Q Why is it in News ?
A A new study’s “treasure map” suggests that a planet several times more massive than Earth could be hiding in our solar system, camouflaged by the bright strip of stars that make up the Milky Way.
Q What is Planet 9 ?
- Planet Nine is a hypothetical planet in the outer region of the Solar System.
- Its gravitational effects could explain the unlikely clustering of orbits for a group of extreme trans-Neptunian objects (ETNOs), bodies beyond Neptune that orbit the Sun at distances averaging more than 250 times that of the Earth.
- Based on earlier considerations, this hypothetical super-Earth-sized planet would have had a predicted mass of five to ten times that of the Earth, and an elongated orbit 400 to 800 times as far from the Sun as the Earth.
Q Why is there Curiosity for the ninth Planet ?
- In August 2006, the International Astronomical Union broke several hearts when it announced that it had reclassified Pluto as a dwarf planet. ‘
- The decision was based on Pluto’s size and the fact that it resides within a zone of other similarly-sized objects.
Q Is everyone convinced that Planet Nine exists?
- Researchers from across the globe have carried out several studies on Planet Nine and there are several theories about it, including one that stated Planet Nine could in fact be a black hole.
- Another research has argued that the unknown object causing anomalous orbits of the trans-Neptunian objects could be a primordial black hole.
- Yet another study noted that a trans-Neptunian object called 2015 BP519 had an unusual trajectory because it was affected by Planet Nine’s strong gravity.
Q What is a Dwarf Planet ?
- A dwarf planet is a small planetary-mass object that is in direct orbit of the Sun – something smaller than any of the eight classical planets, but still a world in its own right.
- As of today, there are officially five dwarf planets in our Solar System.
- The most famous is Pluto, downgraded from the status of a planet in 2006.
- The other four, in order of size, are Eris, Makemake, Haumea and Ceres. The sixth claimant for a dwarf planet is Hygiea, which so far has been taken to be an asteroid.
- These four criteria are that the body orbits around the Sun, it is not a moon, has not cleared the neighborhood around its orbit, and has enough mass for its gravity to pull it into a roughly spherical shape.