![](site_images/left_table_top.jpg) | | Switch to: Europe, USA, New Zealand, Antarctica Credit: NOAA/Ovation Planetary K-index Now: Kp= 2 quiet 24-hr max: Kp= 3 quiet explanation | more data Interplanetary Mag. Field Btotal: 2.9 nT Bz: -1.5 nT south more data: ACE, DSCOVR Updated: Today at 2350 UT Coronal Holes: 07 Dec 17 ![](images2017/07dec17/coronalhole_sdo_200.gif) Solar wind flowing from the indicated coronal hole should reach Earth on Dec. 11th or 12th. 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 07 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 07 2200 UTC Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 15 % | 10 % | MINOR | 05 % | 01 % | SEVERE | 01 % | 01 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 20 % | 15 % | MINOR | 20 % | 15 % | SEVERE | 20 % | 10 % | | | | ![](site_images/left_tablebg_bottom.jpg) | | | | | | | | Lights Over Lapland is excited to announce that we now have TWO aurora webcams covering nearly a 200° view of Abisko National Park in Sweden! Watch the auroras dance live, all season long here. | | | STRUGGLING SUNSPOT: A new sunspot (AR2690) emerged on Dec. 6th, breaking a string of 5 spotless days. Today, Dec. 7th, it is already fading away: 24-hr movie. Sunspots tend to struggle during the declining phase of the solar cycle, and this one is no exception. It will likely be gone tomorrow. Free: Aurora Alerts. WHEN WILL THE NEXT STREAM OF SOLAR WIND ARRIVE? On Dec. 6th, as Earth was exiting a fast-moving stream of solar wind, a subsiding tremor of magnetic activity sparked bright auroras over Abisko, Sweden. David Williams witnessed the display as it emerged over the crest of Mt. Nouljia: ![](images2017/07dec17/greenring_strip.jpg) "Our Lights Over Lapland tour group arrived at the Aurora Sky Station at about 10pm," says Williams. "No sooner had we set up our cameras when these intense auroras formed apparently just up the mountainside." Now the onlookers of that amazing display are wondering, when will it happen again? As Earth exits one stream of solar wind, another is on the way. Estimated time of arrival: Dec. 10th or 11th. The stream of gaseous material is flowing from a canyon-shaped hole in the sun's atmosphere stretching down from the sun's north pole. Minor geomagnetic storms and bright Arctic auroras are possible when the solar wind arrives. Realtime Aurora Photo Gallery ATMOSPHERIC RADIATION IS INCREASING: Since the spring of 2015, Spaceweather.com and the students of Earth to Sky Calculus have been flying balloons to the stratosphere over California to measure cosmic rays. Soon after our monitoring program began, we quickly realized that radiation levels are increasing. Why? The main reason is the solar cycle. In recent years, sunspot counts have plummeted as the sun's magnetic field weakens. This has allowed more cosmic rays from deep space to penetrate the solar system. As 2017 winds down, our latest measurements show the radiation increase continuing apace--with an interesting exception, circled in yellow: ![](images2017/06dec17/stratosphere_29nov17_strip.png) In Sept. 2017, the quiet sun surprised space weather forecasters with a sudden outburst of explosive activity. On Sept. 3rd, a huge sunspot appeared. In the week that followed, it unleashed the strongest solar flare in more than a decade (X9-class), hurled a powerful CME toward Earth, and sparked a severe geomagnetic storm (G4-class) with Northern Lights appearing as far south as Arkansas. During the storm we quickened the pace of balloon launches and found radiation dropping to levels we hadn't seen since 2015. The flurry of solar flares and CMEs actually pushed some cosmic rays away from Earth. Interestingly, after the sun's outburst, radiation levels in the stratosphere took more than 2 months to fully rebound. Now they are back on track, increasing steadily as the quiet sun resumes its progress toward Solar Minimum. The solar cycle is not expected to hit rock bottom until 2019 or 2020, so cosmic rays should continue to increase, significantly, in the months and years ahead. Stay tuned for updates as our balloons continue to fly. Technical note: The radiation sensors onboard our helium balloons detect X-rays and gamma-rays in the energy range 10 keV to 20 MeV. These energies, which span the range of medical X-ray machines and airport security scanners, trace secondary cosmic rays, the spray of debris created when primary cosmic rays from deep space hit the top of Earth's atmosphere. Realtime Space Weather 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 on board their cosmic ray balloons--so you can buy them in our Christmas Store: ![](images2017/03dec17/gifts_strip.png) 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 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. 7, 2017, the network reported 14 fireballs. (12 sporadics, 1 Geminid, 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 7, 2017 there were 1869 potentially hazardous asteroids. ![](site_images/spacer.gif) | Recent & Upcoming Earth-asteroid encounters: Asteroid | Date(UT) | Miss Distance | Velocity (km/s) | Diameter (m) | 2008 WM61 | 2017-Dec-02 | 3.7 LD | 4.7 | 16 | 2017 WH16 | 2017-Dec-03 | 17.4 LD | 15.2 | 26 | 2017 WZ27 | 2017-Dec-03 | 13.6 LD | 4.2 | 11 | 2017 WS13 | 2017-Dec-05 | 9.5 LD | 11.3 | 42 | 2017 WF28 | 2017-Dec-06 | 17.6 LD | 7.6 | 21 | 2017 WV12 | 2017-Dec-09 | 3.4 LD | 10.6 | 26 | 2017 WE13 | 2017-Dec-12 | 16.4 LD | 5.4 | 26 | 2017 VS14 | 2017-Dec-12 | 15.9 LD | 2.8 | 15 | 2017 WJ28 | 2017-Dec-13 | 12.9 LD | 6.1 | 21 | 2015 XX169 | 2017-Dec-14 | 9.7 LD | 6.3 | 11 | 2006 XY | 2017-Dec-14 | 3.4 LD | 4.9 | 56 | 2017 VT14 | 2017-Dec-17 | 3.8 LD | 10.4 | 105 | 2011 YD29 | 2017-Dec-19 | 17.6 LD | 7.7 | 20 | 2017 WX12 | 2017-Dec-21 | 10.1 LD | 11.4 | 126 | 2017 TS3 | 2017-Dec-22 | 18.1 LD | 10.2 | 138 | 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 | 32 | 2017 QL33 | 2017-Dec-30 | 13.3 LD | 8.2 | 190 | 2015 RT1 | 2018-Jan-02 | 19.7 LD | 9 | 30 | 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 | 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: ![](cosmicrays/everything_11sep16_strip.png) 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: ![](images2017/12may17/radplot_strip.png) 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 | ![](site_images/link_button_graphic.gif) | Reviews here can help you to pick up best memory foam mattresses. | | These links help Spaceweather.com stay online. Thank you to our supporters! | | | | | | | | ![](site_images/center_tablebg_bottom.jpg) | | ![](site_images/spacer.gif) | ![](site_images/spacer.gif) | ©2017 Spaceweather.com. All rights reserved. This site is penned daily by Dr. Tony Phillips. | |