Greek mythology has given a name to a great many objects in our solar system. But perhaps one of the least well understood are the Trojans, named after the people of Troy featured in “The Iliad.” When astronomers refer to them, they are normally talking about a group of more than 10,000 confirmed asteroids orbiting at the Lagrange points both in front of and behind Jupiter on its orbit around the sun.

Two microscopic grains collide and produce a tiny spark. This phenomenon may have provided the energy to kick off life on Earth. But if these solid particles have the same composition, what factor causes the charge to flow in a given direction? In a study published in Nature, physicists from the Institute of Science and Technology Austria (ISTA) identify the key factor as environmental carbon-based molecules that adhere to the materials’ surface.

Two recent studies suggest that fiber-optic cables laid directly on the moon’s surface could potentially detect moonquakes, offering a simpler way to gather seismic data to support future human and robotic exploration.

For decades, astronomers have struggled to differentiate giant planets from brown dwarfs, a class of objects more massive than planets but too small to ignite nuclear fusion like true stars. Through a telescope, these cosmic lookalikes can have overlapping brightness, temperatures, and even atmospheric fingerprints. The striking similarity leaves astronomers unsure if they have observed an oversized planet or an undersized star. Now, a Northwestern University-led team has uncovered a crucial clue that separates the two: how fast they spin.