A team of astronomers has discovered the farthest object within the solar system. It is a dwarf planet that is the first one that has been observed more than 100 times the distance between the Sun and the Earth. If the average separation between these two bodies is 150 million kilometers – an astronomical unit – the new object is 120 times farther away, some 18,000,000,000 kilometers. Until now, the most distant object known was Eris, at 96 astronomical units, much more distant than Pluto, at 39.5.
The Center for Minor Planets of the International Astronomical Union today announced the existence of this body. Its official name is difficult to remember -2018 VG18- but its discoverers nicknamed it Farout, which in English means both distant and eccentric, two hallmarks of this object in the confines of the solar system.
The Americans Scott Sheppard, of the Carnegie Institution, David Tholen, of the University of Hawaii, and Chad Trujillo, of the University of Northern Arizona, have discovered the new planet by chance. What they were really looking for is a planet several times greater than Earth that would be the ninth known after Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Although for now it has not been possible to observe this planet X, the team of astronomers believes that exists because of the alleged influence exerted by its gravity on other bodies of smaller size, such as The Elf, a dwarf planet to 80 astronomical units discovered last October.
On November 10, the Japanese Subaru telescope on the top of the Hawaiian volcano Mauna Kea captured the first image of the dwarf planet. The observation was confirmed by another telescope at the Las Campanas Observatory in Chile, this same month.
"2018 VG18 is farther away and moves more slowly than any other object in the solar system, so it will take years to determine its orbit", explains Sheppard in a press release. The planet was found "at a point in the sky close to that of other of the farthest known bodies, so it may have an orbit similar to the rest. The similarities in the orbits of many of these objects is the basis for the possible existence of a massive planet with several hundred astronomical units that influences their orbits at a distance, "the astronomer points out.
The new planet takes more than 1,000 years to make a return to the Sun. By its brightness they calculate that it is about 500 kilometers in diameter and a pink color that usually betrays the presence of a large amount of ice.
The Spanish astronomer Guillem Anglada-Escudé he believes that more dwarf planets, even farther away, will probably be discovered. "There have to be dozens of them and when there are enough you can have a better idea of the dynamics of these distant orbits, which is a fossil record of the formation of the solar system and should be fine-tuning the existence or absence of planet X that, if the simulations are correct, it could be 500 astronomical units, "he says.