Space Weather Update: 03/01/2017
By Spaceweather.com, 03/01/2017
SUNSET PLANETS: When the sun goes down tonight, step outside and look west. Venus, Mars and the crescent Moon are shining together in the sunset sky. The Moon and Venus appear first, surrounded by twilight blue; Mars joins the show as the sky darkens. The Red Planet is right beside the crescent Moon: sky map.
THE SOLAR WIND HAS ARRIVED: As predicted, Earth has entered a stream of fast-moving solar wind on March 1st. First contact with the stream sparked bright green auroras over Alaska. Ayumi Bakken sends this picture from the countryside near Fairbanks:
"What an amazing show tonight," says Bakken. "Just after a winter storm passed, the magnetic storm began and Lady Aurora danced overhead."
Earth is moving deeper into the stream, and wind speeds could top 700 km/s before the day is over. Arctic sky watchers should remain alert for auroras on Mar. 1-2 asNOAA forecasters estimate a 60% chance of continued polar geomagnetic storms. Free: Aurora alerts.
VENUS IS A CRESCENT: Lately, have you noticed an intensely bright star in the western sky at sunset? That's no star, it's a planet: Venus. And if you look at it with a small telescope, you might get another surprise. Venus is a crescent. Shahrin Ahmad of Kuala Lumpur, Malaysia, photographed the phenomenon on Feb. 28th:
"Venus now is shining at only 17.6%," says Ahmad. "We are only about 26 days before inferior conjunction."
Inferior conjunction is the reason for Venus's shape. On March 25th, Venus will pass almost directly between Earth and the sun--i.e., "inferior conjunction." As it approaches that point, Venus is turning its nightside toward Earth, leaving only a crescent-shaped sliver of dayside visible from our location on planet #3.
Amateur astronomers are encouraged to monitor Venus in the lead-up to inferior conjunction. In the nights ahead, the crescent of Venus will become increasingly thin and circular. The horns of the crescent might actually touch when the Venus-sun angle is least on March 25th. Stay tuned for that.
ARCTIC SPACE REINDEER: The students of Earth to Sky Calculus are about to travel inside the Arctic Circle (Abisko, Sweden) for their first polar space weather balloon launch. To raise money for the trip, on Feb. 23rd they flew a payload-full of Arctic reindeer pendants to the edge of space:
You can have one for $129.95. Each glittering pendant comes with a greeting card showing the jewelry in flight and certifying that it has been to the stratosphere and back again. These pendants make great Birthday and Mother's Day gifts.
Bonus: Would you like your pendant to be flown over the Arctic as well? Make a note to that effect in the COMMENTS box at checkout, and we will take your pendent to Sweden for a second trip to the stratosphere.
All Sky Fireball Network
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 Mar. 1, 2017, the network reported 6 fireballs.
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 March 1, 2017 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
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 12% 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.
Daily Sun: 01 Mar 17
Suddenly, the region around sunspot AR2641 is crowded with dark cores. This rapidly changing sunspot could soon pose a threat for flares if its growth proceeds apace. Credit: SDO/HMI
Sunspot number: 39
What is the sunspot number?
Updated 01 Mar 2017
Current Stretch: 0 days
2017 total: 11 days (19%)
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 01 Mar 2017
The Radio Sun
10.7 cm flux: 82 sfu
explanation | more data
Updated 01 Mar 2017
Current Auroral Oval:
Coronal Holes: 01 Mar 17
Earth is inside a stream of solar wind flowing from the indicated coronal hole. Credit: NASA/SDO.
Noctilucent Clouds The southern season for noctilucent clouds began on Nov. 17, 2016. Come back to this spot every day to see the "daily daisy" from NASA's AIM spacecraft, which is monitoring the dance of electric-blue around the Antarctic Circle.
Updated at: 02-24-2017 17:55:02
Updated at: 2017 Feb 28 2200 UTC
Updated at: 2017 Feb 28 2200 UTC