Steven Hawking, the eminent astrophysicist, declares in a new Discovery Channel series that aliens coming to Earth are not likely to be friendly.

“We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet. I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach.”

It does sound like the discussion about BEMs, circa 1955. During the early years of the post World War II, Cold War, Atomic Bomb era, it was fashionable for popular entertainment to highlight the danger of Earth being attacked by aliens – a.k.a. Bug Eyed Monsters (BEM). It was part of a long tradition in science fiction to view the arrival of visitors from outer space as hostile. More recent vintage Hollywood efforts along the line Hawking suggests include the two V series, Independence Day, and War of the Worlds. In short, the ticket has been punched more than a few times on that train of thought.

Since Hawking is neither stupid nor unacquainted with science fiction, there is more than a little suspicion he may be putting his spin on stirring the pot. You know, get the folks thinking again.

However, he said something else that will probably be overlooked: “Most life elsewhere in the universe is likely to consist of microbes.”

It consists mostly of microbes here too. From what we’re learning about life in extreme conditions, and from the number of worlds out there that have nothing but extreme conditions (including several in our own solar system), it seems like a fairly safe statement to say we’re most likely to encounter microbes rather than advanced space-faring civilizations.

As Hawking emphasizes, the probability of finding life elsewhere in the universe is – well, astronomically high. I won’t repeat the mathematical logic; it involves billions of worlds capable of sustaining some kind of life. The odds for life in our own solar system climb almost every year. Mars, in particular, seems most likely, and yes, Martians will almost certainly be microbes. (Microbes = bacteria, archaea, viruses – or something like them.)

I’m guessing, but reading between the lines of what Hawking has said before and is reputed to say in the new series, his concern isn’t really about finding BEMs or any other (hostile or not) advanced form of life. It’s about getting us to think about the life around us, from the smallest to the largest. He wants us to think about what it will take to sustain life – especially ours – both here on Earth, if possible; elsewhere, as necessary.

For Hawking, the spread of humanity, at least through the solar system is a requirement for our future. It’s our insurance against species destruction if a large asteroid hits Earth, or we exercise our ability to self destruct.

Like he said: “We have only to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet.”

Look at ourselves, he said.