Spotless Days Current Stretch: 0 days 2018 total: 7 days (41%) 2017 total: 104 days (28%) 2016 total: 32 days (9%) 2015 total: 0 days (0%) 2014 total: 1 day (<1%) 2013 total: 0 days (0%) 2012 total: 0 days (0%) 2011 total: 2 days (<1%) 2010 total: 51 days (14%) 2009 total: 260 days (71%) Updated 17 Jan 2018
Interplanetary Mag. Field Btotal: 4.3 nT Bz: 1.7 nT north more data: ACE, DSCOVR Updated: Today at 2351 UT
Coronal Holes: 17 Jan 18
Solar wind flowing from the indicated coronal hole should reach Earth on Jan. 20th, sparking G1-class geomagnetic storms. Credit: SDO/AIA
Noctilucent CloudsOur connection with NASA's AIM spacecraft has been restored! New images from AIM show that the southern season for noctilucent clouds (NLCs) is underway. Come back to this spot every day to see AIM's "daily daisy," which reveals the dance of electric-blue NLCs around the Antarctic Circle..
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 Jan 17 2200 UTC
Wednesday, Jan. 17, 2018
What's up in space
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AURORA FORECAST: A hole in the sun's atmosphere is turning toward Earth and blowing a stream of solar wind toward our planet. Estimated time of arrival: Jan. 20th. Polar geomagnetic storms (G1-class) and Arctic auroras are therefore possible this weekend. Free:Aurora Alerts.
METEOR EXPLODES OVER MICHIGAN (UPDATED): Sonic booms, rattling windows, and a bright flash of light washed over Michigan and surrounding states Tuesday evening when a meteoroid exploded in the atmosphere over the Great Lakes region of the USA. This video from a backyard security camera in southeastern Michigan shows the snowy landscape brightening like day during a rapid double-flash in the sky overhead:
So far, the International Meteor Organization has received almost 400 reports of the explosion from observing sites in Michigan, Illinois, Pennsylvania, Ohio, Indiana, Wisconsin, Ontario, and Iowa, most agreeing that the explosion occured around 8:10 pm local time on Jan. 16th (01:10 UT on Wednesday, Jan. 17th).
This shadow-casting fireball was brighter than the full Moon and it produced loud sonic booms – a sign that it penetrated deep in the atmosphere and may have dropped meteorites on the ground. Indeed, the USGS says the explosion may have caused a magnitude 2.0 earthquake. Stay tuned for updates about this event as more information becomes available.
MAMMATUS AURORAS: Auroras come in many forms: curtains, rays, arcs, etc. On Jan. 15th. James Helmericks of Alaska may have spotted a new one: the "Mammatus Aurora." He sends this picture from the Colville River Delta:
"This is the first time I have observed this type of formation and it reminded me of mammatus clouds," says Helmericks. "The display lasted about an hour. Towards the end the small puffs merged into a more solid formation."
These puffy "mammatus" formations may be disorganized cousins of picket fence auroras, in which beams of electrons rain down on Earth's upper atmosphere, creating evenly-space columns of green and yellow light. Plasma waves and magnetic cavities in Earth's magnetosphere can help organize these structures, although the details are not well understood. For now, add "mammatus" to the catalogue of auroral forms -- and stay tuned for more sightings as northern winter unfolds.
VALENTINE'S DAY IS COMING: Nothing says "I Love You" like a Valentine's pendant from the edge of space. On Dec. 31, 2017, the students of Earth to Sky Calculus flew a payload-full of these heart-shaped pendants to the stratosphere, 35.1 km (115,158 feet) above Earth's surface:
You can 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 edge of space. Sales of this pendant support the Earth to Sky Calculus cosmic ray ballooning program and hands-on STEM research.
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 Jan. 17, 2018, the network reported 12 fireballs. (12 sporadics)
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]
Near Earth Asteroids
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 January 17, 2018 there were 1882 potentially hazardous asteroids.
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.