Cosmic Dust Could Form Inorganic Life, Study Suggests
for National Geographic News
|September 17, 2007|
A recent study suggests that dust in interstellar space can arrange itself into structures that resemble inorganic life-forms.
According to a team of Russian scientists, lifelike behavior could occur in certain configurations of plasma—a state of matter composed of electrically charged atoms.
The claim has drawn mostly baffled, and skeptical, responses from physicists and alien-life experts.
Vast, diffuse clouds of dust and plasma are prevalent throughout the universe. (See a National Geographic magazine feature on "Dust in Space".)
Using computer simulations, a team led by Vadim Tsytovich, of Russia's General Physics Institute in Moscow, found that under certain conditions dust and plasma can organize into stable, helix-shaped structures resembling DNA.
While the structures exhibit none of the complex chemistry associated with even the simplest forms of life on Earth, they appear to at least mimic some the basic processes associated with living systems, the team said.
For example, the helical strands were sometimes capable of reproducing by splitting and reassembling into two identical copies.
The structures also exhibited a kind of evolution, according to the researchers.
Structural changes that took place in the strands were passed from one "generation" to the next, the researchers said. As conditions changed, only the most stable configurations were able to persist.
Because of these and other characteristics, Tsytovich's team argued that the dusty plasma structures should be considered a form of inorganic life.
"It appears from our numerical simulations that large assemblies of dusty plasmas may satisfy the commonly accepted minimum conditions used to define life," said co-author Gregor Morfill of the Max Planck Institute for Extraterrestrial Physics in Germany.
Morfill said that while the results were based on computer models, lifelike plasmas may one day be discovered in space.
"[Given] a sufficient concentration of charged dust, the process of self-organization and growth can be triggered," Morfill said.
"My best guess as to where such systems could develop would be the quiet and benign environment inside interstellar dust clouds," he added.
The study appeared in the August issue of the New Journal of Physics.
Dust to Life?
Other scientists are skeptical that space dust may form a kind of inorganic life. All life on Earth is considered organic, or carbon-based.
Several researchers declined to comment on the record but suggested the claim of lifelike behavior exhibited by the material was highly speculative.
(Read related story: "Alien Life May Be 'Weirder' Than Scientists Think, Report Says" [July 6, 2007].)
But Mihaly Horanyi, a plasma physicist at the University of Colorado, said the behavior of the structures is "amazing," regardless of whether they are classified as truly living.
"I trust that the physics is sound," Horanyi said. "You could reproduce these results experimentally.
"At some level the statement [that the structures may be forms of life] is almost tongue in cheek," Horanyi said.
"It's more a philosophical question—how do you define life?
"This is a very original, very intelligent paper that will trigger a lot of debate," Horanyi added.
Co-author Morfill said that such a debate was exactly the researchers' goal.
"It all comes down to a definition of life, and there the experts will need to come to terms with other issues as well," Morfill said.
"Since these are only definitions, which can be changed, I hesitate to call these systems life myself. I prefer to view our results as an interdisciplinary, thought-provoking trigger for further research."
Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
|© 1996-2008 National Geographic Society. All rights reserved.|