Space Trekkers Live in Binary Planetary Systems

July 05, 2009

For years I’ve hypothesized that binary planetary systems exist, and that these are the places to go looking for space-faring civilizations.  By binary planetary system I mean a pair of gravitationally bound stars, each with its own independent family of worlds.

There could be habitable planets around each star in the binary system, if the stars are far enough apart. If technological civilizations independently evolve around both stars, they could actually travel across space and visit each other. This would be a powerful motivation to build the fusion-powered rockets needed to travel back and forth within a reasonable amount of time.

Astronomers have now found such as system, but we’ll have to wait another 4 billion years before an alien civilization manifests itself. Why? Because the double star is just a few millions of years old, and if Earth is any example, it takes a long time to evolve intelligent beings.

The systems was discovered in a nearby star-factory, the magnificent Orion nebula, located 1,300 light-years away.  In 1995 the Hubble Space Telescope found embryonic planetary systems in Orion, and lots of them. By embryonic I mean pancake disks of dust and gas swirling around a star in the middle of each disk. Planets should quickly agglomerate in these disks over millions of years.

Rita Mann and Jonathan Williams of the Institute for Astronomy in Hawaii used the Submillimeter Array on Mauna Kea to make the observations. Hubble Space Telescope photos also reveal the binary duo, called 253-1536, with a pair of accompanying disks containing enough material to build planets.

The two stars are roughly 50 billion miles apart, or about four solar system diameters (out to the edge of the “outer rim” of the Kupier belt). The stars take 4,500 years to complete one orbit around their common center of gravity.  That’s about the length of recorded human history!

Both stars are red dwarfs that are only about a third the mass of our sun and therefore cooler. Each could gravitationally hold onto a family of planets. There is a reasonable chance a planet could form in each star’s habitable zone, where temperatures allow liquid water to remain on the surface. It’s entirely possible that life could originate on planets in one or both systems.

Let me be wildly optimistic for a moment and jump aboard a time machine to imagine life evolving in parallel if Earthlike planets eventually form in both systems.

If intelligent life is an inevitable milepost in biological evolution, each planet should eventually reach that watershed. But the vagaries of planetary evolution and cosmic catastrophes would likely put biological evolution out of sync between the planets.

To make this even more complex, cultural evolution would progress at a different rate for emerging civilizations on each planet. Carl Sagan lamented that without the heavy hand of the Church, and the mysticism and superstition of the dark ages, (kind of like some of the Internet sites today) we could have been far more technologically advanced today, living in a Jetsons-world of flying cars, and colonizing other planets.

Primitive cultures on both worlds would develop naked-eye astronomy and note the binary stellar companion as a brilliant star in the night sky. It would be about one thousand times brighter than the brightest star in our night sky, Sirius.

When the aliens finally had their incarnation of Galileo Galilei appear, the entity would use a telescope to discover planets around the other star – and maybe then be burned at the stake for heresy.  

The civilization that didn’t execute their Galileo -- and hence was unencumbered by religious political control and dogma -- would have the horse race lead. It would be the first to develop radio communications to eavesdrop on the neighboring system.

They would then send a flyby probe to reconnoiter the other planet. But before this could be accomplished, advanced rocket propulsion would need to be developed to span the 50 billion mile separation within the lifetime of its builders.

The discovery of an inhabited planet in the neighboring system would galvanize the exploring civilization. There might be an Apollo-style crash program between the advanced planet’s nations to be the first to send a crew to visit. This effort could be a huge distraction from those types of activities that dominated Earth’s 20^th century – wars of conquest.

The space vehicle truly would need to be a self-contained “space-city” like Star Trek’s Enterprise.  For a 5-years voyage, a speed of over 100,000 miles per hour would need to be achieved – and that’s not counting time for accelerating and decelerating.

If the neighboring planet hosted a less advanced civilization, there could be a spirited ethics debate over whether to make direct physical contact. But I believe it would inevitably happen if the other planet’s surface environment and life forms were similar in their biochemistry to that of the visiting species.

Or, the advanced civilization may elect to be stealthy and instead monitor the planet from space probes. I guarantee they would not be idiotic enough to buzz farmhouses and carve out crop circles, as the UFO fanatics believe happens here on Earth.

If direct contact were made, the less advance civilization could either benefit or suffer. But it truly would be “The Day The Earth Stood Still” for them. It might even dominate their news cycle for more days than Michael Jackson’s recent death did.

In the most cynical scenario, the advanced civilization invades the other planet and seeks to colonize it in an H.G. Wells’ War of the Worlds replay. Given the great separation between the planets, such an invasion would be extremely difficult to pull off from a logistics point of view.

On a much more optimistic note, the two cultures might simply evolve to exchange trade, though the cost of imported goods would, literally, be astronomical. And, don’t expect any of Star Trek’s green-skinned Orion slave girls – the alien biologies would never be that parallel!

But we’ll have to wait several billion years for this system to evolve to see any action. If we get really lucky, we might someday find a mature clone of this system. And if we’re very lucky, we’d be on the same orbital plane as the communication line-of-sight between the two inhabited planets. Then we might eavesdrop on a flurry of radio telecommunications that might be ongoing between the two worlds.

Ironically, a one-way radio message between binary system planets in Orion would take under three days to get to the receiver, about the same amount of time for a postcard to arrive in the mail.

Comments

[Michael L]

I thought binary systems were fairly common?

[Ray]

Approximately half of the stars in the Milky Way are in multiple star systems.

Widely separated systems with independent planets should be common too, I imagine.

But this is the first system that we have good observational evidence for a robust protoplanetary disk around each star.