In the midst of gathering darkness, light becomes more evident.

In the midst of gathering darkness, light becomes more evident.

BONNIE BOSTROM Sailing through the Cosmos, a true story, as we sailed in an area of much bioluminescence, on a calm and clear night, we could not tell the difference between the stars and planets above and the bioluminescent below. What a lot of people don't know that on a very dark and clear night, one can see different colors of planets, and the bioluminescent also is a variety of colors. View all Mercury: gray (or slightly brownish). ... Venus: pale yellow. ... Earth: mostly blue with white clouds. ... Mars: mostly reddish brown, though with some darker regions, and also white ice caps. ... Jupiter: orange and white bands. ... Saturn: pale gold. ... Uranus: pale blue. ... Neptune: pale blue... Space is full of planets, and most of them don't even have stars. Here in the Solar System, we can watch our star's eight planets orbit with confidence, knowing full well that we've discovered at least the majority of round, orbit-clearing worlds around our Sun. But there's a 4.5 billion year history that we can't fully know from our vantage point today. All we can be certain of are which planets have survived until now. What about the worlds that were formed around our Sun early on, and then ejected by some violent gravitational process? What about the worlds that would have been planets had they only formed around a star, rather than in the abyss of interstellar space? Over the past few years, we've begun to find these orphan planets — sometimes called rogue planets — in the spaces between stars. Based on what we know of stars, gravity, and cosmic evolution, we can make a ballpark estimate of the total number of planets in the Universe, and it likely outnumbers our stars by anywhere from a factor of 100 to 100,000. Space is full of planets, and most of them don't even have stars.