Spotless Days Current Stretch: 0 days 2018 total: 132 days (56%) 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%) 2008 total: 268 days (73%) 2007 total: 152 days (42%) 2006 total: 70 days (19%) Updated 23 Aug 2018
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 Aug 23 2200 UTC
Thursday, Aug. 23, 2018
What's up in space
Lights Over Lapland has a brand-new website full of exciting adventures in Abisko National Park, Sweden! Take a look at our aurora activities and book your once-in-a-lifetime trip with us today!
POSSIBLE CME IMPACT THIS WEEK: Earth's magnetic field could become unsettled on Aug. 24th or 25th when a slow-moving coronal mass ejection (CME) reaches our planet. There is much uncertainty about this CME. NASA and ESA satellites saw the solar storm cloud leave the sun on Aug. 21st, but they could not pinpoint its source on the solar disk, nor could they precisely determine its trajectory. If the CME does indeed hit Earth, it could spark auroras around the Arctic Circle. Free:Aurora Alerts.
A SPACESHIP IN FRONT OF THE SUN: Yesterday, the biggest sunspot on the sun was not a sunspot at all. It was a 450-ton spaceship with wings wider than a 747 jet--in other words, the International Space Station (ISS). Maximilian Teodorescu watched the ISS flit across the surface of the sun on August 22nd:
"I was very lucky to catch the split-second transit through a small opening in the clouds above Magurele, Romania," says Teodorescu. "The seeing was not great, but solar granulation is discernible as well as a few structural details in the station's silhouette. I knew when to look thanks to predictions from Calsky.com."
Now that the space station has passed by, the disk of the sun is almost entirely blank, interrupted only by the scattered dark cores of actual sunspot AR2719. AR2719 is small and quiet--typical of sunspots during solar minimum. Solar observers wishing to see some action may wish to check Calsky for future passes of the ISS.
CHINESE SPACECRAFT FLIES BY BETELGEUSE: Earlier this year, the Chinese space station Tiangong-1 made headlines when it crashed into the south Pacific Ocean. Often forgotten is Tiangong-1's sister craft, Tiangong-2, which is still in orbit. Last night, Kevin Fetter of Brockville, Ontario, recorded the bus-sized spacecraft gliding by Betelgeuse, a red supergiant star in the constellation Orion:
Tiangong-2 is an unmanned space station, but it has not always been unoccupied. Chinese astronauts Jing Haipeng and Chen Dong boarded Tiangong-2 in Oct. 2016 and lived there for 30 days, conducting experiments in human physiology and practicing procedures for in-orbit rendezvous and docking.
Tiangong-2 was never intended to be a permanent station. Instead, the Chinese space agency is using it as practice for the Chinese large modular space station, which is reportedly planned for launch between 2019 and 2022.
In June 2018, Tiangong 2 maneuvered closer to Earth, apparently in preparation for deorbiting. However, it has since returned to its usual orbit. Readers, if you would like to see Tianging-2 for yourself, flyby predictions are available from Heavens Above.
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 Jan 27th, the students of Earth to Sky Calculus flew this moonstone wrapped in a hand-crafted sterling silver Celtic love knot 35.1 km (115,158 feet) above Earth's surface:
You can have it for $179.95. 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. All sales 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 Aug. 23, 2018, the network reported 37 fireballs. (36 sporadics, 1 kappa Cygnid)
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 August 23, 2018 there were 1912 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
SPACE WEATHER BALLOON DATA: 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 18% since 2015:
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.
En route to the stratosphere, our sensors also pass through aviation altitudes:
In this plot, 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.
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.
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.