASA’s DAVINCI mission will launch in the late 2020s. After exploring the top of Venus’s atmosphere, DAVINCI will drop a probe to the surface. On its hour-long descent, the probe will take thousands of measurements and snap up-close images of the surface. The probe may not survive the landing, but if it does, it could provide several minutes of bonus science. EnVision : ESA has selected EnVision to make detailed observations of Venus. As a key partner in the mission, NASA is providing the Synthetic Aperture Radar, called VenSAR, to make high-resolution measurements of the planet’s surface features.

Ten Things to Know About Venus

Is there a ghost planet?

Planet 9: the hidden planet potentially lurking in our Solar System In the far reaches of our Solar System, there may lie a giant, mysterious planet that is yet to be discovered. Some astronomers are convinced that it exists, but if so, why haven’t we found it yet? A representation of what hypothetical Planet 9 may look like.05/06/2022 14:00 4 min We know more about the Solar System now than we ever have done before, yet an enduring mystery prevails, one which carries so much intrigue it could slot neatly into the plot of a science fiction movie.

Is Planet 9 a black hole?

Planet Nine: Scientists Think They Can Find the Missing Planet 9

, the hypothetical ninth planet, may be orbiting out past Neptune, in or just past the Kuiper Belt.A new suggests it’s possible that—if it exists—Planet Nine may have collected some moons.While the dark planet gives off no signals we can detect, observing the heat from those moons may be a way to finally spot Planet Nine.

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There’s been a hypothesis floating around for a few years that there might be a ninth planet in our Solar System—and it’s not, is unnamed, unconfirmed, and unknown. We haven’t been able to detect it, and we don’t even know for sure that if we did spot it, it would even be a planet. It might be a special kind of, or be made entirely of dark matter. But whatever it is—if it exists—we want to find it. It would explain a lot of the odd behavior astronomers detect in objects out past in the Kuiper belt. And according to a new, the way to find it might be through the moons it could have scooped up over time.

What is ghost planet?

Ratchet: What the.where is everyone? Clank: I tried to tell you, Ratchet. The database said this planet was deserted ages ago! What you get when a Ghost Town is global in scale. Another planet or Another Dimension that, by the time we get to see it, has been left in ruins for a long, long time,

There are signs here and there that this world once boasted a civilization, maybe even a great civilization, but all that’s left now are a few decaying remnants. The world need not be entirely barren of life, but, generally speaking, if there are enough of the original denizens left to form a town or city, it’s not a Ghost Planet.

Please keep in mind, a Ghost Planet should not be a future version of our own Earth (or at least not explicitly so). A desolated future Earth would go under Earth That Was, Only alien worlds which have gone through their own Armageddon (somewhere between Class 2 and Class 5 on the Apocalypse How scale) need apply.

Will all 8 planets ever align?

Is an 8-Planet Alignment Possible? While there are certainly headlines about it from time to time, full planetary alignment is actually virtually impossible, and even seeing all the planets on the same side of the sun in the sky is incredibly uncommon.

Which planet is 9 times bigger than Earth?

Size and Distance – With a radius of 36,183.7 miles (58,232 kilometers), Saturn is 9 times wider than Earth. If Earth were the size of a nickel, Saturn would be about as big as a volleyball. From an average distance of 886 million miles (1.4 billion kilometers), Saturn is 9.5 astronomical units away from the Sun.

Is Planet 9 a dwarf planet?

What is Planet 9? – Planet Nine is a hypothetical giant planet that might be orbiting the Sun somewhere beyond Pluto. Its presence is one possible explanation for the weird way a handful of small icy objects in the outskirts of the solar system seem to cluster into very similar orbits.

These objects are all in the Kuiper Belt, the same region of the Solar System that contains Pluto. These objects — including the dwarf planet Sedna — all loop around the Sun in long, narrow elliptical orbits. They’re all tilted at about the same slight angle relative to most of the Solar System, and they all make their closest pass to the Sun in roughly the same sector of the Solar System.

It looks as if these small objects’ orbits are stretched and tilted by the gravity of something much bigger: an unseen planet. These objects are believed to have been flung into their weird orbits by Planet Nine. Caltech In 2016, Caltech astronomers Michael Brown and Konstantin Batygin published the results of their computer models, which suggested that a planet about the mass of Neptune, orbiting unseen about 20 times further from the Sun than Neptune, could provide the gravitational nudge that explains the cluster of small Kuiper Belt objects.

Is there a 9th or 10th planet?

Answer: – There is no known Planet X or 10th planet in our solar system. Scientists have been looking for about a hundred years. It was believed that such a planet was required to explain the orbital characteristics of the outer planets Uranus and Neptune.

  • Many searches have been performed and, to date, no evidence of such a planet has emerged.
  • In addition, better information about the masses of outer planets has also now shown that no other planets are necessary to explain the planetary orbits.
  • You can get a good historical account of the searches for “Planet X” at: Read an update on the new objects being found in our solar system which are not being classified as planets! Yet, there are new planets being discovered! However, any new planets you may hear, or have heard, about being discovered are around other stars, not our Sun! You can read all about the search for, and discovery of, planets around other stars at or get a very comprehensive discussion at How will these new planets be named? The planets that are being found around other stars are given scientific catalog names (like SV168) and not the names of people (real or mythological ).

All objects, whether moons or asteroids or planets, are named by the International Astronomical Union according to strict guidelines. You can read about this at Thanks for asking! The StarChild site is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr.

Which was the 9th planet?

Pluto was once considered the ninth planet in the solar system. It was demoted in 2006. Jump to: Pluto FAQs answered by an expert.

What is the 8th planet called?

Eighth Wanderer – 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).3

What are the 9 planets for kids?

Did you know? –

  • The Sun is 93 million miles from the Earth. The light from the Sun only takes 8 minutes to travel to the Earth, but it would take Usain Bolt – the fastest man on Earth – 450 years to run from the Sun to the Earth.
  • The Earth travels around the Sun in a loop that is shaped a bit like an oval. We call this the Earth’s orbit,
  • The Earth is always spinning around – sometimes from where you stand on the Earth you can see the Sun (this is the daytime) and sometimes the part of the Earth where you are is facing away from the Sun so it is dark (this is the nightime). It takes 24 hours for the Earth to spin all the way around, and we call this a day. Find out more about night and day,
  • There are eight planets that orbit around the Sun. In order, going from the closest planet to the Sun, to the one that is farthest away, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
  • All of the planets and the Sun are round, like balls.
  • There is a lot of difference between the planets. Some planets like Earth are made of rock, and some like Jupiter are made of gas. The hottest planet is Venus where the average temperature is 460°C, and the coldest is Uranus, which is -220°C.
  • Mars is sometimes the called ‘the red planet’ because the rocks that it is made from are red. It is the closest planet to Earth, and is slightly smaller than Earth.
  • The biggest planet is Jupiter. Jupiter is made of gas and is so big that you could fit 1,321 planets the size of Earth inside it. There is even a storm on Jupiter that is bigger than Earth – this storm has been blowing for hundreds of years and is called the ‘Great Red Spot’.
  • Saturn is famous for having rings of small pieces of ice and dust around it. Like Jupiter, it is made of gas and is much bigger than Earth.
  • The Moon is a ball of rock that orbits around the Earth, in the same way that the Earth orbits around the Sun. It is much smaller than the Earth and takes 28 days to complete one orbit. The Moon is 239,000 miles away and is the only place in the Solar System that man has travelled to apart from Earth. Find out more about human space exploration,
  • Other planets have moons too. Jupiter has at least 66 of them!