The faraway exoplanet could help provide answers as to why there are hardly any planets with twice the diameter of Earth.

Earth is our home planet, and it's the only place in the universe where we know for certain that life exists. Earth formed over 4.5 billion years ago from a swirling cloud of gas and dust squished ...

Of course, this is only from our perspective of the cosmos on Earth — in reality the planets remain extremely far apart. These conjunctions aren't rare, but they get rarer with each planet added ...