| | Switch to: Europe, USA, New Zealand, Antarctica Credit: NOAA/Ovation Planetary K-index Now: Kp= 2 quiet 24-hr max: Kp= 4 unsettled explanation | more data Interplanetary Mag. Field Btotal: 5.8 nT Bz: 2.0 nT north more data: ACE, DSCOVR Updated: Today at 2351 UT Coronal Holes: 17 Dec 17 Earth is inside a stream of solar wind flowing from the indicated coronal hole. . Credit: SDO/AIA Noctilucent Clouds Latest images from NASA's AIM spacecraft show that the 2017 northern summer season for noctilucent clouds has finished. Switch view: Europe, USA, Asia, Polar Updated at: 09-03-2017 01:55:03 SPACE WEATHER NOAA Forecasts | | Updated at: 2017 Dec 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: 2017 Dec 18 2200 UTC Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 25 % | 20 % | MINOR | 10 % | 10 % | SEVERE | 01 % | 01 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 15 % | 15 % | MINOR | 30 % | 25 % | SEVERE | 35 % | 30 % | | | | | | | | | | | | All-inclusive Northern Lights trips in Tromsø, Norway. Small groups, big experiences! Highly qualified guides ensure unique and unforgettable adventures with a personal touch. Visit Explore the Arctic | | | SUBSIDING CHANCE OF STORMS: NOAA forecasters have cancelled a geomagnetic storm watch for Dec. 19th. Earth is exiting a stream of solar wind almost a day earlier than expected, tempering expectations for G1-class storming tomorrow. Meanwhile, Arctic sky watchers should remain alert for auroras during the night of Dec. 18-19 as the solar wind continues to blow faster than 500 km/s. Free: Aurora Alerts. SPACE STORM OVER NORWAY: Last night in Kvaløya, Norway, the sky exploded in a spray of color. Aurora tour guide Marianne Bergli caught the outburst: "Everyone was completely speechless," says Bergli. "Then they screamed: Look , WOW, Amazing! It was pink and green and white, is it like that every day?" Indeed, these colors are somewhat unusual. 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. Seldom-seen pink appears when the energetic particles descend lower than usual, striking nitrogen molecules at the 100 km level and below. The ambient solar wind stream seems to be more penetrating than usual, creating an extra-colorful display for Arctic sky watchers. Realtime Aurora Photo Gallery FAR OUT CHRISTMAS GIFTS: Helium doesn't pay for itself. That's why the students of Earth to Sky Calculus fly cool things to the edge of space onboard their cosmic ray balloons--so you can buy them in our Christmas Store: Crystal balls, solar eclipse pendants, pyramids, pickles and much more: they've all been to the edge of space and back, and they all make great holiday gifts. Every dollar spent in the store supports STEM education and high-altitude space weather research. Shop now! Far Out Gifts: Earth to Sky Store All proceeds support hands-on STEM education EMBERS OF A ROCK COMET: The Geminid meteor shower peaked on Dec. 14th when Earth passed through a gravelly stream of debris from rock comet 3200 Phaethon. Worldwide observers working with the International Meteor Organization counted as many as 160 meteors per hour. In the countryside near Portal, Arizona, Alan Dyer photographed dozens of them spraying from the constellation Gemini: "This composite shows the 2017 Geminid meteors streaking from a radiant point in Gemini at upper left, above the blue-white star Castor," explains Dyer. "Two or three meteors are not Geminids. Their paths do not lead back to the radiant, but I have left them in as an illustration. This image also shows meteors appear shorter closer to the radiant and longer away from the radiant." More scenes from the 2017 Geminid meteor shower may be found in our realtime photo gallery. Browse and enjoy! Realtime Space Weather 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 Dec. 18, 2017, the network reported 10 fireballs. (9 sporadics, 1 sigma Hydrid) 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 December 18, 2017 there were 1872 potentially hazardous asteroids. | Recent & Upcoming Earth-asteroid encounters: Asteroid | Date(UT) | Miss Distance | Velocity (km/s) | Diameter (m) | 2017 XS60 | 2017-Dec-12 | 12.8 LD | 19.1 | 20 | 2017 WE13 | 2017-Dec-12 | 16.4 LD | 5.3 | 26 | 2017 VS14 | 2017-Dec-12 | 15.8 LD | 2.8 | 15 | 2017 XU60 | 2017-Dec-13 | 9 LD | 10.2 | 14 | 2017 WJ28 | 2017-Dec-13 | 12.8 LD | 6 | 21 | 2017 XZ61 | 2017-Dec-13 | 3.9 LD | 17.7 | 37 | 2015 XX169 | 2017-Dec-14 | 9.7 LD | 6.3 | 11 | 2006 XY | 2017-Dec-14 | 3.4 LD | 4.9 | 56 | 2017 XY2 | 2017-Dec-15 | 4.5 LD | 8.2 | 14 | 2017 XK1 | 2017-Dec-15 | 6.2 LD | 12.2 | 32 | 2017 XR2 | 2017-Dec-15 | 12.2 LD | 9.4 | 44 | 2017 XD2 | 2017-Dec-15 | 14.4 LD | 12.3 | 69 | 2017 VT14 | 2017-Dec-17 | 3.8 LD | 10.4 | 84 | 2017 XT60 | 2017-Dec-17 | 8 LD | 7 | 12 | 2017 XW60 | 2017-Dec-18 | 5.2 LD | 8.8 | 9 | 2017 XW61 | 2017-Dec-18 | 3.1 LD | 11.7 | 28 | 2017 XX61 | 2017-Dec-18 | 8.2 LD | 15.6 | 17 | 2017 XY61 | 2017-Dec-19 | 2.5 LD | 13.9 | 20 | 2011 YD29 | 2017-Dec-19 | 17.6 LD | 7.7 | 20 | 2017 WX12 | 2017-Dec-21 | 10 LD | 11.4 | 137 | 2017 XR60 | 2017-Dec-21 | 13 LD | 6.2 | 49 | 2017 XQ60 | 2017-Dec-21 | 13.4 LD | 15.7 | 49 | 2017 TS3 | 2017-Dec-22 | 18.1 LD | 10.2 | 137 | 418849 | 2017-Dec-22 | 15.3 LD | 17.4 | 257 | 2015 YQ1 | 2017-Dec-22 | 17.3 LD | 11.1 | 9 | 2017 WZ14 | 2017-Dec-24 | 7.6 LD | 4.9 | 33 | 2017 XG1 | 2017-Dec-29 | 16.4 LD | 9.9 | 38 | 2017 QL33 | 2017-Dec-30 | 13.3 LD | 8.2 | 190 | 2015 RT1 | 2018-Jan-02 | 19.7 LD | 9 | 30 | 2017 XT61 | 2018-Jan-08 | 11.4 LD | 10.8 | 83 | 2004 FH | 2018-Jan-10 | 20 LD | 8.5 | 26 | 306383 | 2018-Jan-22 | 14.4 LD | 17.4 | 178 | 2002 CB19 | 2018-Feb-02 | 10.5 LD | 15.6 | 36 | 276033 | 2018-Feb-04 | 11 LD | 34 | 646 | 2015 BN509 | 2018-Feb-09 | 12.9 LD | 17.7 | 257 | 1991 VG | 2018-Feb-11 | 18.4 LD | 2.1 | 7 | 2014 WQ202 | 2018-Feb-11 | 15.1 LD | 19.8 | 62 | 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 13% 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 | | 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 | | Reviews here can help you to pick up best memory foam mattresses. | | These links help Spaceweather.com stay online. Thank you to our supporters! | | | | | | | | | | | | ©2017 Spaceweather.com. All rights reserved. This site is penned daily by Dr. Tony Phillips. | |