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Solar wind
speed: 433.9
km/sec
density: 4.2
protons/cm3
more data: ACE, SOLAR-1
Updated: Today at 0330 UT
X-ray Solar Flares
6-hr max: B9
0135 UT
Sep19
24-hr:
B9
0135 UT
Sep19
explanation
| more
data
Updated: Today at: 0330 UT
Daily Sun: 18 Sep 26
Expand: labels | no labels
Sunspot 4528 is about to rotate over the western limb of the sun. When it goes, the sun will be blank unless another sunspot emerges before it departs. Credit: NASA/SDO
Sunspot number:
0
What
is the sunspot number?
Updated 18 Sep 2026
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp=
2.33 quiet
24-hr max: Kp= 2.33 quiet
explanation | more
data
Interplanetary Mag. Field
Btotal: 5.9
nT
Bz: 5.4
nT south
more data: ACE, DSCOVR
Updated: Today at 0330 UT
Coronal Holes: 18 Sep 26
Solar wind flowing from this southern coronal holeshould reach Earth on Sept 23rd. Credit: NASA/SDO | more data
Spotless Days
Current Stretch: 0 days
2026 total: 3 days (1%)
2025 total: 0 days (0%)
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 17 Sep 2026Thermosphere Climate Index
today: 12.94x1010 W Neutral
Max: 49.4x1010 W Hot (10/1957)
Min: 2.05x1010 W Cold (02/2009)
explanation | more data: gfx, txt
Updated 16 Sep 2026
The Radio
Sun
10.7 cm flux: 107 sfu
explanation | more
data
Updated 16 Sep 2026
SPACE WEATHER
NOAA Forecasts |
|
Updated at: 2026 Sep 18 2200 UTC
FLARE |
0-24
hr |
24-48
hr |
CLASS M |
01
% |
01
% |
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: 2026 Sep 18 2200 UTC
Mid-latitudes
|
0-24
hr |
24-48
hr |
ACTIVE |
10
% |
10
% |
MINOR |
05
% |
05
% |
SEVERE |
01
% |
01
% |
High latitudes
|
0-24
hr |
24-48
hr |
ACTIVE |
15
% |
15
% |
MINOR |
20
% |
20
% |
SEVERE |
15
% |
15
% |
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This is an AI Free Zone: AI writing is everywhere -- except here. Spaceweather.com is written 100% by Dr. Tony Phillips, a carbon-based lifeform with 30 yrs of forecasting experience. If you find a mistake, rest assured it was made by a real human being.
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THE SUN IS SPOTLESS: Take a close look at today's picture of the sun. Do you see any spots? Neither do we. The sun is temporarily spotless. Emphasis on temporarily. Solar Cycle 25 is waning, but it is far from over. We expect sunspots to quickly return with more solar flares and auroras to come in the days/weeks ahead. Aurora alerts: SMS Text.
A NEW CRATER ON THE MOON: This week, researchers announced the discovery of a new crater on the Moon. NASA's Lunar Reconnaissance Orbiter found it near Mare Crisium -- a fresh gouge only two years old. Calculations suggest it was created when a 600-ton comet or asteroid hit the Moon and exploded like a Hiroshima-class bomb.
It begs the question-- how did we miss that?
The impact should have produced a flash as bright as Venus, yet no one saw it. LRO looked at the impact site on April 11, 2024--there was nothing. It looked again on May 22, 2024 and saw a 220 meter hole in the ground. Sometime between those two dates a 6.5 × 10¹⁰ kJ explosion occurred.
The answer could be as simple as sunlight. For most (64%) of the 6 weeks between the two LRO snapshots, the sun was shining over the crash site. No flash shows against such intensely sunlit ground. Also, one of the most active lunar impact observatories (ESA's NELIOTA) was off-line in 2024, so the odds of detection during the lunar night were sharply reduced.
 The IAU has named this new crater "McGetchin," after Thomas McGetchin, an Apollo-era scientist who worked on impact ballistics. Now that amateur astronomers know it exists, some are finding they themselves have photographed McGetchin Crater without realizing it. Here are two examples: #1, #2 and a finder chart.
Now is a good time to look. The Moon is a waxing gibbous in the evening sky and the crater stays lit until Sept. 27th. Don't expect to resolve the crater, but its fresh ejecta is the brightest thing for miles, so it registers as a high-contrast speck against the dark mare. Submit your images here. Realtime Space Weather Photo Gallery
Free: Space Weather Newsletter
RAINBOW DRAGONFLY EARRINGS: If you liked the Rainbow Dragonfly Pendant, you'll love the matching earrings. On July 7, 2026, the students of Earth to Sky Calculus launched them to the stratosphere onboard a cosmic ray research balloon:
You can have a pair for $149.95. Made of stained glass with a sterling silver exoskeleton, each dragonfly has a wingspan of 0.8 inches and dangles from a matching sterling silver clasp. Your order comes with a full-color greeting card showing the earrings in flight and telling the story of their journey to the stratosphere and back.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
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 September 16, 2026, the network reported 7 fireballs.
(7 sporadics)
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 19, 2026 there were 2349 potentially hazardous asteroids.
Recent
& Upcoming Earth-asteroid encounters:
Notes: LD means
"Lunar Distance." 1 LD = 384,401 km, the distance
between Earth and the Moon. 1 LD also equals 0.00256
AU.
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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. |
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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. |
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from the NOAA Space Environment Center |
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the
underlying science of space weather |
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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. |
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