ACA Awards

  Plasma ejections from young stars may offer valuable insights into the Sun’s early history. Most of the time, we hardly notice it from Earth, but the Sun is constantly hurling vast clouds of charged plasma into space. These eruptions, known as coronal mass ejections (CMEs), often accompany sudden bursts of light called solar flares. When these energetic events reach far enough to interact with Earth’s magnetic field, they can create space weather, producing dazzling auroras, triggering geomagnetic storms, and in rare cases, disrupting power grids. Scientists think that billions of years ago, when both the Sun and Earth were young, this solar activity was far more intense. The early Sun may have unleashed CMEs so powerful that they influenced how life first appeared and evolved on our planet. Studies of young, Sun-like stars, which serve as stand-ins for our own star’s early days, show that they frequently generate flares far stronger than any recorded in modern times. Massive CME...

  A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than the hypothesized Planet Nine. According to a new measurement of the Kuiper Belt plane – the vast ring of icy worlds wherein Pluto resides – an unexpected 15-degree tilt in the orbital alignment of some objects in the belt could be the result of the influence of a planet stirring up trouble. "One explanation is the presence of an unseen planet, probably smaller than the Earth and probably bigger than Mercury, orbiting in the deep outer Solar System," astrophysicist Amir Siraj of Princeton University told CNN. "This paper is not a discovery of a planet, but it's certainly the discovery of a puzzle for which a planet is a likely solution." It's actually incredibly difficult to see what lies beyond the orbit of Neptune. So far from the Sun, the small objects in the flattened, donut-shaped Kuiper Belt reflect very little sunlight; they...