| | Switch to: Europe, USA, New Zealand, Antarctica Credit: NOAA/Ovation Planetary K-index Now: Kp= 4 unsettled 24-hr max: Kp= 6 storm explanation | more data Interplanetary Mag. Field Btotal: 5.5 nT Bz: -0.2 nT south more data: ACE, DSCOVR Updated: Today at 0005 UT Coronal Holes: 23 Apr 17 Earth is entering a stream of solar wind flowing from this large coronal hole. Credit: NASA/SDO. Noctilucent Clouds The southern season for noctilucent clouds began on Nov. 17, 2016. Come back to this spot every day to see the "daily daisy" from NASA's AIM spacecraft, which is monitoring the dance of electric-blue around the Antarctic Circle. Switch view: Ross Ice Shelf, Antarctic Peninsula, East Antarctica, Polar Updated at: 02-24-2017 17:55:02 SPACE WEATHER NOAA Forecasts | | Updated at: 2017 Apr 23 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: 2017 Apr 23 2200 UTC Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 45 % | 40 % | MINOR | 25 % | 25 % | SEVERE | 01 % | 01 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 10 % | 10 % | MINOR | 25 % | 25 % | SEVERE | 65 % | 60 % | | | | | | | | | | | | Looking for a far-out Mother's Day gift? Find something truly out of this world in the Earth to Sky Store. Space roses, Cosmic Reindeer, Arctic space pendants, and more! | | | EXPLOSION ON THE SUN: On April 23rd around 0500 UT, a dark filament of magnetism on the sun exploded. See the movie from NASA's Solar Dynamics Observatory. An analysis is underway to determine if any portion of the debris is heading for Earth. Stay tuned. SOLAR WIND STORM: A solar wind storm is underway around Earth as our planet enters a high-speed stream of gas flowing from a large hole in the sun's atmosphere. NASA's Solar Dynamics Observatory photographed the source of the wind on April 23rd: This is a coronal hole (CH)--a place in the sun's atmosphere where the magnetic field peels back and allows solar wind to escape. Solar wind flowing from this hole is moving faster than 700 km/s--a veritable gale. Moreover, the wind is threaded with "negative polarity" magnetic fields. Such fields do a good job connecting to Earth's magnetosphere and energizing geomagnetic storms. NOAA forecasters estimate a 80% chance of polar geomagnetic storms on April 23rd subsiding to 'only' 60% to 65% on April 24th and 25th as Earth moves through this potent stream of solar wind. High-latitude sky watchers should remain alert for auroras. Free: Aurora Alerts Realtime Space Weather Photo Gallery EARTH DAY AURORA SURPRISE: A bright CME that left the sun on April 19th was supposed to miss Earth. Instead, 3 days later, it hit, sparking a surprise display of auroras for Earth Day. Ayumi Bakken recorded this outburst of lights just outside Fairbanks, Alaska: "It looked like a big 'dragon rage'," says Bakken. "Amazing pink and purple colored auroras painted the spring dawn sky." Most auroras are green--a verdant glow caused by energetic particles from space hitting oxygen atoms 100 km to 300 km above Earth's surface. On Earth Day, however, the auroras outside Fairbanks were strongly fringed with pink. This is a sign of a different element. Pink appears when energetic particles descend lower than usual, striking nitrogen molecules at the 100 km level and below. Pinks, purples, reds and many other colors were witnessed on Earth Day as G1- and G2-class geomagnetic storms lit up the poles at both ends of our planet. Browse the aurora gallery for sightings. Realtime Aurora Photo Gallery THESE PENDANTS HAVE TOUCHED SPACE: These pendants have touched space--and returned to Earth in time for Mother's Day. On April 15, 2017, the students of Earth to Sky Calculus flew a payload-full of heart-shaped Venus pendants to the stratosphere onboard a high-altitude helium balloon. Here's one, 111,550 feet above the Sierras of central California: These blue jewels make great Mother's Day gifts--and you have have one for $99.95. Each glittering pendant comes with a greeting card showing the jewelry in flight and telling the story of its journey to the stratosphere and back again. More far-out Mother's Day gifts may be found in the Earth to Sky Store. All proceeds support atmospheric radiation monitoring and hands-on STEM education. Realtime Comet Photo Gallery 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. 23, 2017, the network reported 30 fireballs. (19 sporadics, 11 April 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 23, 2017 there were 1798 potentially hazardous asteroids. | Recent & Upcoming Earth-asteroid encounters: Asteroid | Date(UT) | Miss Distance | Velocity (km/s) | Diameter (m) | 2017 GO4 | 2017-Apr-15 | 13.8 LD | 6 | 34 | 2014 UR | 2017-Apr-19 | 18.8 LD | 4.4 | 17 | 2014 JO25 | 2017-Apr-19 | 4.6 LD | 33.6 | 852 | 2017 GL4 | 2017-Apr-20 | 17.5 LD | 7.4 | 22 | 2017 GM4 | 2017-Apr-20 | 13.1 LD | 16.6 | 143 | 2017 FH101 | 2017-Apr-24 | 18.8 LD | 9.9 | 103 | 2017 FE157 | 2017-Apr-29 | 18.6 LD | 8.6 | 64 | 2015 VD1 | 2017-May-07 | 18.2 LD | 10.5 | 34 | 2012 EC | 2017-May-16 | 19.5 LD | 4.5 | 74 | 2017 CS | 2017-May-29 | 8 LD | 9.1 | 468 | 418094 | 2017-Jun-01 | 8 LD | 23.2 | 490 | Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach. | Cosmic Rays in the Atmosphere | Readers, thank you for your patience while we continue to develop this new section of Spaceweather.com. We've been working to streamline our data reduction, allowing us to post results from balloon flights much more rapidly, and we have developed a new data product, shown here: This plot displays radiation measurements not only in the stratosphere, but also at aviation altitudes. Dose rates are expessed as multiples of sea level. For instance, we see that boarding a plane that flies at 25,000 feet exposes passengers to dose rates ~10x higher than sea level. At 40,000 feet, the multiplier is closer to 50x. These measurements are made by our usual cosmic ray payload as it passes through aviation altitudes en route to the stratosphere over California. What is this all about? Approximately 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 radiation sensors that detect cosmic rays, a surprisingly "down to Earth" form of space weather. Cosmic rays can seed clouds, trigger lightning, and penetrate commercial airplanes. Furthermore, there are studies ( #1, #2, #3, #4) linking cosmic rays with cardiac arrhythmias and sudden cardiac death in the general population. Our latest measurements show that cosmic rays are intensifying, with an increase of more than 12% since 2015: Why are cosmic rays intensifying? The main reason is the sun. Solar storm clouds such as coronal mass ejections (CMEs) sweep aside cosmic rays when they pass by Earth. During Solar Maximum, CMEs are abundant and cosmic rays are held at bay. Now, however, the solar cycle is swinging toward Solar Minimum, allowing cosmic rays to return. Another reason could be the weakening of Earth's magnetic field, which helps protect us from deep-space radiation. 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. The data points in the graph above correspond to the peak of the Reneger-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 Reneger 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. | | from the NOAA Space Environment Center | | a proud supporter of science education and Spaceweather.com | | 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 | | Beautyz for top beauty products reviews and their buying guides | | Reviews here can help you to pick up best memory foam mattresses. | | These links help Spaceweather.com stay online. Thank you to our supporters! | | | | | | | | | | | | ©2016 Spaceweather.com. All rights reserved. This site is penned daily by Dr. Tony Phillips. | |