A group of astronomers, including Avi Loeb at Harvard University, suggested Planet Nine may be a tiny black hole somewhere out in the Oort Cloud. If Planet Nine turns out to be Black Hole Nine instead, it's probably about the size of a grapefruit but about 5 to 10 times the mass of Earth.
Those anomalies would come and go as objects move in front of a distant star and continue in their orbit. But if the object is a planet-mass black hole, the physicists say, it would likely be surrounded by a halo of dark matter that could stretch up to 1 billion kilometers on every side.
A blanet is a member of a hypothetical class of exoplanets that orbit black holes. Blanets are fundamentally similar to planets; they have enough mass to be rounded by their own gravity, but are not massive enough to start thermonuclear fusion, just like planets that orbit stars.
In 1930, Pluto was discovered and officially named the ninth planet.
Its elusive nature suggests that it's at the far edge of its enormous orbit, meaning it's unlikely to be reflecting much light from the Sun. As such, it will remain in shadow, hidden within the sparkling starfield of the Milky Way.
Another planet or Another Dimension that, by the time we get to see it, has been left in ruins for a long, long time. There are signs here and there that this world once boasted a civilization, maybe even a great civilization, but all that's left now are a few decaying remnants.
This hypothetical Neptune-sized planet orbits our Sun in a highly elongated orbit far beyond Pluto. The object, which the researchers have nicknamed "Planet Nine," could have a mass about 10 times that of Earth and orbit about 20 times farther from the Sun on average than Neptune.
The odds of this occurring has been estimated at a few percent. Had it not been flung into the Solar System's farthest reaches, Planet Nine could have accreted more mass from the proto-planetary disk and developed into the core of a gas giant.
The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. Essentially Pluto meets all the criteria except one—it “has not cleared its neighboring region of other objects.”
The inequality suggests that to destroy a black hole, all you need to do is to feed it angular momentum and charge. But that hides a multitude of problems. For a start, things with angular momentum and charge also tend to have mass. And in any case, the equation above describes a steady state.
Our Universe appears to be expanding and cooling, having originated some 13.8 billion years ago in a hot Big Bang. However, it's plausible that what we see from inside our Universe is simply the result of being inside a black hole that formed from some parent Universe.
Despite their abundance, there is no reason to panic: black holes will not devour Earth nor the Universe. It is incredibly unlikely that Earth would ever fall into a black hole. This is because, at a distance, their gravitational pull is no more compelling than a star of the same mass.
The possibility that a black hole could actually impact Earth may seem straight out of science fiction, but the reality is that microscopic primordial black holes could actually hit Earth. If one did, it wouldn't just impact like an asteroid, it'd pass straight through the entire Earth and exit the other side.
Researchers from Harvard University have published a paper that explores the possibility that our solar system is home to a tiny, ancient black hole. For decades, the solar system had nine official planets, but Pluto was kicked out of the planet club and demoted to dwarf planet status.
Located just under 1,600 light-years away, the discovery suggests there might be a sizable population of dormant black holes in binary systems. The black hole Gaia BH1, seen in this artist's concept near its Sun-like companion star, is the closest black hole to Earth discovered so far.
Scientists hunted for 6 years and found nothing significant. Astronomers searching for our solar system's elusive Planet Nine — a theoretical world that may lurk deep in a cloud of icy rocks far beyond the orbit of Neptune — have come up short once again.
In 2006 the International Astronomical Union (IAU) demoted the much-loved Pluto from its position as the ninth planet from the Sun to one of five “dwarf planets.” The IAU had likely not anticipated the widespread outrage that followed the change in the solar system's lineup.
The team discovered that using current, unmanned transportation methods, it would take 45 to 75 years to get to Planet 9, which is about 42 billion miles away from Earth. By comparison, Pluto, which is the ninth object from the Sun, is roughly three billion miles from Earth.
In the outer Solar System, well beyond the orbit of Neptune and Pluto, a ninth planet may be waiting to be discovered. This 'ghost planet', nicknamed Planet 9 or Planet X, has never been observed directly, but peculiar goings-on in the space beyond Neptune hint tantalisingly at its existence.
Eris (dwarf planet)
This speculative "Planet 9," according to estimates, would be about 5-10 Earth-masses in size and orbit about 400-800 au from the Sun. A planet at this distance would be extremely difficult to spot in normal optical sky searches because of its faintness, even to telescopes like PanSTARRS and LSST.
There have been journeys to the inner planets: the Messenger, Magellan and Mariner spacecraft to Mercury and Venus. There have, too, been expeditions to Jupiter and Saturn and their colorful flocks of moons. Asteroids and comets and the sun itself have also been studied up close. Many of the missions are ongoing.