London: If an electrical engineer from the US is to be believed, life on planets like Earth, or hypothetically, even Mars, could have been seeded by electrically charged microbes from space.
The discovery of meteorites from Mars on Earth in the 1990s had earlier given rise to speculation that living microbes could have travelled back and forth between the two planets, perhaps even allowing one planet to seed life on the other.
But such a thing could only happen after a huge asteroid collided with one of the planets, and the impact was large enough to blast rocks off the planet's surface. Such strikes are extremely rare and only a handful are thought to have occurred since the solar system came into existence.
Tom Dehel, an electrical engineer at the US Federal Aviation Administration, investigated how electromagnetic fields in the Earth's atmosphere affected GPS satellites and disrupted their use for aircraft navigation. He calculated the effect of electric fields at various levels in the atmosphere on a bacterium that was carrying an electric charge and found that such bacteria could easily be ejected from the Earth's gravitational field by the same kind of electromagnetic fields that caused auroras.
More surprisingly, these fields occurred every day, unlike the extraordinarily large surface impacts needed to eject interplanetary meteorites. He said this was a much gentler and steadier way for microbial life to leave a planet and travel to other worlds - and even from one solar system to another, something even the biggest impacts could not do.
Findings revealed that field strength varied greatly at different levels of the atmosphere and the strongest ones were near the surface, generated by thunderstorms. Also there was the possibility of large gaps in the field strength where the fields had not been measured directly.
Assuming that the fields extended through the whole air column, there could be an ongoing, sustained process of lofting bacteria high into the atmosphere, he said.
?Since the upward forces of the magnetic field would balance the force of gravity for tiny organisms, they could float in the upper atmosphere for years and reproduce there, giving them a chance to evolve capabilities to endure the hardships of that environment, including coping with strong UV and a near-vacuum. Such organisms would thus be well equipped to endure the rigours of a journey through space,? New Scientist quoted Denel as saying.
Charged microbes could also be propelled outwards from a planet at high speed by ?magnetospheric plasmoids? - independent structures of plasma and magnetic fields that can be swept away from the Earth?s magnetosphere, he said.
?Hitching rides on these structures could accelerate microbes to speeds capable of taking them out of the solar system and on to the planets of other stars. And because of the potential for a steady outflow of the particles pushed by the electric fields, a single life-bearing world might seed an entire galaxy with life,? he added.
The findings were presented at the biennial meeting of the international Committee on Space Research (COSPAR), in Beijing, China, this week.
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