 | | | Switch to: Europe, USA, New Zealand, Antarctica Credit: NOAA/Ovation  Planetary K-index
Now: Kp= 0.67 quiet
24-hr max: Kp= 1.33 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 4.43 nT
Bz: -2.83 nT south
more data: ACE, DSCOVR
Updated: Today at 1147 UT Coronal Holes: 25 Apr 24 
There are no significant equatorial coronal holes on the Earthside of the sun. Credit: SDO/AIA  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 Apr. 24, 2024, the Arctic stratosphere is much too warm for Type II polar stratospheric clouds. | more data. Noctilucent Clouds
The southern season for NLCs is over. The first clouds were detected inside the Antarctic Circle on Dec. 4, 2023, by the NOAA 21 satellite. The same satellite detected the last cloud on Feb. 21, 2024. Daily maps are now blank:
Updated: Feb 22, 2024
An instrument onboard NOAA 21 (OMPS LP) is able to detect NLCs (also known as "polar mesospheric clouds" or PMCs). Now that the southern season has ended, attention turns to the northern hemisphere. The first NLCs should appear inside the Arctic Circle in mid to late May.
SPACE WEATHER
NOAA Forecasts | | Updated at: 2024 Apr 24 2200 UTC FLARE | 0-24 hr | 24-48 hr | CLASS M | 75 % | 75 % | CLASS X | 15 % | 15 % | Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm Updated at: 2024 Apr 24 2200 UTC Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 35 % | 35 % | MINOR | 25 % | 20 % | SEVERE | 05 % | 05 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 10 % | 10 % | MINOR | 25 % | 30 % | SEVERE | 60 % | 55 % | | | |  | | | | | | | | | | | This is an AI Free Zone! Text created by Large Language Models is spreading rapidly across the Internet. It's well-written, artificial, frequently inaccurate. If you find a mistake on Spaceweather.com, rest assured it was made by a real human being. | | | GEOMAGNETIC STORM WATCH (G1): One or more CMEs could graze Earth on April 25-26, sparking a minor G1-class geomagnetic storm. The CMEs were hurled into space earlier this week by explosive activity in sunspot super-group AR3638-50. CME impact alerts: SMS Text GLOBAL AURORAS ON MARS: Earth isn't the only planet with auroras. Mars has them, too--on a global scale.
"Mars is experiencing its greatest level of auroral activity in the past 10 years," says Nick Schneider of the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP). "In February alone, there were three episodes of global auroras--an 'aurora hat trick' we've never seen before."
Orbiting high above Mars, NASA's MAVEN spacecraft recorded the auroras on 3-4 Feb, 7-10 Feb and 15-16 Feb. This animation shows the last two of these episodes in a looping time series: Spaceweather.com actually predicted some of these events, prompted by SOHO coronagraph observations of CMEs heading toward Mars. "Your predictions came true!" says Schneider.
Schneider leads the team for MAVEN's Imaging Ultraviolet Spectrograph (IUVS), the instrument that detected the auroras. All the purple pixels in the animation are a false color representation of the aurora's ultraviolet glow. Martian auroras probably have a visible light component, too, but MAVEN's cameras are not able to see them.
Here on Earth we would love it if auroras were global. Seeing Northern Lights with equal ease from the equator and the poles would check off a lot of bucket lists. Be careful what you wish for, though. Martian auroras can be global because the Red Planet has almost no protection from solar storms. It lacks an Earth-like magnetic field, so particles from the sun penetrate its atmosphere with ease--everywhere.
The dramatic auroras of February 2024 were caused by "SEPs"--solar energetic particles. SEPs are accelerated by shock waves within approaching CMEs. When they strike Mars's atmosphere, they cause it to glow. 
"Mars is currently getting hit by roughly 1 to 2 CMEs every month, bringing a hefty supply of SEPs," says Rebecca Jolitz, a member of the MAVEN Solar Energetic Particle (SEP) instrument team at UC Berkeley's Space Sciences Lab. "However, a CME doesn't actually have to hit to be effective. SEPs coming in sideways from 'remote CMEs' can light up the skies as well."
Schneider and Jolitz are looking forward to the months ahead. "Solar Cycle 25 is far from over, and we expect many more CME strikes," Schneider says. "This will give us a chance to study how solar storms affect the atmosphere of Mars--a key goal of the MAVEN mission. It's the kind of fun we've been waiting for!" Extra: Schneider notes that SEPs aren't the only way to make auroras on Mars. Protons in the solar wind and magnetic reconnection can do the trick, too, producing their own forms and colors. Stay tuned for more stories about the rich variety of Martian auroras as Solar Cycle 25 unfolds.
Realtime Aurora Photo Gallery
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TAHITIAN BLACK SOLAR ECLIPSE PEARL: It came from Tahiti, and now it has touched the shadow of the Moon. On April 8, 2024, the students of Earth to Sky Calculus launched this black pearl into a total eclipse of the sun over Texas. Riding on a cosmic ray research balloon, the pearl was 86,564 feet high when lunar darkness swallowed it for 3 minutes 45 seconds: 
You can have it for $299.95. Measuring 9 mm in diameter, this genuine Tahitian pearl has an 18K rose gold clasp and is suspended from a matching 925 Sterling Silver chain. It comes with a greeting card showing the pearl in flight and telling the story of its journey to the edge of space during the 2024 total eclipse.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education A SUNSPOT SUPER-GROUP: A remarkable "super group" has formed in the sun's southern hemisphere. Just south of the equator, five sunspots are crowded together in close proximity with shifting areas of magnetic connection. The behemoth is crackling with solar flares: 
Amateur astronomer Andy Devey sends this movie from Mojacar, Spain: "I filmed the complex area consisting of five separate active regions between 10:00 and 12:35 UT on April 24th," he says. "Several C-class and almost M-class flares can be seen." The five sunspots are AR3638, AR3643, AR3645, AR3647 and AR3650. Bumping together, they have jointly produced three to five M-flares per day all week long. This activity is expected to continue as the super-group rounds the western limb of the sun where, for a day or so, it will be magnetically connected to Earth via the Parker Spiral. Debris (especially energetic protons) guided by the spiral to Earth could cause radiation storms on April 26-28. Stay tuned! Solar flare alerts: SMS Text Realtime Space Weather Photo Gallery
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Realtime Comet Photo Gallery
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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 Apr 24, 2024, the network reported 9 fireballs.
(6 sporadics, 3 Lyrids)  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 April 25, 2024 there were 2349 potentially hazardous asteroids.
 | Recent & Upcoming Earth-asteroid encounters: | Asteroid | Date(UT) | Miss Distance | Velocity (km/s) | Diameter (m) | 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 7 years, resulting in a unique dataset of in situ atmospheric measurements. Latest results (July 2022): Atmospheric radiation is decreasing in 2022. Our latest measurements in July 2022 registered a 6-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 |  | Marketing yourself on YouTube is hard without real organic views on your videos. You can buy organic YouTube views from and enjoy social boosting that is actually real. Highly recommended! | | When looking for casinos to play online when the weather is bad, you can try the SkyCity Online Casino if you are located in New Zealand. If you are not from NZ you can try the Swedish page Svenska casino online to find suitable games, check out svenskacasinoonline.net. Always check your local laws before playing with real money.. | | BestCSGOGambling is the best site for everything related to CSGO gambling on the web | | | These links help Spaceweather.com stay online. Thank you to our supporters! | | | | | | | | |  | | |  | ©2021 Spaceweather.com. All rights reserved. This site is penned daily by Dr. Tony Phillips. | |
