When it comes to planets, our Solar System is rather unique in that it possesses a broad mixture of specimens. We have the smaller, rocky planets in close to the sun; an extensive asteroid field followed by gas giants; ice giants even further out than that; and one or two examples right at the very edge of the system that continue to surprise us, even now.
But when it comes to the granddaddy of planets, Jupiter is king.
With a mean radius of just under 70,000 kilometers (That’s 11 X that of the Earth), Jupiter has a mass one-thousandth that of the Sun, but two-and-a-half that of all the other planets combined. And even though its hundreds of millions of kilometers away, its still one of the brightest objects in the night sky. Do you know, there are even dwarf suns that are smaller than Jupiter!
Sounds impressive, doesn’t it?
However, in the grand scheme of things, Jupiter isn’t really all that imposing, even in our neck of the galactic woods. What do I mean?
Researchers using data from the Gaia sky survey have identified a gas giant not far from Earth, (a paltry 330 light years away), that puts Jupiter to shame. How? Well, do you remember the ratio I mentioned above – the one where Jupiter has a radius 11 X that of the Earth? This is what that would look like if you could see it:
Well, this new planet, known as 2MASS 1155–7919 b, is roughly the same ratio bigger . . . roughly ten times the size. And the thing is, 2MASS is a babe in the planetary sense, as it orbits a star thought to be only around five million years old. By comparison, our Sun is thought to be over 4.6 billion years old.
The dim, cool object we found is very young and only 10 times the mass of Jupiter, which means we are likely looking at an infant planet, perhaps still in the midst of formation,” said Annie Dickson-Vandervelde, lead author of the survey. “Though lots of other planets have been discovered through the Kepler mission and other missions like it, almost all of those are ‘old’ planets. This is also only the fourth or fifth example of a giant planet so far from its ‘parent’ star, and theorists are struggling to explain how they formed or ended up there.”
Now, what’s exciting about this is the discovery affords astronomers the rare opportunity to observe a gas giant in its formative years. In Jupiter’s case, astronomers are still unraveling just how instrumental our “king” planet was in the formation of the rest of the Solar System, the Main Asteroid Belt, and even the Earth itself. 2MASS is still growing. Who knows how it might influence its neighbors as it matures?
I guess we’ll have to wait and see. But remember, its rare chance encounters like this that not only deepen our understanding of the cosmos, but of life as we know it. Who knows what we might uncover as the years pass by?
Until then . . . “Long live the King!”