| | Switch to: Europe, USA, New Zealand, Antarctica Credit: NOAA/Ovation Planetary K-index Now: Kp= 1.67 quiet 24-hr max: Kp= 4.00 unsettled explanation | more data Interplanetary Mag. Field Btotal: 4.08 nT Bz: -0.96 nT south more data: ACE, DSCOVR Updated: Today at 1146 UT Coronal Holes: 20 Dec 23 Earth is inside a stream of solar wind flowing from this coronal hole. Credit: SDO/AIA Polar Stratospheric Clouds Colorful Type II polar stratospheric clouds (PSC) form when the temperature in the stratosphere drops to a staggeringly low -85C. NASA's MEERA-2 climate model predicts when the air up there is cold enough: On Dec. 20, 2023, the Arctic stratosphere is cold enough for polar stratospheric clouds. Sky watchers inside the Arctic Circle should be alert for their intense colors | more data. Noctilucent Clouds The southern season for NLCs is underway. The first clouds were detected inside the Antarctic Circle on Dec. 4th by the NOAA 21 satellite. An instrument onboard NOAA 21 (OMPS LP) is able to detect NLCs (also known as "polar mesospheric clouds" or PMCs). For the rest of the season, daily maps from NOAA 21 will be presented here: Updated: Dec. 20, 2023 Each dot is a detected cloud. As the season progresses, these dots will multiply in number and shift in hue from blue to red as the brightness of the clouds intensifies. SPACE WEATHER NOAA Forecasts | | Updated at: 2023 Dec 20 2200 UTC FLARE | 0-24 hr | 24-48 hr | CLASS M | 35 % | 35 % | CLASS X | 05 % | 05 % | Geomagnetic Storms: Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm Updated at: 2023 Dec 20 2200 UTC Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 15 % | 10 % | MINOR | 05 % | 01 % | SEVERE | 01 % | 01 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 15 % | 15 % | MINOR | 15 % | 15 % | SEVERE | 10 % | 10 % | | | | | | | | | | | | This is an AI Free Zone! Text created by ChatGPT and other Large Language Models is spreading rapidly across the Internet. It's well-written, artificial, frequently inaccurate. If you find a mistake on Spaceweather.com, rest assured it was made by a real human being. | | | COMING SOON--AN EARTH-DIRECTED FLARE: Now turning to face Earth, sunspot AR3529 is growing rapidly (movie), and it has a 'beta-gamma' magnetic field that poses a threat for strong M-class solar flares. Geoeffective explosions are likely this week. CME alerts: SMS Text MORE POLAR STRATOSPHERIC CLOUDS: For the third day in a row, Arctic sky watchers are reporting a widespread outbreak of polar stratospheric clouds. "The colors are spectacular," says Ramune Sapailaite, who photographed the display over Gran, Norway: "The clouds were visible in the sky all day, but the colors really exploded just before sunset," says Sapailaite. "I took these pictures using my cellphone." Widely considered to be the most beautiful clouds on Earth, polar stratospheric clouds (PSCs) are rare. Earth's stratosphere is very dry and, normally, it has no clouds at all. PSCs form when the temperature in the Arctic stratosphere drops to a staggeringly-low -85 C. Then, and only then, can widely-spaced water molecules begin to coalesce into tiny ice crystals. High-altitude sunlight shining through the crystals creates intense iridescent colors that rival auroras. During a typical Arctic winter, PSCs appear no more than a handful of times, and the first sightings usually come in January. This week's apparition marks an early start, and may herald many more PSCs to come. Something new: For the rest of this northern winter season, we will publish daily predictions of temperatures in the Arctic stratosphere. This will help sky watchers know when to look for these rare clouds. The predictions are right here. more images: from Alan C. Tough of Elgin, Moray, Scotland Realtime Space Weather Photo Gallery Free: Spaceweather.com Newsletter CHRISTMAS GIFTS FROM THE EDGE OF SPACE: Are you looking for a far-out Christmas gift? Check out the Earth to Sky Store. It's filled with unique items that have flown to the edge of space onboard cosmic ray research balloons. Carried aloft by giant helium balloons, these unique gifts have flown above 99.7% of Earth's atmosphere, experiencing space-like blasts of cosmic rays, extreme cold, and a wild ride parachuting back to Earth after the balloon explodes. Even Amazon doesn't carry items this far out. Don't forget to enter coupon code "BUZZALDRIN" at checkout for a 10% holiday discount. Far Out Gifts: Earth to Sky Store All sales support hands-on STEM education Realtime Aurora Photo Gallery Free: Spaceweather.com Newsletter Realtime Comet Photo Gallery Free: Spaceweather.com Newsletter Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. Daily results are presented here on Spaceweather.com. On Dec 20, 2023, the network reported 12 fireballs. (10 sporadics, 1 December Leonis Minorid, 1 Comae Berenicid) In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies] Potentially Hazardous Asteroids ( PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time. On December 20, 2023 there were 2349 potentially hazardous asteroids. | Recent & Upcoming Earth-asteroid encounters: Asteroid | Date(UT) | Miss Distance | Velocity (km/s) | Diameter (m) | 2023 XN15 | 2023-Dec-15 | 1.9 LD | 19.5 | 17 | 2023 XZ11 | 2023-Dec-15 | 3.7 LD | 14.7 | 33 | 2023 WV23 | 2023-Dec-15 | 5.2 LD | 6.6 | 60 | 2023 XL4 | 2023-Dec-15 | 11.4 LD | 6.6 | 22 | 2023 XK10 | 2023-Dec-15 | 17.7 LD | 13.6 | 44 | 2023 XY2 | 2023-Dec-15 | 9.7 LD | 13.4 | 35 | 2023 XU12 | 2023-Dec-15 | 12.7 LD | 4.7 | 14 | 2023 XK4 | 2023-Dec-15 | 3.4 LD | 4.2 | 15 | 2023 XG18 | 2023-Dec-15 | 2.1 LD | 14 | 8 | 2023 XV2 | 2023-Dec-15 | 15.9 LD | 6.5 | 23 | 2023 XS14 | 2023-Dec-15 | 8 LD | 14.8 | 26 | 2023 XJ13 | 2023-Dec-16 | 9.7 LD | 9.2 | 14 | 2023 XJ10 | 2023-Dec-17 | 8.3 LD | 16.1 | 28 | 2023 XL14 | 2023-Dec-17 | 1.5 LD | 6.3 | 9 | 2023 XH1 | 2023-Dec-17 | 15.2 LD | 5.4 | 17 | 2023 YY | 2023-Dec-17 | 14.7 LD | 6.7 | 40 | 2023 XA14 | 2023-Dec-17 | 10.7 LD | 5.4 | 12 | 2023 XL11 | 2023-Dec-18 | 6.2 LD | 11.7 | 17 | 2023 YS | 2023-Dec-19 | 5.3 LD | 31.5 | 27 | 2023 XF2 | 2023-Dec-19 | 9.8 LD | 8 | 22 | 2016 XD2 | 2023-Dec-19 | 18.8 LD | 6.9 | 59 | 2023 YO | 2023-Dec-19 | 4.6 LD | 4.3 | 7 | 2023 XS | 2023-Dec-19 | 11.5 LD | 9.1 | 31 | 341843 | 2023-Dec-20 | 16.5 LD | 5.3 | 344 | 2023 YB | 2023-Dec-21 | 8.8 LD | 11.2 | 28 | 2018 YJ2 | 2023-Dec-21 | 18.4 LD | 13.1 | 154 | 2022 YG | 2023-Dec-22 | 11.2 LD | 5.1 | 17 | 2023 VD6 | 2023-Dec-23 | 10.6 LD | 15.5 | 159 | 2023 YP | 2023-Dec-23 | 0.9 LD | 7.7 | 9 | 2023 XN10 | 2023-Dec-23 | 18.4 LD | 9.9 | 65 | 2023 XD18 | 2023-Dec-23 | 3.9 LD | 11 | 17 | 2020 YO3 | 2023-Dec-23 | 3.6 LD | 16.6 | 42 | 2023 XN11 | 2023-Dec-24 | 9.3 LD | 10.4 | 42 | 2010 UE51 | 2023-Dec-24 | 9 LD | 1.3 | 7 | 2023 XP13 | 2023-Dec-24 | 11.9 LD | 18.7 | 28 | 2023 YT | 2023-Dec-25 | 6.1 LD | 4.4 | 21 | 2023 XK16 | 2023-Dec-25 | 8.7 LD | 7.4 | 38 | 2020 YR2 | 2023-Dec-25 | 13.8 LD | 8 | 8 | 2023 XJ3 | 2023-Dec-25 | 16.5 LD | 9.2 | 55 | 2020 KT4 | 2023-Dec-25 | 13.4 LD | 7.3 | 76 | 2023 XO7 | 2023-Dec-26 | 6.3 LD | 6.7 | 23 | 2023 YD | 2023-Dec-28 | 1.6 LD | 9.9 | 29 | 2023 YZ | 2023-Dec-29 | 10 LD | 5.6 | 29 | 2023 YM | 2023-Dec-30 | 10.1 LD | 12.4 | 37 | 2023 XE12 | 2023-Dec-31 | 14.7 LD | 11.8 | 42 | 2021 AM6 | 2023-Dec-31 | 18.3 LD | 6.6 | 17 | 2023 YR | 2024-Jan-02 | 4.5 LD | 12.2 | 40 | 2019 KK5 | 2024-Jan-03 | 10.6 LD | 20.9 | 98 | 2002 AY1 | 2024-Jan-08 | 15.2 LD | 17.3 | 230 | 2023 XN13 | 2024-Jan-09 | 15.7 LD | 1.4 | 8 | 2023 XT14 | 2024-Jan-10 | 12.2 LD | 6.4 | 27 | 2020 AC1 | 2024-Jan-11 | 19.3 LD | 5.3 | 7 | 2023 WZ3 | 2024-Jan-11 | 16.1 LD | 4 | 35 | 2021 CZ2 | 2024-Jan-16 | 8 LD | 14.3 | 113 | 2021 BL3 | 2024-Jan-23 | 17.2 LD | 23.4 | 41 | 2017 BG92 | 2024-Jan-25 | 11.8 LD | 6.3 | 6 | 2011 CQ1 | 2024-Jan-26 | 11.3 LD | 4.6 | 1 | 2007 EG | 2024-Jan-30 | 16 LD | 8.6 | 43 | 2008 OS7 | 2024-Feb-02 | 7.5 LD | 18.2 | 285 | 2019 CC5 | 2024-Feb-04 | 19.2 LD | 15 | 139 | 2023 SP1 | 2024-Feb-07 | 14.3 LD | 11.8 | 256 | 2020 DK | 2024-Feb-12 | 8.9 LD | 9.9 | 22 | Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. | Cosmic Rays in the Atmosphere | SPACE WEATHER BALLOON DATA: Almost once a week, Spaceweather.com and the students of Earth to Sky Calculus fly space weather balloons to the stratosphere over California. These balloons are equipped with sensors that detect secondary cosmic rays, a form of radiation from space that can penetrate all the way down to Earth's surface. Our monitoring program has been underway without interruption for 7 years, resulting in a unique dataset of in situ atmospheric measurements. Latest results (July 2022): Atmospheric radiation is decreasing in 2022. Our latest measurements in July 2022 registered a 6-year low: What's going on? Ironically, the radiation drop is caused by increasing solar activity. Solar Cycle 25 has roared to life faster than forecasters expected. The sun's strengthening and increasingly tangled magnetic field repels cosmic rays from deep space. In addition, solar coronal mass ejections (CMEs) sweep aside cosmic rays, causing sharp reductions called "Forbush Decreases." The two effects blend together to bring daily radiation levels down. .Who cares? Cosmic rays are a surprisingly "down to Earth" form of space weather. They can alter the chemistry of the atmosphere, trigger lightning, and penetrate commercial airplanes. According to a study from the Harvard T.H. Chan school of public health, crews of aircraft have higher rates of cancer than the general population. The researchers listed cosmic rays, irregular sleep habits, and chemical contaminants as leading risk factors. A number of controversial studies (#1, #2, #3, #4) go even further, linking cosmic rays with cardiac arrhythmias and sudden cardiac death. Technical notes: The radiation sensors onboard our helium balloons detect X-rays and gamma-rays in the energy range 10 keV to 20 MeV. These energies span the range of medical X-ray machines and airport security scanners. Data points in the graph labeled "Stratospheric Radiation" correspond to the peak of the Regener-Pfotzer maximum, which lies about 67,000 feet above central California. When cosmic rays crash into Earth's atmosphere, they produce a spray of secondary particles that is most intense at the entrance to the stratosphere. Physicists Eric Regener and Georg Pfotzer discovered the maximum using balloons in the 1930s and it is what we are measuring today. | The official U.S. government space weather bureau | | The first place to look for information about sundogs, pillars, rainbows and related phenomena. | | Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. | | 3D views of the sun from NASA's Solar and Terrestrial Relations Observatory | | Realtime and archival images of the Sun from SOHO. | | information about sunspots based on the latest NOAA/USAF Active Region Summary | | current counts of failed and deployed Starlink satellites from Jonathan's Space Page | | Authoritative predictions of space junk and satellite re-entries | | from the NOAA Space Environment Center | | fun to read, but should be taken with a grain of salt! Forecasts looking ahead more than a few days are often wrong. | | from the NOAA Space Environment Center | | the underlying science of space weather | | When looking for casinos to play online when the weather is bad, you can try the SkyCity Online Casino if you are located in New Zealand. If you are not from NZ you can try the Swedish page Svenska casino online to find suitable games, check out svenskacasinoonline.net. 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