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SPACE WEATHER
NOAA Forecasts |
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Updated at: 2026 May 20 2200 UTC
FLARE |
0-24
hr |
24-48
hr |
CLASS M |
20
% |
25
% |
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: 2026 May 20 2200 UTC
Mid-latitudes
|
0-24
hr |
24-48
hr |
ACTIVE |
20
% |
30
% |
MINOR |
05
% |
05
% |
SEVERE |
01
% |
01
% |
High latitudes
|
0-24
hr |
24-48
hr |
ACTIVE |
20
% |
20
% |
MINOR |
35
% |
35
% |
SEVERE |
25
% |
30
% |
|
|
|
 |
|
|
|
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|
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This is an AI Free Zone: AI is everywhere -- except here. Spaceweather.com is written 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 FARSIDE DANGER IS SUBSIDING: New data from Europe's Solar Orbiter show that a massive farside sunspot group first detected last week is now dispersing. The sunspot has not produced an X-flare in five days, and even M-class flares are becoming scarce. This sunspot may pose no danger to Earth when it turns toward us this weekend. Free: Space Weather Newsletter.
\A VERY RARE ICE HALO: Experts call it a "suncave Parry arc." Usually, you have to go to the Arctic to find one. Last week, however, Marcella Giulia Pace saw the rarity in Sicily.
"On May 15th, I was in my garden, surrounded by the quietness of the Sicilian countryside, when, lifting my eyes to the sky, I saw an extraordinary halo display," says Pace. "With my camera in hand, I began running along the country road beside my home, searching for an open field that could reveal the entire composition."
The luminous network included a circumzenithal arc, a supralateral arc, a suncave Parry arc, an upper tangent arc, a 22° halo, a parhelic circle and a sundog.
"As I ran, the complex display kept transforming before my eyes," says Pace. "The greatest surprise came when I saw a Parry arc forming above the upper tangent arc--the rarest phenomenon of all!"
Suncave Parry arcs are exceptionally rare because
they require sunlight to pass through column-shaped ice crystals suspended in a very specific, improbable, and unstable alignment in the atmosphere. They were first recorded in 1820 by William Edward Parry while icebound off Melville Island in the Canadian Arctic.
"The entire spectacle lasted only twenty minutes," she says. "Then thicker clouds slowly advanced, covering the sun and dissolving one by one all the arcs that had transformed my sky into a mosaic of light and ice."
Realtime Space Weather Photo Gallery
Free: Spaceweather.com Newsletter
ALWAYS AND FOREVER RUBY SPACE PENDANT: Are you looking for a far out gift? Consider the Always and Forever Ruby Space Pendent. The students of Earth to Sky Calculus launched it to the stratosphere onboard a cosmic ray research balloon:
You can have it for $219.95. Engraved with the words "I love you always and forever", this sterling silver pendant has a heart-shaped ruby crystal in the middle surrouunded by a ring of glittering 5A cubic zirconia nuggets. It is a visually striking necklace perfect for anniversaries and romantic birthdays.
The students are selling space pendants to pay the helium bill for their cosmic ray ballooning program. Each one comes with a greeting card showing the jewelry in flight and telling the story of its trip to the stratosphere and back again.
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 May 20, 2026, the network reported 10 fireballs.
(9 sporadics, 1 eta 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 May 21, 2026 there were 2349 potentially hazardous asteroids.
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Recent
& Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT) |
Miss Distance |
Velocity (km/s) |
Diameter (m) |
| 2026 JH1 |
2026-May-15 |
15.5 LD |
13.4 |
31 |
| 2026 JQ3 |
2026-May-15 |
2.2 LD |
7.8 |
13 |
| 2026 JN4 |
2026-May-15 |
0 LD |
23.2 |
1 |
| 2026 JK2 |
2026-May-15 |
1.2 LD |
20.5 |
26 |
| 2026 JO4 |
2026-May-15 |
11.6 LD |
15.5 |
21 |
| 2026 KG |
2026-May-15 |
2.8 LD |
7.1 |
6 |
| 2026 JU |
2026-May-16 |
5.2 LD |
8.4 |
23 |
| 2026 JF4 |
2026-May-16 |
4.1 LD |
9.8 |
8 |
| 2023 VR5 |
2026-May-16 |
7.5 LD |
2.3 |
10 |
| 2026 KD |
2026-May-17 |
0.3 LD |
12.2 |
6 |
| 2026 JY2 |
2026-May-17 |
8.3 LD |
13.8 |
19 |
| 2026 JB4 |
2026-May-17 |
9.5 LD |
6.7 |
14 |
| 2026 KA |
2026-May-17 |
1.3 LD |
15.6 |
19 |
| 2026 KT |
2026-May-17 |
0.5 LD |
5.2 |
2 |
| 2026 HC5 |
2026-May-17 |
7.1 LD |
6.7 |
22 |
| 2026 KU |
2026-May-17 |
11.4 LD |
14.5 |
24 |
| 2025 KR4 |
2026-May-18 |
15.2 LD |
5.9 |
22 |
| 2026 JP3 |
2026-May-18 |
17.7 LD |
16.5 |
39 |
| 2026 KR |
2026-May-18 |
5.4 LD |
6.3 |
10 |
| 2026 KQ |
2026-May-18 |
0.5 LD |
6 |
3 |
| 2026 KB |
2026-May-18 |
0.6 LD |
9.6 |
12 |
| 2026 JH2 |
2026-May-18 |
0.2 LD |
9.1 |
19 |
| 2026 KC |
2026-May-19 |
3.5 LD |
8.4 |
13 |
| 2026 JP1 |
2026-May-20 |
17.7 LD |
15.4 |
57 |
| 2026 KP |
2026-May-20 |
2.2 LD |
16.1 |
14 |
| 2026 JD3 |
2026-May-21 |
6.9 LD |
7.7 |
12 |
| 2026 JD4 |
2026-May-21 |
4.3 LD |
24.1 |
36 |
| 2026 JG1 |
2026-May-21 |
13.4 LD |
14.6 |
34 |
| 2026 JA4 |
2026-May-21 |
7.6 LD |
7.8 |
13 |
| 2026 KF |
2026-May-22 |
1.7 LD |
14.1 |
21 |
| 2026 JE1 |
2026-May-22 |
2.9 LD |
4.7 |
12 |
| 2026 JC4 |
2026-May-22 |
15 LD |
21.3 |
46 |
| 2026 KK |
2026-May-23 |
15.3 LD |
8.4 |
25 |
| 2026 JM |
2026-May-23 |
5.2 LD |
7.8 |
23 |
| 2023 KH4 |
2026-May-24 |
5.5 LD |
7.9 |
14 |
| 2023 KZ1 |
2026-May-24 |
9 LD |
13.4 |
20 |
| 2026 JW3 |
2026-May-25 |
13.2 LD |
14.8 |
63 |
| 2026 JJ |
2026-May-27 |
18.8 LD |
4.8 |
24 |
| 2026 HW2 |
2026-May-29 |
17.7 LD |
12.5 |
121 |
| 2023 BM4 |
2026-May-30 |
12.2 LD |
5.7 |
64 |
| 2026 JN |
2026-Jun-01 |
16 LD |
7.8 |
50 |
| 2021 KN2 |
2026-Jun-03 |
8.9 LD |
8.9 |
7 |
| 2018 GE |
2026-Jun-07 |
16.4 LD |
3.1 |
11 |
| 2016 VS |
2026-Jun-12 |
20 LD |
11.1 |
12 |
| 530520 |
2026-Jun-12 |
16.1 LD |
14.6 |
152 |
| 2003 LN6 |
2026-Jun-18 |
3.7 LD |
3.9 |
41 |
| 2025 WC4 |
2026-Jun-21 |
10.2 LD |
19.2 |
304 |
| 2015 LM24 |
2026-Jun-22 |
18.2 LD |
13.8 |
71 |
| 152637 |
2026-Jun-27 |
6.7 LD |
8.9 |
947 |
| 523808 |
2026-Jul-04 |
9.1 LD |
16.8 |
479 |
| 2023 YO1 |
2026-Jul-05 |
6.5 LD |
2.7 |
23 |
| 2007 AA2 |
2026-Jul-11 |
17.8 LD |
7.2 |
43 |
| 2025 PN7 |
2026-Jul-17 |
11.6 LD |
2.6 |
19 |
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 |
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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 |
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from
the NOAA Space Environment Center |
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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 |
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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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