 | | |  Solar wind
speed: 457.1 km/sec
density: 2.50 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1145 UT X-ray Solar Flares
6-hr max: C4 2245 UT Dec20
24-hr: M2 1118 UT Dec20
explanation | more data
Updated: Today at: 2350 UT  Daily Sun: 20 Dec 24 Expand: labels | no labels | Carrington
Sunspots 3922, 3924 and 3927 *all* have 'beta-gamma' magnetic fields that pose a threat for M-class solar flares. Photo credit: Ivo Demeulenaere of Flanders, Belgium
more images: from Germany;
Note: On Nov. 26, 2024, a flood at Stanford University damaged a number of important SDO data servers. Repairs will not be completed until 2025. As a result, for the foreseeable future, Daily Sun images will be coming from readers of Spaceweather.com. Thank you, citizen scientists!  |  | Sunspot number: 96
What is the sunspot number?
Updated 20 Dec 2024
Spotless Days
Current Stretch: 0 days
2024 total: 0 days (0%)
2023 total: 0 days (0%)
2022 total: 1 day (<1%)
2021 total: 64 days (18%)
2020 total: 208 days (57%)
2019 total: 281 days (77%)
2018 total: 221 days (61%)
2017 total: 104 days (28%)
2016 total: 32 days (9%)
2015 total: 0 days (0%)
2014 total: 1 day (<1%)
2013 total: 0 days (0%)
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
2008 total: 268 days (73%)
2007 total: 152 days (42%)
2006 total: 70 days (19%)
Updated 20 Dec 2024
Thermosphere Climate Index
today: 25.36x1010 W Warm
Max: 49.4x1010 W Hot (10/1957)
Min: 2.05x1010 W Cold (02/2009)
explanation | more data: gfx, txt
Updated 19 Dec 2024 The Radio Sun
10.7 cm flux: 175 sfu
explanation | more data
Updated 20 Dec 2024 Cosmic Rays Solar Cycle 25 is intensifying, and this is reflected in the number of cosmic rays entering Earth's atmosphere. Neutron counts from the University of Oulu's Sodankyla Geophysical Observatory show that cosmic rays reaching Earth are slowly declining--a result of the yin-yang relationship between the solar cycle and cosmic rays.
Oulu Neutron Counts
Percentages of the Space Age average:
today: -7.3% Low
48-hr change: +0.6%
Max: +11.7% Very High (12/2009)
Min: -32.1% Very Low (06/1991)
explanation | more data
Updated 20 Dec 2024 @ 0700 UT 
Current Auroral Oval: Switch to: Europe, USA, New Zealand, Antarctica Credit: NOAA/Ovation Planetary K-index
Now: Kp= 3.33 quiet
24-hr max: Kp= 3.67 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 7.10 nT
Bz: 2.89 nT north
more data: ACE, DSCOVR
Updated: Today at 1147 UT Coronal Holes: 20 Dec 24 
Solar wind flowing from this minor coronal hole should reach Earth on Dec. 23-24. It is not big enough to cause a geomagnetic storm. Credit: NOAA/GOES-16 | more data 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 MERRA-2 climate model predicts when the air up there is cold enough: 
On Dec. 20, 2024, the Arctic stratosphere is cold enough for Type I polar stratospheric clouds and almost cold enough for Type II clouds. | more data. Noctilucent Clouds
The southern season for noctilucent clouds (NLCs) is underway!. The first clouds were detected over Antarctica on Nov. 19, 2024. Here is the current NLC map from the NOAA 21 satellite.
Updated: Dec. 18, 2024
An instrument onboard NOAA 21 (OMPS LP) is able to detect NLCs (also known as "polar mesospheric clouds" or PMCs). In the daily map, above, 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: 2024 Dec 20 2200 UTC FLARE | 0-24 hr | 24-48 hr | CLASS M | 65 % | 60 % | CLASS X | 10 % | 10 % | Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm Updated at: 2024 Dec 20 2200 UTC Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 15 % | 10 % | MINOR | 05 % | 05 % | SEVERE | 01 % | 01 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 15 % | 15 % | MINOR | 25 % | 20 % | SEVERE | 25 % | 15 % | | | |  | | | | | | | | | | | This is an AI Free Zone! Text created by Large Language Models is spreading rapidly across the Internet. It's well-written, but frequently inaccurate. If you find a mistake on Spaceweather.com, rest assured it was made by a real human being. | | | THE SOLSTICE IS THIS WEEKEND: The annual December solstice occurs this Saturday, Dec. 21st, at 4:19 a.m. EST. It marks the beginning of winter in the northern hemisphere amd summer in the southern hemisphere. Wherever you live, Happy Solstice! Solar flare alerts: SMS Text "MASSIVE" REENTRY OVER PUERTO RICO: That was no meteor. Last night in the Caribbean, sky watchers watched a bright fireball crawl across the night sky, disintegrating as it fell. "It was MASSIVE," says Desiree Marvin, who video-recorded the display from Dorado Beach, Puerto Rico: "My video time-stamped the event at 11:26 pm local time on Dec. 19th (03:26 UT on Dec. 20th)," says Marvin. Other observers in the Virgin Islands and Grenadines saw the fireball at about the same time. The timing and direction of the fireball are a good match for NORAD object 60467, a Chinese rocket expected to reenter Earth's atmosphere during the early hours of Dec. 20th. If our identification is correct, this was the body of a Long March 4 rocket launched from the Xichang Satellite Launch Center in Sichuan province on Aug. 16, 2024. The rocket's payload is shrouded in mystery. NORAD catalogued 10 objects from the launch (including the rocket that just decayed). The other nine may have been a mini-constellation of military Earth-observing satellites. Realtime Space Weather Photo Gallery
Free: Spaceweather.com Newsletter CHRISTMAS GIFTS FROM THE EDGE OF SPACE: Christmas is coming. Are you looking for a far-out 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 "BLACKCAT" at checkout for a 10% holiday discount. Far Out Gifts: Earth to Sky Store
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Realtime Comet Photo Gallery
Free: Spaceweather.com Newsletter
Realtime Aurora 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 19, 2024, the network reported 16 fireballs.
(13 sporadics, 3 December Leonis Minorids)  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, 2024 there were 2349 potentially hazardous asteroids.
| Recent & Upcoming Earth-asteroid encounters: | Asteroid | Date(UT) | Miss Distance | Velocity (km/s) | Diameter (m) | | 2024 XB16 | 2024-Dec-15 | 5.5 LD | 7.8 | 15 | | 2024 XF4 | 2024-Dec-15 | 18.3 LD | 14.5 | 63 | | 2024 XY5 | 2024-Dec-16 | 9.1 LD | 4.8 | 23 | | 2024 XB6 | 2024-Dec-16 | 17.5 LD | 6.6 | 18 | | 2024 XV6 | 2024-Dec-16 | 17.5 LD | 10.7 | 11 | | 2024 XE16 | 2024-Dec-16 | 17.7 LD | 3.7 | 47 | | 2024 VE7 | 2024-Dec-16 | 7.3 LD | 8 | 45 | | 2022 YO1 | 2024-Dec-17 | 2 LD | 14.3 | 4 | | 2024 XR6 | 2024-Dec-17 | 15.3 LD | 5.6 | 16 | | 2024 XC17 | 2024-Dec-17 | 8.1 LD | 4.8 | 12 | | 2024 XS3 | 2024-Dec-18 | 8.7 LD | 10.5 | 27 | | 2024 YA | 2024-Dec-19 | 3.7 LD | 5.3 | 16 | | 2020 XY4 | 2024-Dec-20 | 12.7 LD | 8.8 | 14 | | 2024 YD | 2024-Dec-20 | 1.2 LD | 10.5 | 12 | | 2024 XN15 | 2024-Dec-21 | 9.9 LD | 9.7 | 19 | | 2024 XQ4 | 2024-Dec-21 | 2.8 LD | 13.2 | 16 | | 2024 YC | 2024-Dec-23 | 1.6 LD | 6.4 | 12 | | 2024 XN1 | 2024-Dec-24 | 18.8 LD | 6.6 | 39 | | 2017 YD2 | 2024-Dec-27 | 18 LD | 9.9 | 6 | | 2024 AV2 | 2024-Dec-31 | 6.7 LD | 7.8 | 17 | | 2024 XP10 | 2025-Jan-02 | 19.8 LD | 8.4 | 39 | | 2021 AO4 | 2025-Jan-04 | 6.9 LD | 15.1 | 11 | | 2020 BC6 | 2025-Jan-05 | 9.6 LD | 22.2 | 248 | | 2024 BM1 | 2025-Jan-08 | 11.5 LD | 9.1 | 22 | | 2024 PT5 | 2025-Jan-09 | 4.7 LD | 1 | 12 | | 2023 OS3 | 2025-Jan-09 | 19.9 LD | 3.1 | 10 | | 2012 UK171 | 2025-Jan-11 | 10.7 LD | 6.4 | 46 | | 2023 OS | 2025-Jan-15 | 16.6 LD | 10.9 | 48 | | 2022 CE2 | 2025-Jan-16 | 11.1 LD | 13.3 | 120 | | 2022 OB5 | 2025-Jan-18 | 8.9 LD | 1.4 | 6 | | 2024 WY70 | 2025-Jan-18 | 16.5 LD | 10.2 | 261 | | 2022 BX6 | 2025-Jan-28 | 19.7 LD | 14.3 | 24 | | 2015 DJ155 | 2025-Jan-31 | 18.6 LD | 9.2 | 56 | | 2022 AV4 | 2025-Feb-03 | 16.8 LD | 3.4 | 25 | | 2018 RE3 | 2025-Feb-03 | 15.5 LD | 11.1 | 12 | | 2002 CC14 | 2025-Feb-04 | 8.4 LD | 12.7 | 39 | | 2016 CO248 | 2025-Feb-07 | 13.5 LD | 5.9 | 11 | | 2020 GZ2 | 2025-Feb-07 | 17.7 LD | 8.9 | 9 | | 2022 PK1 | 2025-Feb-07 | 15 LD | 11 | 33 | | 2012 PB20 | 2025-Feb-09 | 3.5 LD | 4.3 | 37 | | 2004 XG | 2025-Feb-16 | 15.6 LD | 9.1 | 54 | | 2024 UD26 | 2025-Feb-16 | 16.8 LD | 9.3 | 250 | 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 10 years, resulting in a unique dataset of in situ atmospheric measurements. Latest results (Nov. 2024): Atmospheric radiation is decreasing in 2024. Our latest measurements in November registered a 10-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. See also, all satellite statistics. | | | 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 |  | Got a chipped or cracked windshield that prevents you from seeing space weather events while driving? Get windshield replacement from SR Windows & Glass with free mobile auto glass service anywhere in the Phoenix area. | | 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. | |
