The Moon takes aim at the heart of the scorpion tonight — the bright star Antares. It’s below the Moon at nightfall, but closer to the left of the Moon as they set, in the wee hours of the morning.
The region around Antares is filled with young stars. Many of them, like Antares, are big and bright. And the region also may be filled with planets. A recent study reported dozens of possible “rogue” planets — worlds that don’t orbit a star.
Because they’re far away from any stars, the free-floating planets reflect almost no starlight, making them faint. But the planets are young, so they’re still warm. That means they produce a glow of their own, mainly at red and infrared wavelengths. Astronomers discovered the possible planets by analyzing 20 years of observations by telescopes on the ground and in space.
It took some careful work to pick out the planets. But the astronomers reported finding about 70 planets that were roughly as massive as Jupiter, the giant of our own solar system. And they found as many as a hundred more objects that could also be planets.
The planets could have formed as a cloud of gas and dust that was too small to make stars collapsed to form smaller bodies. On the other hand, the planets could have been born around stars, then kicked away by encounters with other planets. Or perhaps there’s some other explanation for the wayward planets in that busy region of the galaxy.