A MULTIPLE PLANET SOLAR SYSTEM    DISCOVERED

Planetary scientists have discovered what they claim is an unusual multiple-planet solar system containing a super-earth and two Neptune size planets orbiting in resonance with each other.

The planets have been designated b, c, and d. all three planets orbit much closer to kepler-18, a star similar to the sun.

Planets weighs in at about 6.9 times the mass of earth, and is twice earth’s size and considered as super earth with a 3.5 –day period ; planet c has a mass about 17 earths, is about 5.5 times earth’s size and orbit s kepler-18 in 7.6 days. Planet d weighs in at 16 earths at 7 times earth’s size, and has a 14.9 day orbit.

But the times that  c and d transit the face of kepler-18 “are not staying exactly on that orbital period”, one is slightly early when the other one is slightly late, then both are on time at the same time, and then vice-versa.

Scientifically speaking, c and d are orbiting in a 2:1 resonance “it means they’re interacting with each other. When they are close to each other, they exchange energy pull and tug on each other.

Kepler uses the transit method to look for planets. It monitors a star’s brightness over time, looking for periodic dips that may indicate a planet passing in front of the star.