Comet

"Dead stars" known as white dwarfs have already shown the potential to help us better understand how planetary systems, including our own solar system, take shape and evolve. Now, research from the University of Michigan and the University of Colorado Boulder suggests that potential could be even greater than anticipated.

Typically, astronomers identify comets by their distinct atmospheres, or comae, and their tails, which are created as the sun vaporizes a comet's ice. These features emit a glow when sunlight bounces off dust and water droplets. As gas escapes the body of the comet, it also acts as a tiny thruster, subtly changing the comet's path.

Like a shelf in an old house, the Earth collects a lot of dust from its surroundings. This "space dust" is mostly made up of micrometeorites that survive atmospheric entry and provides researchers with a cheap and easy way to obtain samples to study our cosmic neighbors. However, it can be difficult to determine which objects certain samples originated from if their parent bodies aren't already in available catalogs. A recent study, published in Science Advances, describes a new subset of space […]

Last year, an interstellar traveler entered our solar system. Some speculated that it was an alien spacecraft, but it turned out to be a comet, 3I/Atlas, and it provoked interest from astronomers and astrophysicists eager for insights into galaxies far, far away. Detailed observations from the National Aeronautics and Space Administration (NASA) shot down the alien spacecraft idea, but recent NASA analysis holds clues about the comet's ancient and, literally, alien origins.

Astronomers have used the European Southern Observatory's Very Large Telescope (ESO's VLT) to study the composition of 3I/ATLAS, the brightest interstellar object ever seen, in detail. By measuring specific chemical fingerprints—the first observations of this kind for a comet that formed outside the solar system—they found that 3I/ATLAS likely originated in the outskirts of an old star system.