Pluto offered to return the status of the planet
NASA employees, headed by Alan stern, principal investigator of the mission “New horizons”, published an article excerpt, which suggested that the International astronomical Union to revisit the definition of a planet.
It would allow Pluto to regain the status that it lost in 2006. Full article will be presented in March at a conference on the moon and planets.
With the development of science ideas about planets have changed many times: for example, the Ptolemaic scientists of the era believed that planets are major celestial bodies that revolve around the Earth in circular orbit, and later it turned out that in fact they rotate around the Sun and their orbits are not circular but elliptical. After the discovery of the first extrasolar planets that are around other stars, scientists had to create an official definition of the term. In February 2003, the working group on ekzoplaneta of the International astronomical Union declared that the planet is considered a celestial body with a mass below progranichnoe mass start thermonuclear fusion of deuterium, which orbits a star or its remnants. The minimum mass and/or size needed in order to consider the object extrasolar planet was supposed to be similar to those that occur in the Solar system.
The last official definition of the term was given International astronomical Union in 2006. During the conference in Prague, the researchers decided that the planet must meet three criteria: to revolve in an orbit around the Sun, have sufficient gravity to make a sphere, and to clear the neighborhood of its orbit.
According to the new classification of Pluto was excluded from the number of planets and with Erys and Ceres (and later Makemake and Haumea) are listed as among the dwarf planets, which are not able to see the area around its orbit of space debris
This “innovation” has caused controversy and criticism from the scientific community.
Researchers from NASA have published a Manifesto in which they propose to revise the definition of a planet. The work States that the planet should be considered subsignal body mass, which never happened of fusion reaction and which has sufficient gravity to make a spherical shape. While the orbital parameters of the object proposed not to consider.
The authors of the Manifesto believe that the present definition of a planet has several significant disadvantages. First, it can not be attributed to the exoplanet, and the wandering of the planets among the planets. Second, any planet in the Solar system, according to scientists, could not fully clear their orbits of small celestial bodies, like meteoroids, will still be to cross them. Thirdly, the ability to remove space debris depends on the distance to the Sun. According to experts NASA, if Land is put on Neptune, it will not be able to clear its orbit, therefore, will not be considered a planet. On the other hand, under the proposed definition researchers get as and larger moons such as Charon or the Moon.
The reaction of the International astronomical Union on the manifest is not reported. However, if it is approved, Pluto will have to regain their status as planets. “You must listen to the scientists, who are familiar with this topic. When we see objects of Pluto, we don’t know how else to call them,” said Alan stern, in an interview with Business Insider.