"It's like a game of billiards around the solar system, flying by a couple of planets at just the right angle and timing to ...

Stargazers will be treated to a rare alignment of seven planets on 28 February when Mercury joins six other planets that are already visible in the night sky. Here's why it matters to scientists.

The answer is no. Each planet orbits the sun at a slightly different inclination, ranging from .8° for Uranus to 7° for Mercury. Earth is a special case; its inclination is 0° because it defines the ...

Despite the name, a planetary alignment isn’t when the planets get in a row, it’s when a fair few gather on one side of the ...

But we're yet to prove that, not in small part because of our inability to directly observe the rocky planets residing in their solar system's habitable zones. A habitable zone is a rather small ...