A Rare Comet's Plasma Tail Is About to Slam Earth — And The Timing Couldn't Be Worse The Space Desk and The Sky Lab

A rare long-period comet, C/2025 R3 PANSTARRS, is about to have its plasma tail sweep past Earth's orbital path on April 25-26, 2026 — and it's arriving in the same 48-hour window as a flare-productive sunspot region, a high-speed coronal hole stream, and the ongoing aftershock sequence from Japan's April 20 M7.4 earthquake. The last time a spacecraft directly measured a long-period comet's plasma tail at Earth-orbit distances was Ulysses at Hyakutake in 1996 — entirely by accident. This time we know it's coming, and ACE, DSCOVR, and STEREO-A are all positioned to see it. Here's what the science actually says versus what's going viral online.