Orbital chaos may cause planetary smash-up within solar system

BEIJING, June 11 (Xinhuanet) -- A new study in
the Thursday's issue of Nature predicts there's a real, albeit slim, possibility of a
planetary smash-up inside the inner solar system due to the Mercury's distinctly
lopsided orbit.

Forget sendingprobe to Mars, the planet may
come crashing right here to Earth if gravitational interactions substantially
agitate its now-stable orbit.

Boffins Jacques Laskar and Mickael Gastineau of the
Paris Observatory say results of a new computer model show a roughly one percent
chance within the next five billion years that such a planetary apocalypse will
happen.

The researchers simulated the most current data
available on the interactions of solar system's eight planets (with the edition
of Pluto and Earth's moon) over the course of five billion years -- a point in
which the sun is expected to swell into a red giant andswallow the inner
planets.

Mercury is a particular nuisance to the stability of
the solar system because its orbit is a slightly elongated ellipse, leaving it
more vulnerable to being swayed by gravity of the large outer planets like
Jupiter.

Out of 2,501 scenarios sequentially nudging Mercury's
orbit by only 0.38 millimeters, 25 lead to a large enough increase in the
planet's orbital eccentricity to allow collisions with Venus or the sun.

In one simulation, Mercury smashes into Venus about
1.76 billion years from now. In three others, Mercury falls into the sun.

In yet another, Mercury's gravitational tug yanks
Mars within 800 kilometers of Earth 3.34 billion years from now, causing the red
planet to rip apart and shower Earth with debris.

Astronomers believe the solar system is about 4.6
billion years old.

(Agencies)