Despite many attempts, astronomers have come up empty in the search for Planet 9. The 6-meter Atacama Cosmology Telescope in Chile has found thousands of candidate sources but couldn’t confirm any of them. It has also seen thousands of stars in the Kuiper Belt – the outermost region of our solar system – but no planets. In addition, scientists have observed that the heliosphere – the teardrop-shaped region of space that surrounds the sun – is the limit of the search for Planet 9.
Scientists have discovered that Pluto is not the only body orbiting the sun. The distant solar system has thousands of icy bodies that are not even close to the Earth’s surface. It begins at the orbit of Neptune and spans approximately 30 astronomical units. Pluto was discovered in the inner reaches of the solar system, where it shares its orbit with Kuiper belt objects. Its size is approximately a third of that of the moon.
Scientists have found a number of moons orbiting Pluto, including Kerberos, the fourth moon discovered by Hubble. Kerberos is double-lobed, with a larger lobe measuring five miles (8 km) in diameter and a smaller lobe measuring just three miles (4 km) in diameter. In total, Pluto has five moons, the smallest of which is about 3 miles (4 km) across. The fifth moon, called Styx, is estimated to be about six miles (10 km) across. The discovery of Styx has fuelled debates regarding Pluto’s status.
While we cannot see the atmosphere on Pluto, we do know that it is predominantly composed of nitrogen and a thin layer of water. There are also traces of methane and carbon monoxide, and both substances are most abundant on the anti-Charon face of the planet. Pluto’s surface is also unusually varied. Some parts of the planet are as bright as snow while others are dark as charcoal.
The resolution to include Pluto in the list of planets was controversial. While the resolution was based on old definitions, it was a positive step forward. The new definition allows for more exploration of space and its moons. This resolution will help us make better use of this incredible resource. But before we do that, let’s take a look at how Pluto is classified. Its status has been up for debate for decades.
The discovery of Pluto happened in 1930. The Lowell Observatory in Massachusetts had the right to name the new object. Over 1,000 people suggested names for the new object. Ultimately, the name “Pluto” was selected by Venetia Burney, an 11-year-old girl from Oxford, England. Her suggestion was passed on to her grandfather, Professor Percival Lowell. This suggestion was eventually accepted by Professor Herbert Hall Turner, who cabled the name to colleagues in the United States. The new planet was officially named on March 24, 1930.
The surface of Pluto is very cold, a few thousand degrees Celsius above absolute zero. Water is practically rock-like at this temperature, but scientists believe that the interior of Pluto may be warmer than its surface. There may be a liquid ocean inside. With a radius of seventy-nine miles, Pluto is about the size of a popcorn kernel. It orbits the sun 300 to 1,000 times farther from the sun than Neptune.
The image of Pluto taken by New Horizons shows that the atmosphere is blue, and its limbs show a mountainous zone. X-rays produced by Pluto’s interaction with the solar wind also have the same effect on its composition. As a mutually tidally-locked system, Pluto has no way of separating itself from its sister planets. Its icy world has no way to stop the moon from orbiting the planet, which is why Pluto and Charon are both quite similar.
Despite the fact that Pluto was once considered the ninth planet, many scientists think it is a dwarf planet. This body resides in the Kuiper Belt, which is the shadowy zone that lies beyond Neptune’s orbit. The Kuiper Belt is thought to contain hundreds of thousands of icy and rocky bodies, including more than a trillion comets. This phenomenon could result in a number of Earth-like bodies orbiting Pluto.
In addition to Pluto, the other nine planets of the solar system also include the dwarf planet Ceres. Pluto is the ninth largest object in the solar system, with a diameter of 590 miles. Pluto’s orbit is so far from the sun that it is nearly as large as Earth’s. A number of asteroids have orbits that bring them closer to Earth and other inner planets.
Ceres is a small, icy world in our solar system. It resembles Europa and Enceladus in many ways. It is mostly rocky, with a thin layer of water ice in its mantle. Researchers believe that Ceres may be more than 25% water, and it may be capable of supporting life. Other features of Ceres include bright spots, craters, and cryovolcano features.
In August 2006, the International Astronomical Union classified Ceres as a dwarf planet. The space probe Dawn studied Ceres from March 2015 to November 2018. In November 2018, NASA discovered that Ceres is spewing water, a sign that it has been hit by a meteor. These bright spots on Ceres are actually reflective salts. They have been formed by briny water that percolated upward through the fractures left by a crater 20 million years ago. Micrometeorite impacts have not darkened these salty regions, which are believed to be only two million years old.
While it is not a planet, Ceres is a dwarf planet and is the largest asteroid belt body. It contains approximately a third of the mass of the asteroids in the solar system. It is also the only dwarf planet without a natural satellite and ring system. Its discovery came about after astronomers noticed a gap in the asteroid belt between Mars and Jupiter, and they assumed that this space rock held a planet that was missing. The asteroid belt is full of objects larger than Ceres, and the two bodies are separated by more than one-third of the planet’s mass. In 2006, the astronomers confirmed that Ceres was a dwarf planet, and it has now been given the status of a dwarf planet.
Ceres is a water-rich celestial body that takes about 1,682 Earth days to complete one orbit around the sun. Its day length is one of the shortest in the solar system. Its axis of rotation is tilted four degrees compared to the plane of its orbit around the Sun. Ceres does not have an atmosphere, so light can’t travel to its surface. It also doesn’t have any rings or moons.
Observations of Ceres’ surface have yielded intriguing insights into the origins of the solar system. Its icy salt deposits are the most likely explanation for Ceres’ bright regions. The icy water ice that forms inside Ceres’ surface vaporizes when the asteroid rotates into the sunlight, resulting in the formation of haze clouds.
Unlike most of the other planets, Ceres doesn’t have an atmosphere. Its surface contains small amounts of water vapor, and this is likely a sign of an outgassing or cryovolcano on Ceres. Ceres’s mantle is 100 kilometers thick, and it contains an estimated 200 million cubic kilometers of water. That’s enough water for Earth.
Researchers have studied the surface features around recently formed craters on Ceres for five years. They have concluded that Ceres may have an underground body of briny liquid. Variations in the planet’s gravitational field support this idea. This liquid could stretch hundreds of miles underneath the surface ice, and reach depths of 25 miles. Future missions could confirm or disprove this theory.
The surface of Ceres is covered with numerous small, young craters, and has none larger than 175 miles in diameter. Because Ceres is in the asteroid belt, it would have been hit by many large celestial objects over the course of its history. This lack of impact damage may be due to the icy terrain below the surface. There is also a possibility that large craters were covered by ice volcanoes.
The weight of astronauts on Ceres would be significantly less than the actual mass of the body, due to the low gravity. The low gravity on Ceres means that astronauts will have much lower weight than their actual mass. That is why Ceres has been considered a dwarf planet. A few other objects in its neighborhood have this status. So, while Ceres does have some similarities to Vesta, it falls into the second category of dwarf planets.
Though small, Ceres is too dim to be seen with the naked eye. It has an apparent magnitude of 6.7 to 9.3 and only peaks at opposition once every fifteen to sixteen months. The surface features of Ceres are barely visible even with binoculars. A robotic spacecraft called Dawn was sent to orbit Ceres in 2010.