Know why Earth became habitable and not Venus
London, July 22: Information about the improbable evolutionary path that enabled Earth and not Venus to sustain life has been found, shows research.
Venus is the most similar planet to Earth in terms of size, mass, density, gravity and composition in our solar system.
According to researchers, Earth's first crust, which was rich in radioactive heat-producing elements such as uranium and potassium, was torn from the planet and lost to space when asteroids bombarded the planet early in its history.
It's
official:
2014
was
Earth's
hottest
year
on
record
"The early loss of these two elements ultimately determined the evolution of Earth's plate tectonics, magnetic field and climate," said the team from University of British Columbia (UBC) and University of California-Santa Barbara.
"The events that define the early formation and bulk composition of Earth govern, in part, the subsequent tectonic, magnetic and climatic histories of our planet, all of which have to work together to create the Earth in which we live," said Mark Jellinek, professor at UBC.
It is these events that potentially differentiate Earth from other planets.
On Earth, shifting tectonic plates cause regular overturning of Earth's surface, which steadily cools the underlying mantle, maintains the planet's strong magnetic field and stimulates volcanic activity.
Pluto
plain
resembles
frozen
mud
cracks
on
Earth
"Earth could have easily ended up like present day Venus. A key difference that can tip the balance, however, may be differing extents of impact erosion," added Matt Jackson, associate professor at University of California.
With less impact erosion, Venus would cool episodically with catastrophic swings in the intensity of volcanic activity driving dramatic and billion-year-long swings in climate, said the study that appeared in the journal Nature Geoscience.
"There are some very special set of circumstances that make Earth," the authors said.
IANS