 | | | Switch to: Europe, USA, New Zealand, Antarctica Credit: NOAA/Ovation  Planetary K-index
Now: Kp= 1.67 quiet
24-hr max: Kp= 1.67 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 6.77 nT
Bz: 0.99 nT north
more data: ACE, DSCOVR
Updated: Today at 1146 UT Coronal Holes: 25 Dec 23 
There are no significant coronal holes on the Earthside of the sun. 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. 24, 2023, the Arctic stratosphere is warming but still 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. 22, 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 25 2200 UTC FLARE | 0-24 hr | 24-48 hr | CLASS M | 30 % | 30 % | 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 25 2200 UTC Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 05 % | 25 % | MINOR | 01 % | 10 % | SEVERE | 01 % | 01 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 15 % | 15 % | MINOR | 20 % | 20 % | SEVERE | 10 % | 20 % | | | |  | | | | | | | | | | | 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. | | | A CME IS COMING: Yesterday, Dec. 24th, a magnificant filament of magnetism erupted from the sun's northern hemisphere, hurling a CME into space. Most of the CME is expected to pass north of our planet--most, but not all. NASA models suggest a glancing blow on Dec. 27th. Minor G1-class geomagnetic storms are possible on that date. CME impact alerts: SMS Text RECORD-COLD WEATHER IN THE STRATOSPHERE: Now we know why polar stratospheric clouds (PSCs) have suddenly exploded. According to NASA's MERRA-2 climate model, temperatures in the Arctic stratosphere just hit a 40-year record low for the month of December: 
Cold air in the stratosphere is exactly what PSCs require. Normally, the stratosphere has no clouds at all. But when the temperature drops to a staggeringly-low -85 C, widely-spaced water molecules coalesce into ice crystals and PSCs begin to form. Their aurora-like colors make them the most beautiful clouds on Earth. PSCs are normally confined to the Arctic where the stratosphere is coldest. During this week's extreme cold wave, the clouds descended all the way to mid-latitudes. Here they are over Locarno,Switzerland (+46N): 
"I saw these clouds for the first time on Dec. 22nd," says photographer Branca Cristina. "The colors were amazing!" At the same time, the clouds were sighted in Torun, Italy (+45N); the next morning they appeared again in Lausanne, Switzerland (+47N). These are extraordinary excursions from normal PSC habitat. The season for PSCs usually starts in January. The current cold wave has given the season an early start, and could herald many more PSCs in the weeks ahead. To help sky watchers catch these rare clouds, we will henceforth publish daily predictions of temperatures in the Arctic stratosphere. When the air temperature drops below the "Type II PSC" green line, it's time to look for PSCs. Check out the forecast here. Realtime Space Weather Photo Gallery
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Realtime Aurora Photo Gallery
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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 23, 2023, the network reported 1 fireball.
(1 sporadic)  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 25, 2023 there were 2349 potentially hazardous asteroids.
 | Recent & Upcoming Earth-asteroid encounters: | Asteroid | Date(UT) | Miss Distance | Velocity (km/s) | Diameter (m) | | 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 | | 2020 YO3 | 2023-Dec-23 | 0.6 LD | 16.4 | 42 | | 2023 XN10 | 2023-Dec-23 | 18.4 LD | 9.9 | 65 | | 2023 XD18 | 2023-Dec-23 | 3.9 LD | 11 | 17 | | 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 | 11.8 LD | 18.7 | 28 | | 2023 YT | 2023-Dec-25 | 6.1 LD | 4.4 | 20 | | 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 | 39 | | 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 | 15.8 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. Always check your local laws before playing with real money.. | | BestCSGOGambling is the best site for everything related to CSGO gambling on the web | | | These links help Spaceweather.com stay online. Thank you to our supporters! | | | | | | | | |  | | |  | ©2021 Spaceweather.com. All rights reserved. This site is penned daily by Dr. Tony Phillips. | |
