Equinox Auroras, Ancient Stars, and a Satellite Resurrection

It's the first day of astronomical spring — and the universe is celebrating in style. On today's Astronomy Daily, Anna and Avery cover a triple CME solar storm with aurora potential reaching as far south as Illinois, explain why the vernal equinox amplifies aurora activity, report on the ongoing meteorite hunt following Tuesday's spectacular Ohio fireball, reveal an extraordinary 14-billion-year-old star that carries the chemical fingerprints of the universe's very first stars, bring a happy update on Europe's Proba-3 solar science satellite which has ended a month of silence, and explain how X-ray CT scans of returned asteroid samples finally cracked one of Bennu's longest-standing mysteries. Stories in This Episode 1. Triple CME Strike + Equinox Aurora Alert Three coronal mass ejections (CMEs) are currently en route to Earth, with the first arriving today. Forecasters predict G2 (moderate) to G3 (strong) geomagnetic storm conditions, potentially bringing auroras as far south as Illinois. The timing coincides with the vernal equinox — historically one of the best aurora windows of the year due to the Russell-McPherron effect. 2. The Vernal Equinox — Today! The 2026 March equinox arrived today at 14:46 UTC, marking the astronomical start of spring in the Northern Hemisphere (and autumn in the Southern). Tonight, a thin crescent Moon appears alongside Venus in the west-southwest sky. 3. Ohio Fireball — Meteorite Hunt Underway On St. Patrick's Day (March 17), a seven-ton asteroid exploded over northeast Ohio with the force of 250 tons of TNT. NASA confirmed meteorites landed near Medina County, and hunters from across the US have already found fragments in the Sharon Center area. 4. Ancient 'Cosmic Fossil' Star PicII-503 Astronomers have discovered PicII-503, a second-generation star in the Pictor II dwarf galaxy with only 1/40,000th of the Sun's iron — the lowest ever measured outside the Milky Way. Its extraordinary carbon-to-iron ratio links it to mysterious carbon-enhanced metal-poor stars scattered across our galaxy's halo, solving a long-standing stellar mystery. Published in Nature Astronomy by Anirudh Chiti (Stanford) et al. 5. Proba-3 Phones Home — 'A Great Relief!' ESA confirmed on March 19 that its Proba-3 Coronagraph satellite — silent since mid-February after an anomaly caused it to lose attitude control — has reestablished contact via the Villafranca ground station. The spacecraft is in safe mode, solar-powered, and undergoing health checks before science operations can resume. 6. NASA Cracks Bennu's Boulder Mystery X-ray CT scans of returned OSIRIS-REx samples reveal Bennu's boulders are riddled with internal crack networks — the missing piece explaining the asteroid's puzzling low thermal inertia. Published in Nature Communications. The findings will improve asteroid characterisation from Earth-based telescopes globally. Source Links Triple CME / Aurora Alert — Space.com: https://www.space.com/stargazing/auroras/aurora-alert-powerful-geomagnetic-storm-could-spark-northern-lights-as-far-south-as-illinois-on-march-19 (https://www.space.com/stargazing/auroras/aurora-alert-powerful-geomagnetic-storm-could-spark-northern-lights-as-far-south-as-illinois-on-march-19) Triple CME / Sun News — EarthSky: https://earthsky.org/sun/sun-news-activity-solar-flare-cme-aurora-updates/ (https://earthsky.org/sun/sun-news-activity-solar-flare-cme-aurora-updates/) NOAA Space Weather Prediction Centre: https://www.spaceweather.gov (https://earthsky.org/astronomy-essentials/everything-you-need-to-know-vernal-or-spring-equinox/ (https://earthsky.org/astronomy-essentials/everything-you-need-to-know-vernal-or-spring-equinox/) Ohio Fireball — EarthSky: https://earthsky.org/earth/sonic-boom-from-a-meteor-cleveland-ohio-and-pennsylvania-mar-17-2026/ (https://earthsky.org/earth/sonic-boom-from-a-meteor-cleveland-ohio-and-pennsylvania-mar-17-2026/) Ohio Meteorite Hunt — Cleveland19: https://www.cleveland19.com/2026/03/19/meteorite-hunters-states-away-find-fragments-northeast-ohio/ (https://www.cleveland19.com/2026/03/19/meteorite-hunters-states-away-find-fragments-northeast-ohio/) PicII-503 Discovery — NOIRLab: https://noirlab.edu/public/news/noirlab2607/ (https://noirlab.edu/public/news/noirlab2607/) PicII-503 — Nature Astronomy (DOI): https://doi.org/10.1038/s41550-026-02802-z (https://doi.org/10.1038/s41550-026-02802-z) Proba-3 Phones Home — Space.com: https://www.space.com/space-exploration/missions/a-great-relief-europes-proba-3-solar-eclipse-satellite-phones-home-after-a-month-of-silence (https://www.space.com/space-exploration/missions/a-great-relief-europes-proba-3-solar-eclipse-satellite-phones-home-after-a-month-of-silence) Proba-3 ESA Statement: https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba-3_s_Coronagraph_is_alive (https://www.esa.int/Enabling_Support/Space_Engineering_Technology/Proba-3_s_Coronagraph_is_alive) Bennu...