“Cosmos was only discovered yesterday. For a million years it was clear to everyone that they were no other places than the Earth. Then in the last tenth of a percent of the lifetime of our species ….that we were not the center and purpose of the Universe, but rather lived on a tiny and fragile world lost in immensity and eternity drifting in a great cosmic ocean dotted here and there with hundred billion galaxies and billion and trillions of stars”…. (Carl Sagan)
Jupiter is the largest planet in our Solar System and Europa is one of its several moons.
Europa is one of the most fascinating moons of Jupiter. It is one of the four Galilean moons. The others are Io, Ganymede, and Callisto. They were discovered by Italian Scientist Galileo in the year 1610. Europa is claimed to have been discovered by a German astronomer Simon Marius too.
Europa is named after the Greek beautiful Phoenician princess who was courted by Zeus and became the Queen of Crete.
Europa surface is the brightest in the solar system due to the reflection of the sunlight on its icy crust.
Europa surface is mostly water ice. It may be covering an ocean beneath. If so, it may be the only place in the solar system besides Earth where liquid water exists in abundance. Life forms have been found thriving at the extreme locations of Earth and at the subterranean regions of the volcanoes that may be similar to what may exist on Europa,….it may harbor life there too.
Jupiter's Europa might not only sustain, but foster life, according to the research of University of Arizona's Richard Greenberg, a professor of planetary sciences and member of the Imaging Team for NASA's Galileo Jupiter-orbiter spacecraft.
"The real key to life on Europa," Greenburg adds, "is the permeability of the ice crust. There is strong evidence that the ocean below the ice is connected to the surface through cracks and melting, at various times and places. As a result, then, if there is one, includes not just the liquid water ocean, but it extends through the ice up to the surface where there is access to oxidants, organic compounds, and light for photosynthesis. The physical setting provides a variety of potentially habitable and evolving niches. If there is life there, it would not necessarily be restricted to microorganisms."
Recent data from Galileo Orbiter showed that Europa has an induced magnetic field through interaction with Jupiter which suggests the presence of subsurface conductive layer.
Its surface is very smooth with very few (three) crates larger than five km. in diameter. Most striking aspect of Europa are dark streaks criss crossed, resembles the scribbling of a child. The latest theory about their origin is that they are produced by a series of volcanic eruptions or geysers.
Europa orbits Jupiter in just three and a half days. The orbital radius is about 670,900 km. Europa spins faster than it orbits. This suggests an asymmetry in internal mass distribution and that a layer of subsurface liquid separates the icy crust from the rocky interior.
Europa probably consists of metallic iron core. It is slightly smaller that Earths moon.
Orbit: 670,900 km from Jupiter
Diameter: 3138 km
Mass : 4.80e22 kg
With input from scientists around the world, American and European scientists working on the potential next new mission to the Jupiter system have announced their joint vision for the Europa Jupiter System Mission to explore "the emergence of habitable worlds around gas giants."
from Prajakta Dighe
my above article got published in The Hitavada dt 31/7/2011
No comments:
Post a Comment