What Would Happen If the Sun Went Out for a Week?

What would really happen if the Sun simply switched off for exactly one week, and then came back? We follow it minute by minute, hour by hour and day by day: the eight minutes when nobody on Earth knows, the moment the whole planet is in night at once, the planets going out one by one, the freeze that hits the middle of America first, what breaks in the cities, and what keeps breaking after the light comes back. And the strangest part: the Sun could never actually do this, and the first warning would come from detectors buried deep underground. This is a thought experiment. In our story the Sun keeps its mass, so Earth's orbit does not change. No published climate model has run this exact scenario, so the day-by-day temperatures are our own energy-balance estimates, anchored to real cooling rates (total eclipses, polar night at Vostok, Winter Storm Uri). Every other number comes from NASA, NOAA, the US Energy Information Administration and published science. Where it is a model or our own rough arithmetic, we say so. 0:00 The Sun goes out for a week 1:19 The rules: no light, same gravity 1:53 Minute 0: nobody knows 2:43 Minute 8: darkness arrives 4:15 Hour 1: planets, satellites and the grid 6:18 Hour 6: the heat leaves 7:18 Day 1: the endless night 8:15 Day 2: the hard freeze 9:22 Day 3: pipes, gas and the grid 11:05 Day 4: storms on every coast 12:11 Day 5: January in October 13:14 Day 6: the coldest place on Earth 14:03 Day 7: the last day 15:01 Day 8: the Sun comes back 16:19 One month later: the harvest 18:11 What if it never came back? 19:10 The strangest part: the Sun can't switch off 20:20 The early warning: neutrinos 21:43 The real danger KEY SOURCES IAU 2012 astronomical unit (light time 499.0 s); light-travel times to the planets: our calculation NASA GLOBE Observer, 2017 eclipse air-temperature data; Galen et al. 2018 (Annals of the Entomological Society of America), bees during the 2017 eclipse; Aguilar et al. 2025 (Science), birds during the 2024 eclipse US Energy Information Administration: Electric Power Monthly (solar share), Today in Energy (2024 eclipse, Winter Storm Uri gas production, storage and consumption records) NASA NTRS 20170004112 (ISS lithium-ion batteries); NASA CERES (outgoing longwave radiation); NASA TSIS-1 (total solar irradiance) Turner et al. 2009 (Journal of Geophysical Research), the Vostok −89.2°C record; NOAA State Climate Extremes Committee Texas DSHS (Winter Storm Uri deaths), ERCOT; Perryman Group 2021 (Uri cost projection) Purdue and NC State extension (corn frost), Kansas State and Washington State (winter wheat), Kansas State / Ohio State extension (cattle cold stress); University of Illinois Building Research Council (frozen pipes); NWS wind chill chart Grossman & Betts 1990 (cold-air outbreak heat fluxes); van de Poll et al. 2019 (Limnology & Oceanography), phytoplankton in darkness Zhao et al. 2021 (Lancet Planetary Health), cold- and heat-related deaths; FAO cereal stocks (Nov 2025) US National Park Service, 1816 "Year Without a Summer"; Easter freeze 2007 (Illinois State Water Survey, HortScience 2008); 1975 Brazil frost David Stevenson (Caltech), estimates for a Sun that never comes back; Davies & Davies 2010 (Solid Earth), Earth's internal heat flow; WHOI, 1977 Galápagos hydrothermal vents (Alvin) NASA Goddard SVS and NASA SOHO (energy travel time from the core); Kelvin–Helmholtz timescale; Borexino Collaboration 2020 (Nature), CNO neutrinos; Super-Kamiokande; Supernova 1987A neutrinos (Kamiokande-II, IMB, Baksan) NASA Parker Solar Probe (closest approach, 24 Dec 2024) Our own estimates (labelled in the video): temperatures by day, ocean cooling, unheated-house cooling, satellite battery times. FOOTAGE & IMAGERY Stock footage: Pexels and Pixabay (free licenses). Footage is illustrative. 3D animations: our own renders from NASA Blue Marble Next Generation, NASA Black Marble and NASA LRO Moon imagery (public domain); the Sun, planets and the Sun's interior are illustrations, not to scale. NASA does not endorse this video. Maps: Natural Earth (public domain). All charts and animations: The Day After. No AI-generated images or video were used in the video itself.