Is there a ‘hidden’ Earth-like planet? – 09/05/2023 – Science

Finding exoplanets (planets outside our solar system) is no easy task. Still, 5,502 have been discovered since 1992, when the first one was found.

Now, a team of astronomers ventures the unthinkable: the possibility that there is an Earth-like planet yet to be discovered in our own solar system.

But discovering celestial objects in our own solar system is a little more complicated and involves finding them by observing the movement of other stars. Neptune, for example, was discovered after astronomer and mathematician Urbain Le Verrier identified a difference between the observed orbit of Uranus and the way it was predicted by Newtonian physics.

This led him to suspect that the alteration of the orbit was caused by the gravitational influence of a planet located beyond Uranus. Said and done: when the German astronomer Johann Gottfried Galle went to check the place where the new planet should be, there was Neptune.

Finally the famous ‘Planet 9’?

For years, astronomers have speculated about the existence of another yet-to-be-discovered world in our solar system, commonly known as “Planet 9”. Now, Japanese scientists have gone even further, suggesting that there is another “Earth-like” planet to be discovered – and much closer to us.

In a new paper published in The Astronomical Journal, astrophysicists Patryk Sofia Lykawka of Kindai University in Japan and Takashi Ito of the Japanese National Astronomical Observatory analyze the motion of celestial objects in the Kuiper Belt.

Through simulations, the team concluded that a planet the size of Earth could be behind the unusual movements of stars beyond Neptune’s orbit.

According to the researchers, the planet would have a mass between 1.5 and 3 times that of Earth and an orbit inclined at about 30 degrees.

They say they believe this new planet lurks in the Kuiper Belt, a circumstellar ring that extends just beyond Neptune’s orbit. This one, called the Kuiper Belt Planet (KBP), would be at a distance of up to 500 astronomical units (AU) from the Sun, 500 times the distance between the Earth and the Sun, and closer than the legendary Planet Nine.

According to experts, KBP is up to three times as massive as Earth, but its temperatures are probably too low to support life as we know it.

According to the study authors, such assumptions are independent of the supposed Planet Nine, which some have theorized to be much more massive and farther away than a potential Earth-like planet in the Kuiper Belt.