It's a common pet peeve among sci-fi fans: why do aliens always seem so undeniably human? Shouldn't a strange new consciousness from a far-away world seem more alien? And not just in looks - we've written about human-looking aliens before - but in motivations and behavior as well.

For instance, there's no reason to assume that an alien species would look like a human with a weird forehead. But there's also no reason to assume that aliens would have a human-like conception of property or of societal connection or even of self.

While what seems to be a majority of science fiction relies very heavily on making their aliens as behaviorally human as possible, there are a few aliens in the cannon that challenge our perceptions of aliens and what a true other might actually be like. Here are some examples of truly alien aliens (each include some spoilers).

Solaris

In one of the only common features between both film versions of Solaris and the original novel, one of the main objects of the story is to present a truly "other" alien. In Solaris, human scientists have stumbled upon a planet that seems to be covered in a living ocean. So, they attempt to communicate with it.

And the "ocean" communicates back in the only way it knows how: by conjuring up living manifestations of the deeply hidden tragedies and shames of the scientific crew. The films hint at what is the novel's focus: the sentient oceans are so alien from humanity that its attempts to communicate look more like torture. All three versions leave the audience with no clue as to what the sentient oceans actually want. And that's a lot more realistic than clear communication between two wildly different species.

The 456

The motivations of the 456 in Torchwood's Children of Earth miniseries are a lot clearer: they just want Earth's children for what appears to be a very gruesome narcotic-like use. But what makes the 456 so great an example of an alien species is that this use is never clear, and humanity is in no position to investigate the aliens.

It's another common misstep in alien stories: unlocking the biological or scientific secrets of the alien proves the necessary step to defeating them. In this story, the alien remains callously and disturbingly other throughout. It's like "To Serve Man" with a decidedly Lovecraftian twist.

The creature from Midnight

In the Dr. Who episode "Midnight," we see that in science fiction stories, you don't always need a malicious alien to find a villain. The alien in this case is certainly creepy, and its "voice stealing" method of communicating makes the viewer squirm, but in the end, the ones that we fear the most are not aliens, but other humans.

And that is what makes this, along with Children of Earth, such a great alien story: no matter what the extra-planetary life is, the much more frightening thing is the paranoia and fear-induced violence that this alien consciousness causes.

Rama

While Rama in Arthur C. Clarke's Rama series is actually a place, it reveals another misstep in most alien portrayals. When humans land on Rama and begin exploring, they are struck by how strange the place is. The "buildings" don't appear to actually be buildings, the "cities" are apparently uninhabited, and the sheer scope and engineering of the place betray a fundamental flaw in any human-assumption-based analysis of the place.

While this unknowable other concept gets shelved a bit in the sequels to Rendezvous with Rama, the first book ends as it might in reality: the craft moves on, and humanity is no wiser than before. Rama remains a foreign thing, even after all is supposedly "revealed."

(From this short film based on the book Rendezvous with Rama)

The Buggers and the Piggies

Finally, in Orson Scott Card's Ender's Game, and maybe more so in its sequel, Speaker for the Dead, we see two new alien races that eventually challenge humanity to tolerate and maybe even love something truly other. The buggers start the story as the frightening antagonist, but it's revealed that their acts of aggression were really attempts at communication. The piggies, on the other hand, seem wild and unpredictable at first, but their horrific acts were really ceremonies of great honor.

The reality of these books, though, is that, when all is said and done, the humans in these stories find the humanity in an inscrutable other. They prove to us that something menacing and indifferent and entirely alien can sometimes become almost human. And even if that means humanizing the aliens slightly, it's a feat that's far more impressive than getting us to sympathize with blue versions of ourselves.

5.94 million people tuned in for the first episode of the show's third season, it's first on BBC One. If that doesn't sound like a lot, previous season premieres have pulled in 2.4m (Season One on BBC Three) and 3.72m (Season Two on BBC Two), making 5.94 million an impressive leap (more than double than that of its lead-in, an episode of current affairs show Panorama) - and also enough people to win the timeslot for the night.

The season continues this evening and for the rest of the week on BBC One, before premiering in America on BBC America July 20th.

5.9m tune in for new 'Torchwood' [Digital Spy]

SFX Magazine talked to producer Peter Bennett about what's different - and what's the same - about the third season of the British sex-and-aliens drama:

We actually take this series on a darker journey, if anything. But Children Of Earth is still the same show. Jack is still as cheeky and irreverent and sexy. Telling one big story meant that the story had more scale and reach than we ever had in series two, but no, nothing's changed... When we set out we did initially think it would be nice to go down the kind of Bourne Identity route, make it very thriller-like. But after our first couple of tone meetings it was evident that actually that wasn't the way that Russell saw it. Although between Euros [Lyn, the director] and I we did try and put a certain amount of our stamp on it, at the end of the day, as Russell said, it's still gotta be Torchwood. It's still got to be fun-packed; yes, it can be thrilling, but it's still got to have the real Torchwood feel.

Does that mean that at least one of the episodes will be a distinct let-down and kind of embarrassing to watch for everyone involved? It wouldn't be Torchwood without that happening.

Children of Earth launches tonight in the UK on BBC One, and July 20th in the US on BBC America.

Torchwood producer talks Children Of Earth [SFX Magazine]

The packet includes a much more detailed plot summary for "Children Of Earth" than we've seen before.

An ordinary day becomes a world of terror, as every single child in the world stops. A message is sent to all the governments of Earth: "We are coming".

But as a trap closes around Captain Jack, sins of the past are returning, as long-forgotten events from 1965 threaten to reveal an awful truth.

Torchwood are forced underground, as the government takes swift and brutal action. With members of the team being hunted down, Britain risks becoming a rogue state, with the mysterious and powerful 456 drawing ever closer.

Captain Jack (John Barrowman), Gwen (Eve Myles) and Ianto (Gareth David-Lloyd) are helpless, as events escalate until humankind faces the end of civilisation itself.

Apart from the part about creepy children, it all sounds fantastic. And I think raising the stakes dramatically for Captain Jack and the crew would be a huge plus. As long as Torchwood was just a show about the team capturing escaped monsters, or dealing with Captain Jack's brother and Captain Jack's ex-boyfriend, it always felt a bit trivial — like if Captain Jack just up and left, most of the problems he was fighting against would disappear as well. But now, at last, there's a real threat to the Earth. Contrast that with Davies' Doctor Who, which hasn't really got anyplace else to go after his constant upping of the ante.

Oh, and the political part? Well, there's the idea of Britain becoming a "rogue state" as it crumbles under the weight of whatever those secrets from 1965 are. But there's also this, from Davies:

But underneath the sci-fi and the aliens there's something very relevant to the world, I hope, the way we sit in the West and watch footage of atrocities in different countries and imagine it's all so far away, and so impossible here – which is a nice, comfy lie we tell ourselves. That was the heart of it.

I wanted to tell a story in which civilisation snaps, in which we turn on ourselves, in which nothing is safe. Plenty of people live like that on this planet. In this story, it's Britain's turn!

Davies also talks up the episode's guest stars, including Cush Jumbo as Lois, the innocent secretary who discovers government secrets on her computer, and Peter Capaldi as Frobisher, who's "heartbreaking" at the end. And Susan Brown is a "slow burner" as Bridget Spears. Nicholas Farrell is the most clever and manipulative British prime minister you could imagine. (And I wonder if they'll refer to what happened to the last PM, and the fact that Jack was there.) And then Lucy Cohu plays Alice... Captain Jack's daughter.

Davies also promises that the huge threat of the aliens, the 456, breaks down Torchwood and forces them to rebuild, so we see a new side of them and witness their humanity. And in episode three, we actually get to watch the British government engaging in diplomatic relations with an alien race, and it's just the way you'd imagine.

Most importantly, though, Davies hints that the relationship between Captain Jack and his very private secretary, Ianto, has "developed."

Torchwood's "Children Of Earth" airs July 20 through July 24 on both BBC One in the U.K. and BBC America in the U.S.

Torchwood: Children of Earth premieres this July.

We've known for awhile that Torchwood's experimental third season - five episodes to be shown nightly over the course of a week - was going to be previewed on June 12th at the British National Film Theater, as well as that BBC America planned to show the episodes simultaneously with their British broadcast, but BBCA confirmed yesterday that the episodes would be shown at some point in July, and presumably before this year's San Diego Comic-Con (unless they want to lose some of their potential audience).

'Torchwood' to return in July with 'Children of Earth' [Chicago Tribune]