Fluctuating Tilt In Planet's Orbit Could Harbor Life: Astronomers
A fluctuating tilt in a planet's orbit doest not make life impossible, according to a new research. In fact, it might be helpful sometimes.
Researchers explained that such 'tilt-a-worlds' - as astronomers call them - turned from their orbital plane by the influence of nearby planets - are less likely than fixed-spin planets to freeze over because of the even distribution of heat from their host star.
They added that this happened only at the outer edge of a star's habitable zone. The habitable zone is the swath of space around it where rocky worlds could maintain liquid water at their surface which is ultimately the necessary condition for life.
"Without this sort of 'home base' for ice, global glaciation is more difficult," said UW astronomer Rory Barnes in the press release who is the second author on the paper. "So the rapid tilting of an exoplanet actually increases the likelihood that there might be liquid water on a planet's surface."
Barnes said Earth and its neighbor planets occupied roughly same plane in space but evidences exist of systems whose planets ride along at angles to each other. In a way that "they can tug on each other from above or below, changing their poles' direction compared to the host star."
The findings of the study argue against the long-held view among astronomers that a planet needs the stabilizing influence of a large moon to have a chance at hosting life.
"We're finding that planets don't have to have a stable tilt to be habitable," Barnes added in the press release. "Minus the moon, Earth's tilt, now at a fairly stable 23.5 degrees, might increase by 10 degrees or so. Climates might fluctuate, but life would still be possible.
This study suggests the presence of a large moon might inhibit life, at least at the edge of the habitable zone."
The findings of the study have been published in the journal Astrobiology.