| | Switch to: Europe, USA, New Zealand, Antarctica Credit: NOAA/Ovation Planetary K-index Now: Kp= 1 quiet 24-hr max: Kp= 1 quiet explanation | more data Interplanetary Mag. Field Btotal: 5.9 nT Bz: -5.1 nT south more data: ACE, DSCOVR Updated: Today at 2351 UT Coronal Holes: 23 Jul 18 Solar wind flowing from this large coronal hole should reach Earth on July 24th. Credit: SDO/AIA Noctilucent Clouds The season for noctilucent clouds in he northern hemisphere is underway. Check here daily for the latest images from NASA's AIM spacecraft. Switch view: Europe, USA, Asia, Polar Updated at: 07-23-2018 14:55:02 SPACE WEATHER NOAA Forecasts | | Updated at: 2018 Jul 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: 2018 Jul 23 2200 UTC Mid-latitudes | 0-24 hr | 24-48 hr | ACTIVE | 40 % | 30 % | MINOR | 30 % | 15 % | SEVERE | 05 % | 01 % | High latitudes | 0-24 hr | 24-48 hr | ACTIVE | 05 % | 15 % | MINOR | 20 % | 30 % | SEVERE | 65 % | 45 % | | | | | | | | | | | | 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 | | | SPOTLESS SUN: Over the weekend, a small sunspot (AR2716) ended a 24-day string of blank suns. The interruption was brief. After only one day, the sunspot has dissolved and the spotless days counter is ticking again: 112 days so far in 2018 without sunspots. It's been 9 years since sunspots were this scarce, a sign that solar minimum has arrived. Free: Aurora Alerts. NOCTILUCENT RADIO ECHOES: High above the Arctic Circle, the glow of the midnight sun prevents observers from seeing night-shining (noctilucent) clouds--even though the clouds are directly overhead. Rob Stammes of Lofoton, Norway, is under that dome of sunlight. He detects noctilucent clouds using radio waves. Last night, July 22-23, there was quite an outburst: "I had the strongest Polar Mesospheric Summer Echo signals on my instruments this season," says Stammes. "The signals could be heard for a long time." Polar Mesospheric Summer Echoes (PMSEs) are terrestrial radio stations reflected from an altitude of 80 km to 90 km--the same place noctilucent clouds are found. The exact cause of PMSEs is not yet known. Theorists have proposed explanations ranging from steep electron density gradients and "dressed aerosols" to gravity waves and turbulence. Strong echoes are almost always accompanied by visible noctilucent clouds. Indeed, Stammes notes a number of entries in the Noctilucent Cloud Photo Gallery around the time of the outburst. "The relation between radio PMSEs and visible noctilucent clouds was very clear last night," he says. Realtime Noctilucent Cloud Photo Gallery GEOMAGNETIC STORM PREDICTED: NOAA forecasters say there is a 65% chance of minor G1-class geomagnetic storms on July 24th when a high-speed stream of solar wind is expected to hit Earth's magnetic field. The gaseous material is flowing from a large hole in the sun's atmosphere, shown here in an extreme ultraviolet image from NASA's Solar Dynamics Observatory: This is a "coronal hole," a vast region in the sun's atmosphere where magnetic fields open up and allow solar wind to escape. They look dark in ultraviolet images because the hot glowing plasma normally contained there is missing. In this case, the plasma is making a beeline for Earth. Some readers have asked, how can we have a geomagnetic storm during solar minimum? It happens all the time. Sunspots, whose counts define the solar cycle, are not the only source of storms. When sunspots vanish, coronal holes replace them as a primary source of solar activity. Studies show that coronal holes not only open more frequently, but also last longer when sunspots are absent. During the last solar minimum in 2007-2009, one coronal hole stayed open for 27 consecutive solar rotations. As the sun slowly turned on its axis, that hole fire-hosed Earth with a stream of solar wind almost once a month for nearly two years. Explosive sunspots make stronger storms than the relatively gentle breezes that emerge from coronal holes, but geomagnetic storms never go away, not even during solar minimum. High-latitude sky watchers should be alert for auroras on July 24th when the solar wind arrives. G1-class storms can produce Northern Lights as far south as US states ranging from Maine to Washington. Free: Aurora Alerts. Realtime Aurora Photo Gallery FLY ME TO THE MOONSTONE: Are you looking for a far-out gift? Nothing says "I love you" like a moonstone from the edge of space. On June 12th, the students of Earth to Sky Calculus flew this moonstone wrapped in a sterling silver Celtic love knot 34.1 km (111,877 feet) above Earth's surface: You can have it for $119.95. The students are selling these pendants to support their cosmic ray ballooning program. Each one comes with a greeting card showing the item in flight and telling the story of its journey to the edge of space. Sales support the Earth to Sky Calculus cosmic ray ballooning program and hands-on STEM research. Far Out Gifts: Earth to Sky Store All sales support hands-on STEM education 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 Jul. 23, 2018, the network reported 12 fireballs. (11 sporadics, 1 alpha Capricornid) 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 July 23, 2018 there were 1912 potentially hazardous asteroids. | Recent & Upcoming Earth-asteroid encounters: Asteroid | Date(UT) | Miss Distance | Velocity (km/s) | Diameter (m) | 2018 NL4 | 2018-Jul-18 | 10.4 LD | 12.7 | 53 | 2018 OQ | 2018-Jul-18 | 3.7 LD | 6.1 | 17 | 2018 NQ1 | 2018-Jul-19 | 16.4 LD | 6 | 32 | 2018 OF | 2018-Jul-19 | 14.7 LD | 14 | 49 | 2018 NE1 | 2018-Jul-21 | 10.1 LD | 14.2 | 73 | 2018 NF4 | 2018-Jul-21 | 18.8 LD | 12.8 | 114 | 2018 OL | 2018-Jul-22 | 11.5 LD | 16.1 | 57 | 2018 NR1 | 2018-Jul-27 | 17.1 LD | 5.1 | 35 | 2018 LQ2 | 2018-Aug-27 | 9.4 LD | 1.5 | 39 | 2016 GK135 | 2018-Aug-28 | 16.8 LD | 2.8 | 9 | 2016 NF23 | 2018-Aug-29 | 13.3 LD | 9 | 93 | 1998 SD9 | 2018-Aug-29 | 4.2 LD | 10.7 | 51 | 2018 DE1 | 2018-Aug-30 | 15.2 LD | 6.5 | 28 | 2001 RQ17 | 2018-Sep-02 | 19.3 LD | 8.3 | 107 | 2015 FP118 | 2018-Sep-03 | 12.3 LD | 9.8 | 490 | 2017 SL16 | 2018-Sep-20 | 8.5 LD | 6.4 | 25 | 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 | | To find reviews of new online casino sites in the UK try The Casino DB where there are hundreds of online casino reviews complete with bonuses and ratings. | | 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. | |