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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= 3.67 quiet
explanation | more
data
Interplanetary Mag. Field
Btotal: 4.85 nT
Bz: 0.02 nT north
more data: ACE, DSCOVR
Updated: Today at 1152 UT
Coronal Holes: 24 Sep 25
Earth is inside a stream of solar wind flowing from this departing coronal hole. 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 Sep 24, 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. The seson is ending in an interesting way. Usually the clouds vanish in August, but they have persisted and sometimes been quite storng as August comes to an end.
Above: Aug. 21, 2025, Björköby, Finland
"These late season noctilucent clouds drifted in front of the crescent moon. It was quite beautiful," says photographer Sebastian Sainio.
See the complete NLC Photo Gallery
SPACE WEATHER
NOAA Forecasts |
|
Updated at: 2025 Sep 23 2200 UTC
FLARE |
0-24
hr |
24-48
hr |
CLASS M |
35
% |
35
% |
CLASS X |
01
% |
01
% |
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 Sep 23 2200 UTC
Mid-latitudes
|
0-24
hr |
24-48
hr |
ACTIVE |
20
% |
10
% |
MINOR |
05
% |
01
% |
SEVERE |
01
% |
01
% |
High latitudes
|
0-24
hr |
24-48
hr |
ACTIVE |
15
% |
15
% |
MINOR |
25
% |
20
% |
SEVERE |
30
% |
20
% |
|
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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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A CME IS HEADING FOR INTERSTELLAR COMET ATLAS: How often does a CME from our sun strike a comet from interstellar space? Almost never--so today’s collision is worth watching. According to a NASA forecast model, a CME launched on Sept. 19th will reach Comet 3I/ATLAS on Sept. 24th or 25th. CMEs hitting Solar System comets have been known to kink or even disconnect their tails. What happens to an interstellar comet is anyone’s guess.
The timing is fortuitous. The potential impact comes only a week before the comet disappears into the sun’s glare, giving astronomers a narrow window to record the event. It also coincides with the comet’s recent brightening--a 40-fold increase since the beginning of September.
Gerald Rhemann and Michael Jäger took this picture of the comet on Sept. 17th. "We can confirm Thomas Lehmann’s recent detection of the comet’s increase in brightness," says Jäger. Since September began, it has jumped in magnitude from +16 to +12.
Most of the brightness increase is in one color: green. This suggests a surge of gas production as the comet nears the sun. The key compound is diatomic carbon (C2), which glows emerald when energized by solar UV radiation.
This plot from Marshall Eubanks of Space Initiatives, Inc. shows what is probably happening:
His model breaks the comet's brightness into two pieces--a contribution from dust (red line) and a contribution from gas (blue dashed line). The surging gas component is making the comet bright just in time for its early-October encounter with Mars and a fleet of spacecraft orbiting the Red Planet. We will cover *that* later this week. Stay tuned!
Thanks! To Marshall Eubanks for noticing and pointing out the CME-comet encounter.
Realtime Comet ATLAS Photo Gallery
Free: Spaceweather.com Newsletter
ALIEN RANSOM CHRISTMAS ORNAMENT: You can't buy this on Amazon. The Alien Ransom Christmas Ornament is only available from the Earth to Sky Store. On Sept. 15, 2025, it flew to the stratosphere onboard a cosmic ray research balloon:
You can have it for $129.95. Think of it as Santa's ransom :) Hand-sculpted in the USA, this humorous ornament is intricately detailed, from the alien pilot to Santa's boots. Durable polyresin construction makes it lightweight enough to hang on any tree but sturdy enough to last for many Christmases to come.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
Realtime Space Weather 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 Sep 23, 2025, the network reported 16 fireballs.
(15 sporadics, 1 Southern Taurid)
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 September 24, 2025 there were 2349 potentially hazardous asteroids.
 |
Recent
& Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT) |
Miss Distance |
Velocity (km/s) |
Diameter (m) |
| 2025 RT3 |
2025-Sep-18 |
2.7 LD |
15.1 |
13 |
| 2025 SC |
2025-Sep-18 |
1.2 LD |
3.2 |
3 |
| 2025 FA22 |
2025-Sep-18 |
2.2 LD |
10.8 |
166 |
| 2025 RC2 |
2025-Sep-18 |
4.2 LD |
18.6 |
19 |
| 2025 SZ2 |
2025-Sep-18 |
13.3 LD |
12.3 |
27 |
| 2025 RP2 |
2025-Sep-19 |
11.3 LD |
7.7 |
29 |
| 2025 SZ1 |
2025-Sep-19 |
3.3 LD |
11.2 |
18 |
| 2025 SX2 |
2025-Sep-19 |
3.7 LD |
6.4 |
22 |
| 2025 RL2 |
2025-Sep-19 |
0.6 LD |
9.7 |
22 |
| 2025 SY1 |
2025-Sep-19 |
0.1 LD |
7.9 |
2 |
| 2025 RW3 |
2025-Sep-19 |
4.2 LD |
15.1 |
12 |
| 2025 SL2 |
2025-Sep-19 |
18.4 LD |
14.4 |
27 |
| 2025 RD4 |
2025-Sep-20 |
6.4 LD |
19.3 |
19 |
| 2025 SH2 |
2025-Sep-20 |
11 LD |
14.2 |
20 |
| 2025 ST1 |
2025-Sep-21 |
4.9 LD |
8 |
12 |
| 2025 SO1 |
2025-Sep-21 |
9.7 LD |
11.4 |
29 |
| 2025 SN4 |
2025-Sep-21 |
1.9 LD |
10.7 |
29 |
| 2025 RE6 |
2025-Sep-21 |
5.4 LD |
13.4 |
8 |
| 2025 PJ1 |
2025-Sep-21 |
11.6 LD |
11.8 |
131 |
| 2025 SK3 |
2025-Sep-22 |
6.7 LD |
8.6 |
13 |
| 2025 SF4 |
2025-Sep-22 |
16.4 LD |
8.2 |
42 |
| 2025 SG4 |
2025-Sep-22 |
18.4 LD |
10.3 |
41 |
| 2025 RO3 |
2025-Sep-22 |
9.1 LD |
16.8 |
34 |
| 2022 SW12 |
2025-Sep-23 |
15 LD |
17.6 |
211 |
| 2025 SP3 |
2025-Sep-23 |
1.1 LD |
12.3 |
7 |
| 2018 QT1 |
2025-Sep-23 |
13.1 LD |
12.7 |
134 |
| 2025 SR3 |
2025-Sep-23 |
16.8 LD |
24.2 |
68 |
| 2021 RN16 |
2025-Sep-23 |
10.1 LD |
8.8 |
7 |
| 2025 SM2 |
2025-Sep-23 |
6.6 LD |
13.2 |
17 |
| 2025 SX |
2025-Sep-24 |
14.9 LD |
5 |
16 |
| 2025 RX3 |
2025-Sep-25 |
15.1 LD |
11.2 |
17 |
| 2025 RX4 |
2025-Sep-25 |
2.8 LD |
10 |
40 |
| 2025 SB4 |
2025-Sep-25 |
3.7 LD |
17.6 |
23 |
| 2025 SW |
2025-Sep-25 |
4.2 LD |
8.1 |
99 |
| 2025 SS |
2025-Sep-25 |
5 LD |
8.9 |
29 |
| 2025 RC4 |
2025-Sep-25 |
8.5 LD |
10 |
20 |
| 2025 RE5 |
2025-Sep-26 |
17.7 LD |
7.9 |
26 |
| 2025 SU3 |
2025-Sep-26 |
18.3 LD |
9.9 |
39 |
| 2025 SD4 |
2025-Sep-26 |
4.6 LD |
19.3 |
24 |
| 2025 SA1 |
2025-Sep-28 |
5 LD |
8.7 |
21 |
| 2019 SF6 |
2025-Sep-28 |
20 LD |
8.4 |
20 |
| 2025 SC4 |
2025-Sep-29 |
19.3 LD |
5.5 |
23 |
| 2025 RH4 |
2025-Sep-29 |
17.9 LD |
17.3 |
52 |
| 152664 |
2025-Sep-29 |
10.1 LD |
18.6 |
412 |
| 2023 EH2 |
2025-Sep-30 |
19.8 LD |
17.8 |
51 |
| 2025 SA3 |
2025-Sep-30 |
7 LD |
7.2 |
17 |
| 2025 SZ |
2025-Oct-01 |
9 LD |
2 |
8 |
| 2025 QL23 |
2025-Oct-01 |
7.1 LD |
10 |
75 |
| 2025 SY |
2025-Oct-02 |
12.2 LD |
5.9 |
15 |
| 2025 SH |
2025-Oct-02 |
3.6 LD |
3.7 |
12 |
| 2020 GE1 |
2025-Oct-02 |
13.7 LD |
4.7 |
14 |
| 2025 RH2 |
2025-Oct-03 |
19.6 LD |
5.1 |
37 |
| 2018 SP1 |
2025-Oct-05 |
13.2 LD |
16.4 |
85 |
| 2022 TU1 |
2025-Oct-08 |
16.9 LD |
12.9 |
10 |
| 2020 QU5 |
2025-Oct-09 |
7.1 LD |
13.6 |
26 |
| 2022 AY5 |
2025-Oct-14 |
7.4 LD |
8.4 |
5 |
| 2022 UY3 |
2025-Oct-15 |
10.2 LD |
7.4 |
15 |
| 2022 UU15 |
2025-Oct-19 |
14.8 LD |
16.1 |
34 |
| 2023 UK3 |
2025-Oct-21 |
6.7 LD |
9 |
5 |
| 2024 GD2 |
2025-Oct-22 |
17.8 LD |
4.2 |
28 |
| 2022 HM1 |
2025-Oct-23 |
15.1 LD |
13.3 |
27 |
| 2012 TP231 |
2025-Oct-25 |
15.2 LD |
6.7 |
37 |
| 2020 FA5 |
2025-Oct-26 |
15.7 LD |
26.5 |
210 |
| 2009 HC |
2025-Oct-26 |
8.6 LD |
4.2 |
39 |
| 434196 |
2025-Oct-27 |
17.4 LD |
10.9 |
171 |
| 2023 VK6 |
2025-Nov-03 |
7.6 LD |
9.6 |
15 |
| 2021 VQ10 |
2025-Nov-08 |
9 LD |
15 |
13 |
| 2019 UH7 |
2025-Nov-08 |
13.3 LD |
5.8 |
11 |
| 2018 KC |
2025-Nov-09 |
16 LD |
9.3 |
11 |
| 2017 WG14 |
2025-Nov-09 |
16.7 LD |
11.7 |
45 |
| 2020 VK4 |
2025-Nov-10 |
16.4 LD |
3.8 |
9 |
| 2012 VC26 |
2025-Nov-11 |
13.3 LD |
6.4 |
6 |
| 2019 VL5 |
2025-Nov-14 |
14.7 LD |
9.1 |
24 |
| 2022 FG4 |
2025-Nov-17 |
18.7 LD |
22.2 |
105 |
| 3361 |
2025-Nov-19 |
14.8 LD |
9.1 |
435 |
| 2013 NJ4 |
2025-Nov-20 |
12.6 LD |
6.4 |
12 |
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 |
 |
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