TITLE: Could Uranus be an alien planet? Writer claims its possible


Uranus might be an alien planet, according to writer Brian G Turner, who was born and raised in Hull, but later moved to Scotland. Although it might sound far-fetched, Turner says there's enough circumstantial evidence to consider the possibility. 

That's just one of his claims in his latest book, "The Living Universe", which sets out to show how the latest scientific discoveries are rewriting what we know about space, planets, and the origins of life.


SUBTITLE: An odd planet

Uranus is unique among the planets because it spins on its side as it orbits the Sun. The moons of Uranus orbit its equator, so they also look like they're orbiting sideways compared to the rest of the planets.

According to current theory, Uranus spins on its side because of a giant collision sometime in the past. This is where Turner says things start to fall apart, because there's no actual evidence for such a collision. 

Turner says, "There are a number of models suggesting that Uranus was struck by a giant planet, perhaps as much as four times bigger than our Earth, and this collision knocked Uranus over. The problem is, we have no idea what the interior of Uranus is like, let alone that of any giant planet crashing into it. So the collision models have no accurate data to work with, which means they're all based on guesswork. That's not a basis for serious science.

"Additionally," Turner says, "we've sent space probes to look at the moons around gas giants planets, and all of those show massive impact craters, yet none of them have been flipped sideways by such collisions.

"On top of that, if Uranus was struck by a planet four-times bigger than our Earth, the inevitable questions is where did it came from? The impact models demand that our Solar System used to have a massive unknown planet. That means rewriting the history of the Solar System, but the people arguing for the collision models never get around to that." 


SUBTITLE: Wandering planets

So, what does Turner think might have happened instead? 

"Over the past few decades we've discovered that most stars have planets - exoplanets, as we call them. One of the most common form is known as a Hot Jupiter, which is a gas giant planet orbiting very close to its star. It's believed these spiralled into this position, and in doing so would have hurled any other planets in its way out of that star system and into interstellar space.

"That means we space must contain a significant number of these ejected exoplanets, which can be captured in turn by any other star they pass too close to. We've discovered more than 6,000 exoplanets, and many of these exist in orbits that make no sense unless the planet was captured. Examples include planets orbiting backwards, or sideways."

How does all this apply to Uranus? Turner says, "It's not impossible that Uranus was ejected from another star system, and left to wander through space until it was captured by the gravity of the Solar System. 


SUBTITLE: Tilting stars

That still doesn't explain why Uranus orbits the Sun on its side. Or does it?

"Stars commonly have a tilt," continues Turner. "Our Sun is tilted 60 degree to the disk of the Milky Way, our home galaxy. We know other stars have different tilts. Therefore the seeming odd tilt of Uranus could simply be the tilt of its original star."

It's one thing to suggest the possibility, but is there any actual evidence for this alternative explanation? Turner thinks so. "Another odd thing about Uranus is that it's much colder than the other planets, even colder than Neptune, which is a billion miles farther away from the Sun. That could be the result of it having wandered for a long time through cold interstellar space. However, because we didn't see such an event happen, we're left looking at clues in the Solar System and speculating on possibilities."

Does this mean Uranus might not actually have been captured? 

"It's more that we'd need evidence to support the idea, but for the time being I would argue it's a possibility that needs to be taken more seriously. For too long we've imagined the Solar System is somehow cut off from outside influences from the rest of our galaxy. However, with potentially trillions of wandering planets in a galaxy of hundreds of billions of stars, over billions of years even seemingly unlikely events are more likely to happen. That's something my book explores further."

"The Living Universe" by Brian G Turner is dedicated to his school physics teacher, Mr Mesens, who taught at Wolfreton School before moving on to become Head of Science at Trinity College.

The book is available exclusively at Amazon.