Seth Shostak: Extraterrestrial Habitats: Yet More Good News

It really is a comment I get far more typically than a shoe shine: “Couldn’t we be the first intelligent species in the universe? After all, it took eons to cook up the elements of life — so possibly we’re the first ones out of the gate.”

The logic seems believable. After all, we (and our world) are star stuff, as Carl Sagan was fond of saying. But we’re not just any star stuff, most of which is humdrum hydrogen and listless helium. Our bodies consist of fancier ingredients like carbon, oxygen, nitrogen, phosphorous, and a couple of other herbs and spices. And Earth-like planets are built of this stuff and far more (feel silicon and iron).

These heavier elements (and they’re only “heavy” compared to hydrogen and helium) weren’t created in the hellish fireball of the Large Bang. Rather, they’ve been slowly roasted into existence deep inside the cores of big stars. They became offered for fashioning planets and people only when these stars died and belched their chemical-saturated innards into space.

Clearly, enriching the cosmos with heavy elements takes a although. So there’s inevitably an interval between the sterile aftermath of the Big Bang and a time when the cosmic, chemistry set had adequate ingredients to make rocky planets (and squishy biology). It is that interval that motivates comments about Earthlings possibly getting the first out of the gate.

Well, it appears you can quit preening. Regardless of any inclination to believe yourself among the brightest bulbs about, new research indicates that even when the universe was significantly younger, there had been heavy components enough to spawn planets that could … spawn life.

A team of astronomers led by Lars Buchhave at the University of Copenhagen has combined data from NASA’s Kepler space telescope and instruments on the ground to analyze the prevalence of terrestrial-size worlds. And to everyone’s surprise, they find that even so-named “metal-poor” stars are encircled by rocky planets. Metal-poor is just astronomer lingo for “not several heavy components.”

In other words, just as almost any earthly environment can develop moss, so too can just about any star system develop tiny, tough planets like Mercury, Mars, Venus and Earth. And these are precisely the variety of worlds we really feel are best for biology. They’ve got solid surfaces, and the correct chemical ingredients.


Sources and more information:

• A Game-Changer for the Search for Alien Life: “All stars have planets”

Astronomers working with the Kepler spacecraft have announced new evidence suggesting that there are far more potentially habitable planets in our galaxy than we had believed. And just as surprisingly, these planets emerged much longer ago than expected – a revelation that could have profound implications in the search for extraterrestrial..

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