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Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp=
1.33 quiet
24-hr max: Kp= 2.67 quiet
explanation | more
data
Interplanetary Mag. Field
Btotal: 6.92 nT
Bz: -1.66 nT south
more data: ACE, DSCOVR
Updated: Today at 1007 UT
Coronal Holes: 29 Jul 25
There are no significant coronal holes facing Earth. 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 Jul 29, 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 25, 2025, in The Netherlands
"A fine, but distant display with pronounced billow and whirl structures," says photographer Peter Paul Hattinga Verschure of Deventer, The Netherlands
See the complete NLC Photo Gallery
SPACE WEATHER
NOAA Forecasts |
|
Updated at: 2025 Jul 28 2200 UTC
FLARE |
0-24
hr |
24-48
hr |
CLASS M |
25
% |
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: 2025 Jul 28 2200 UTC
Mid-latitudes
|
0-24
hr |
24-48
hr |
ACTIVE |
15
% |
30
% |
MINOR |
05
% |
15
% |
SEVERE |
01
% |
01
% |
High latitudes
|
0-24
hr |
24-48
hr |
ACTIVE |
15
% |
15
% |
MINOR |
25
% |
30
% |
SEVERE |
25
% |
40
% |
|
|
|
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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.
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COMET 3I/ATLAS IS 7 MILES WIDE: Astronomers have been having trouble figuring out the size of interstellar Comet 3I/ATLAS. Its core is hidden by an expanding cometary atmosphere. Not anymore. Researchers using the Vera C. Rubin Observatory have found pre-discovery images of the comet, which provide a better view. The comet's core appears to be about 7 miles wide, making 3I/ATLAS the biggest interstellar object known so far. Original Research.
ASTEROID STRIKE COULD CAUSE A MOONDUST METEOR STORM: Mark your calendar. If asteroid 2024 YR4 hits the Moon on Dec. 22, 2032, Earth could experience a rare meteor storm made entirely of moondust.
Astronomers at the University of Western Ontario have analyzed what might happen if the 60-meter-wide space rock slams into the lunar surface seven years from now. In a new paper, they report that the impact would release as much energy as 6.5 megatons of TNT, blasting out a kilometer-wide crater and ejecting up to 100 million kilograms of lunar debris.
Above: The amount of debris that reaches Earth depends sensitively on where the asteroid strikes. Wiegert's team simulated impacts along the yellow-dotted corridor of possibilities.
"Up to 10% of the lunar ejecta could reach Earth within days," says planetary scientist Paul Wiegert, the leader of the study. "The resulting meteor shower could be eye-catching, with meteor rates orders of magnitude above usual background rates."
Earth's upper atmosphere would be peppered by lunar material arriving at relatively low speeds--about 11 km/s. That's much slower than typical meteors. Perseids, for instance, hit Earth at 59 km/s. As a result, the lunar meteors would appear slower, dimmer, and longer-lasting than usual. Still, they could be visible to the naked eye and quite numerous.
Their simulations suggest that the storm could go on for days:
And here's the kicker: Nearly every visible meteor in this shower would be a piece of the Moon.
The authors estimate a 4% chance of impact. That’s small, but significant. The odds will be updated in 2028, when asteroid 2024 YR4 emerges from the glare of the sun and becomes observable again. If it is on target, the asteroid could deliver the largest lunar impact in approximately 5000 years.
Read the original research here -- and stay tuned for a moondust meteor shower.
Realtime Space Weather Photo Gallery
Free: Spaceweather.com Newsletter
CHRISTMAS IN JULY: 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.
Enter coupon code "JULY" at checkout for a 10% Christmas-in-July discount.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
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 Jul 28, 2025, the network reported 15 fireballs.
(7 sporadics, 5 Southern Delta Aquariids, 2 alpha Capricornids, 1 psi Cassiopeid)
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 July 29, 2025 there were 2349 potentially hazardous asteroids.
 |
Recent
& Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT) |
Miss Distance |
Velocity (km/s) |
Diameter (m) |
| 2025 OZ |
2025-Jul-24 |
14 LD |
13.9 |
58 |
| 2025 OK1 |
2025-Jul-24 |
5.7 LD |
6.7 |
31 |
| 2025 OF2 |
2025-Jul-25 |
1.3 LD |
30.1 |
36 |
| 2025 OX |
2025-Jul-26 |
11.8 LD |
10.4 |
33 |
| 2025 OU1 |
2025-Jul-26 |
7 LD |
18.4 |
45 |
| 2025 OM4 |
2025-Jul-28 |
18.5 LD |
6.2 |
35 |
| 2018 BE5 |
2025-Jul-28 |
10.8 LD |
13.9 |
45 |
| 2025 OO4 |
2025-Jul-28 |
5.9 LD |
8.8 |
22 |
| 2025 OW |
2025-Jul-28 |
1.7 LD |
21 |
68 |
| 2025 OU2 |
2025-Jul-28 |
13.4 LD |
2.7 |
25 |
| 2025 OA4 |
2025-Jul-29 |
18.2 LD |
13.4 |
35 |
| 2025 ON1 |
2025-Jul-30 |
16.1 LD |
3.1 |
30 |
| 2025 OX3 |
2025-Jul-30 |
9.9 LD |
9.3 |
16 |
| 2025 OL1 |
2025-Jul-30 |
5.4 LD |
7.6 |
34 |
| 2025 OU4 |
2025-Jul-30 |
1.8 LD |
12.5 |
15 |
| 2025 OD1 |
2025-Jul-31 |
9.8 LD |
12.3 |
35 |
| 2025 OR |
2025-Jul-31 |
12.8 LD |
8 |
30 |
| 2025 OC5 |
2025-Jul-31 |
12.6 LD |
3.4 |
9 |
| 2025 OW3 |
2025-Aug-03 |
7.7 LD |
13.9 |
20 |
| 2025 OA3 |
2025-Aug-04 |
6 LD |
13.6 |
35 |
| 2025 OT4 |
2025-Aug-07 |
3.9 LD |
6 |
40 |
| 2025 OJ1 |
2025-Aug-08 |
13.5 LD |
14.2 |
92 |
| 2019 CO1 |
2025-Aug-08 |
17.8 LD |
10.5 |
65 |
| 2022 QB1 |
2025-Aug-10 |
8.9 LD |
3.9 |
6 |
| 2025 OR4 |
2025-Aug-12 |
3.5 LD |
4.6 |
17 |
| 2021 PJ1 |
2025-Aug-15 |
4.4 LD |
9.3 |
24 |
| 2025 CO3 |
2025-Aug-16 |
19.8 LD |
8.4 |
90 |
| 1997 QK1 |
2025-Aug-20 |
7.9 LD |
9.8 |
315 |
| 2025 OV4 |
2025-Aug-20 |
7.6 LD |
10.7 |
52 |
| 2025 OB3 |
2025-Aug-21 |
8.8 LD |
7 |
48 |
| 2022 QD3 |
2025-Aug-21 |
15 LD |
6.9 |
35 |
| 2023 PX |
2025-Aug-22 |
2.4 LD |
8.3 |
23 |
| 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 |
33 |
| 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 |
164 |
| 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 |
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.
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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 |
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