NASA has got some very high
quality photos of the fifth planet from sun, Jupiter. As NASA's Juno probe just passed closer to Jupiter than any human-made craft ever. It looks pretty huge
in the photos. It’s 2.5 times the mass of all other planets in the solar system
combined and it's so huge, in fact, that it doesn't actually orbit the sun. Actually,
it's big enough that the center of gravity between Jupiter and the sun doesn't actually
reside inside the sun rather, at a point in space just above the sun's surface.
As Earth orbiting the
much-larger sun and we are very much familiar with this situation. The center
of gravity resides so close to the center of the larger object that the impact
of this phenomenon is negligible. The bigger object doesn't really move and the
smaller one starts orbiting around it.
But when a small object
orbits a big object in space, the less massive one doesn't really travel in a
perfect circle around the larger one. In fact, both objects orbit a combined
center of gravity.
To elaborate this situation
more clearly we’ll take the example of ISS. When the International Space
Station (ISS) orbits the Earth, both the Earth and the space station orbit around
their combined center of gravity.
But that center of gravity
is so ridiculously close to the center of the Earth that the planet's motion
around the point is impossible to spot, and the ISS made a near-perfect circle
around the whole planet. Same thing happens when most of the planets orbit the
sun.
Both the sun and the Jupiter
orbit around a specific point. The gas giant is so big that its center of mass
with the sun, actually lies 7% of a sun-radius above the sun's surface.
If we just see the sizes of
both, Jupiter is still only a fraction of the sun's size. That is, in essence,
how Jupiter and the sun move through space together.
But this is an interesting
thing to say that Jupiter is so massive, it doesn't orbit the sun.
