Hubble has revealed an evolving 10-sided atmospheric wave around Saturn’s south pole. Learn what scientists know, how jet-stream waves can form polygonal patterns, and why the decagon differs from Saturn’s famous northern hexagon.
Earth’s seasons are caused mainly by its tilted axis, not its changing distance from the Sun. Learn how solar angle and day length change through solstices and equinoxes.
Learn how the Cocoon Nebula can be an emission, reflection and dark nebula at the same time, why dust hides stars, and how dense clouds form new stars.
Learn how lunar impact craters form, why fresh ejecta looks bright, how secondary craters develop, and how NASA’s LRO finds new impacts by comparing before-and-after images.
Learn how GX 301-2 captures part of Wray 977’s stellar wind, how temporary accretion forms, and how XRISM spectroscopy revealed plasma falling toward the pulsar.
What is a brown dwarf? Webb has identified objects in IC 348 with masses around twice Jupiter's, helping astronomers test how the smallest star-like bodies form.
NASA has activated Roman's 300-megapixel Wide Field Instrument in space. Learn how its 18 detectors, wide field of view and infrared sensitivity enable enormous astronomical surveys.
Mercury is relatively close to Earth, yet placing a spacecraft in orbit there is extraordinarily difficult. Here is how BepiColombo uses gravity assists, efficient propulsion and careful braking to arrive.
Learn why auroras glow green, red, blue, pink and purple, how oxygen and nitrogen create the colours, and why auroras can be more active near equinoxes.
Learn what an analemma is, why the Sun traces a figure eight over a year, and how Earth’s axial tilt, elliptical orbit, solstices and equinoxes create the pattern.
The equinox is often described as the day of 12 hours of daylight and 12 hours of darkness. In reality, the Sun’s visible disc, atmospheric refraction and latitude make the balance only approximate.
Learn how lunar impact craters form, what ejecta and regolith are, how NASA found the fresh McGetchin crater, and why its surrounding cold spot matters.