 | | | Switch to: Europe, USA, New Zealand, Antarctica Credit: NOAA/Ovation  Planetary K-index
Now: Kp= 2.00 quiet
24-hr max: Kp= 2.67 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 6.54 nT
Bz: -0.07 nT south
more data: ACE, DSCOVR
Updated: Today at 1147 UT Coronal Holes: 04 Aug 25 
Solar wind flowing from this southern coronal hole could reach Earth on Aug. 9-10. Credit: NASA/SDO | 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 Aug 03, 2025, the Arctic stratosphere is much too hot for polar stratospheric clouds. | more data. Noctilucent Clouds
The northern season for noctilucent clouds is underway. First reports of the electric-blue clouds came from Russia on May 28, 2025. Since then, the clouds have spread to lower latitudes, reaching Paris, France, during a major outbreak on June 23, 2025.
Above: July 30, 2025, approx. 37000 feet above Hudson Bay, Canada
"While flying the Dreamliner from Calgary to Rome Italy on July 30th, the sun was starting to set as we flew north towards the Hudson Bay at 37,000 feet. The sky lit up in two different directions! In front of us, to the East, we could see the aurora light up the sky. And to the North we saw a nice dazzling display of noctilucent clouds. Being an airline pilot definitely offers the best office view!" says photographer Matt Melnyk
See the complete NLC Photo Gallery
SPACE WEATHER
NOAA Forecasts | | Updated at: 2025 Aug 04 2200 UTC FLARE | 0-24 hr | 24-48 hr | CLASS M | 40 % | 40 % | 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: 2025 Aug 04 2200 UTC Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 35 % | 20 % | MINOR | 15 % | 05 % | SEVERE | 01 % | 01 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 15 % | 15 % | MINOR | 30 % | 30 % | SEVERE | 45 % | 25 % | | | |  | | | | | | | | | | | This is an AI Free Zone: Text created by Large Language Models is spreading 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. | | | INCREASING CHANCE OF FLARES: Don't be surprised if there's a strong solar flare today. Over the weekend, two sunspots developed unstable 'delta-class' magnetic fields: 4167 and 4168. Both harbor energy for X-flares and significant CMEs. Solar flare alerts: SMS Text MORNING SKY SHOW: Set your alarm for dawn. The two brightest planets in the solar system are converging for a close encounter in the morning twilight sky. "Clear weather in the eastern United States gave us an opportunity to see the narrowing gap between Venus and Jupiter," says Eric G. David, who took this picture on Aug. 3rd from Fredericksburg, Virginia: 
His full-sized photo shows the planets in context of six constellations. Venus has just joined Jupiter inside the perimeter of Gemini, where the two planets will remain for the rest of August. The alignment is about to get much tighter and considerably more beautiful. Every morning this week, Jupiter and Venus will draw closer together until on Aug. 11-13, they will be less than 1 degree apart. Wake up early and enjoy the show! Sky maps: Aug. 5, 6, 7, 8, 9, 10, 11, 12, 13. Realtime Space Weather Photo Gallery
Free: Spaceweather.com Newsletter NASA SPACEWALKER $1 COINS: The US Mint has just released a new set of limited edition $1 coins to honor NASA's astronaut core. Yesterday, the students of Earth to Sky Calculus launched them to the edge of space onboard a cosmic ray research balloon. Here they are, parachuting back from the stratosphere: 
You can have a single coin for $49.95 or an entire unbroken roll for $299.95. No longer available from the US Mint, these rare coins flew 113,949 feet above the Sierra Nevada on July 31, 2025. One side shows an American astronaut conducting a spacewalk outside the International Space Station; the other side features the Statue of Liberty in profile. Bonus: If you need to, you can spend these coins. They're real legal tender. The students are selling space coins to support to support their cosmic ray research program. (Helium is expensive!) Each order comes with a greeting card showing the coins in flight and telling the story of their journey to the stratosphere and back again. Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
Realtime Comet ATLAS Photo Gallery
Free: Spaceweather.com Newsletter
Realtime Aurora Photo Gallery
Free: Spaceweather.com Newsletter
Realtime Noctilucent Cloud 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 Aug 04, 2025, the network reported 12 fireballs.
(5 sporadics, 5 Perseids, 2 Southern Delta Aquariids)  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 August 4, 2025 there were 2349 potentially hazardous asteroids.
 | Recent & Upcoming Earth-asteroid encounters: | Asteroid | Date(UT) | Miss Distance | Velocity (km/s) | Diameter (m) | | 2025 ON1 | 2025-Jul-30 | 16.1 LD | 3.1 | 30 | | 2025 PD | 2025-Jul-30 | 1.5 LD | 9.9 | 11 | | 2025 OX3 | 2025-Jul-30 | 9.9 LD | 9.3 | 16 | | 2025 OL1 | 2025-Jul-30 | 5.4 LD | 7.6 | 35 | | 2025 OM10 | 2025-Jul-30 | 5.8 LD | 5.7 | 43 | | 2025 OU4 | 2025-Jul-30 | 1.8 LD | 12.5 | 16 | | 2025 PN | 2025-Jul-30 | 1.7 LD | 19.4 | 24 | | 2025 PE | 2025-Jul-31 | 2.1 LD | 15.5 | 57 | | 2025 OD1 | 2025-Jul-31 | 9.8 LD | 12.3 | 35 | | 2025 PC | 2025-Jul-31 | 0.3 LD | 9.5 | 5 | | 2025 OR | 2025-Jul-31 | 12.8 LD | 8 | 35 | | 2025 OC5 | 2025-Jul-31 | 12.6 LD | 3.4 | 9 | | 2025 OY8 | 2025-Jul-31 | 1.8 LD | 10.7 | 11 | | 2025 OY10 | 2025-Aug-01 | 2.4 LD | 7.8 | 9 | | 2025 PU | 2025-Aug-02 | 0.1 LD | 10.5 | 3 | | 2025 OU12 | 2025-Aug-03 | 5.9 LD | 4.4 | 7 | | 2025 OC6 | 2025-Aug-03 | 6.3 LD | 4.1 | 8 | | 2025 OW3 | 2025-Aug-03 | 7.7 LD | 13.9 | 21 | | 2025 OA3 | 2025-Aug-04 | 6 LD | 13.6 | 37 | | 2025 PA | 2025-Aug-04 | 8.6 LD | 9.9 | 37 | | 2025 OT7 | 2025-Aug-05 | 11.4 LD | 21.6 | 53 | | 2025 OW9 | 2025-Aug-06 | 14.8 LD | 6.9 | 13 | | 2025 OQ5 | 2025-Aug-07 | 4.2 LD | 16.7 | 49 | | 2025 OT4 | 2025-Aug-07 | 3.9 LD | 6 | 41 | | 2025 OJ1 | 2025-Aug-08 | 13.5 LD | 14.2 | 97 | | 2019 CO1 | 2025-Aug-08 | 17.8 LD | 10.5 | 65 | | 2025 OX7 | 2025-Aug-09 | 20 LD | 4 | 15 | | 2025 OY12 | 2025-Aug-09 | 4.1 LD | 12.3 | 32 | | 2022 QB1 | 2025-Aug-10 | 8.9 LD | 3.9 | 6 | | 2025 OR4 | 2025-Aug-12 | 3.5 LD | 4.6 | 18 | | 2025 OJ10 | 2025-Aug-13 | 9.2 LD | 6.4 | 28 | | 2025 OL10 | 2025-Aug-13 | 10.4 LD | 7.2 | 11 | | 2021 PJ1 | 2025-Aug-15 | 4.4 LD | 9.3 | 24 | | 2025 CO3 | 2025-Aug-16 | 19.8 LD | 8.4 | 90 | | 2025 PM | 2025-Aug-17 | 2.7 LD | 13.5 | 50 | | 2025 OV4 | 2025-Aug-20 | 7.6 LD | 10.8 | 52 | | 1997 QK1 | 2025-Aug-20 | 7.9 LD | 9.8 | 315 | | 2025 OB3 | 2025-Aug-21 | 8.8 LD | 7 | 50 | | 2022 QD3 | 2025-Aug-21 | 15 LD | 6.9 | 35 | | 2023 PX | 2025-Aug-22 | 2.4 LD | 8.3 | 23 | | 2025 PR | 2025-Aug-23 | 17.6 LD | 3.4 | 24 | | 2019 QQ6 | 2025-Aug-24 | 9.4 LD | 17.2 | 31 | | 2017 RK15 | 2025-Aug-29 | 15.8 LD | 13.2 | 26 | | 2020 TS1 | 2025-Aug-29 | 17.8 LD | 3.3 | 5 | | 1998 SH2 | 2025-Aug-30 | 8.1 LD | 17.3 | 246 | | 2025 OG1 | 2025-Sep-05 | 14.5 LD | 4.2 | 35 | | 2019 JG1 | 2025-Sep-09 | 18.8 LD | 7.9 | 17 | | 2009 FF | 2025-Sep-11 | 6.8 LD | 12.9 | 155 | | 2015 SA | 2025-Sep-13 | 10.3 LD | 9.1 | 31 | | 2022 SS2 | 2025-Sep-13 | 2.4 LD | 7.2 | 13 | | 2025 FA22 | 2025-Sep-18 | 2.2 LD | 10.8 | 166 | | 2022 SW12 | 2025-Sep-23 | 15 LD | 17.6 | 210 | | 2021 RN16 | 2025-Sep-23 | 10.1 LD | 8.8 | 7 | | 2018 QT1 | 2025-Sep-23 | 13 LD | 12.7 | 138 | | 2019 SF6 | 2025-Sep-28 | 20 LD | 8.4 | 20 | | 152664 | 2025-Sep-29 | 10.1 LD | 18.6 | 412 | | 2020 GE1 | 2025-Oct-02 | 13.7 LD | 4.7 | 14 | 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 sharply 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. | |
