Spotless Days Current Stretch: 0 days
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 11 Jul 2025
Thermosphere Climate Index
today: 18.88x1010W Warm
Max: 49.4x1010 W Hot (10/1957)
Min: 2.05x1010 W Cold (02/2009) explanation | more data:gfx, txt
Updated 10 Jul 2025
Cosmic RaysSolar Cycle 25 is intensifying, and this is reflected in the number of cosmic rays entering Earth's atmosphere. Neutron counts from the University of Oulu's Sodankyla Geophysical Observatory show that cosmic rays reaching Earth are slowly declining--a result of the yin-yang relationship between the solar cycle and cosmic rays.
Oulu Neutron Counts Percentages of the Space Age average:
today: -6.4% Very Low
48-hr change: +0.9%
Max: +11.7% Very High (12/2009)
Min: -32.1% Very Low (06/1991) explanation |more data
Updated 10 Jul 2025 @ 0700 UT
Planetary K-index
Now: Kp=
2.67 quiet
24-hr max: Kp= 2.67 quiet explanation | more
data
Interplanetary Mag. Field
Btotal: 10.90 nT
Bz: -6.12 nT south more data: ACE, DSCOVR Updated: Today at 0846 UT
Coronal Holes: 10 Jul 25
Solar wind flowing from this coronal hole could reach Earth on July 13-15. 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 10, 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 10, 2025, in Poland
"The noctilucent cloud season continues. This morning in Poland (53 N) we had another beautiful display of electric-blue clouds. I never tire of it." says photographer Marek Nikodem of Szubin, Poland.
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 10 2200 UTC
Mid-latitudes
0-24
hr
24-48
hr
ACTIVE
10
%
20
%
MINOR
01
%
05
%
SEVERE
01
%
01
%
High latitudes
0-24
hr
24-48
hr
ACTIVE
20
%
15
%
MINOR
20
%
25
%
SEVERE
10
%
30
%
Friday, Jul. 11, 2025
What's up in space
This is an AI Free Zone: AI isn't all bad. Large language models are good writers with access to vast stores of data. There's still no substitute for a human being with decades of space weather forecasting experience. This website is 100% human.
NOTHING HIT SATURN, AFTER ALL: A few days ago, we reported that something might have hit Saturn. An impact flash on July 5th appeared to signal an asteroid or comet collision. However, astronomers working with the DeTeCt project failed to confirm the flash in additional images. Nothing hit Saturn, after all.
CROSSWINDS IN THE MESOSPHERE: On July 10th, photographer Peter Rosén of Stockholm, Sweden, captured an extraordinary time-lapse video of noctilucent clouds (NLCs) rippling across the northern sky. At first glance, the scene is familiar—silvery tendrils flowing like smoke above the horizon. But take a closer look:
There are two distinct layers of clouds moving in different directions, stacked one atop the other.
"This is new to me," says Rosén, who has been watching NLCs over Sweden for the past 20 years. "There are two layers moving in opposite directions, but also interfering and creating interesting patterns."
Noctilucent clouds form when summertime plumes of water vapor rise to the mesosphere (83 km high) and frost the ashes of disintegrated meteors. The layer where these clouds form is extremely thin—typically less than 10 km from bottom to top. Yet somehow, two dynamic layers of clouds have squeezed into this narrow wafer of air.
"This is a very cool time-lapse video!" says Cora Randall, a Distinguished Professor Emerita and leading expert in NLC physics at the University of Colorado. "Using radar, Chinese researchers have recently found strong vertical wind shears in the mesosphere--a result of gravity wave activity." Rosén may have captured these exact phenomena in visual form.
Above: Maps of vertical wind shear in the noctilucent zone captured by Chinese radar (ref)
"We know that vertical wind shears can be large at NLC altitudes - so this isn't completely surprising," adds Lynn Harvey of the Laboratory for Atmospheric and Space Physics (LASP) in Boulder, CO. "But is this the first time it's been so clearly documented?"
It seems so. Rosén’s camera captured crosswinds in the mesosphere--a rare visual confirmation of complex dynamics near the edge of space.
THE ALIEN ABDUCTION CHRISTMAS ORNAMENT: "Turnabout is fair play," said the cow. You can't buy this on Amazon: The Alien Abduction Christmas Ornamant is only available from the Earth to Sky Store. On July 7, 2025, it flew to the stratosphere onboard a cosmic ray research balloon:
You can have it for $149.95. Hand-sculpted in the USA, this humorous ornament is intricately detailed, from the tied-up alien at the rear of the saucer to the cow at the helm. Durable polyresin construction makes it lightweight enough to hang on any tree, but sturdy enough to last for many Christmases to come--a guaranteed conversation starter!
The students are selling space ornaments to pay the helium bill for their cosmic ray ballooning program. Each one comes with a greeting card showing the ornament in flight and telling the story of its trip to the stratosphere and back again.
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 10, 2025, the network reported 6 fireballs.
(6 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]
Near
Earth Asteroids
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 11, 2025 there were 2349 potentially hazardous asteroids.
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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