Space Weather Update: 06/04/2016
By Spaceweather.com, 06/04/2016
WEEKEND STORMS ARE LIKELY: NOAA forecasters estimate a 70% chance of geomagnetic storms on June 4th and 5th when a solar wind stream hits Earth’s magnetic field. Deja vu? This stream has been here before. On May 8th (Mother’s Day), it sparked the strongest geomagnetic storm of 2016. During that G3-classevent, auroras were photographed in the USA as far south as Kansas and Arkansas. This time, analysts expect the storm to peak at G2–not as strong as the Mother’s Day Storm, but still worth watching. High-latitude sky watchers should be alert for auroras,especially in the southern hemisphere where darkening autumn skies favor visibility. Aurora alerts: text, voice.
VANISHING SUNSPOTS: Something interesting is happening on the sun. Yesterday, June 3rd, the sunspot number dropped to 0, and the solar disk is still blank on June 4th. Latest images from NASA’s Solar Dynamics Observatory reveal no significant dark cores:
What does this mean? The solar cycle is like a pendulum, swinging back and forth between periods of high and low sunspot number every 11 years. Today’s blank sun is a sign that the pendulum is swinging toward low sunspot numbers. In other words, Solar Minimum is coming.
The spotless state of today’s sun is just temporary. Underneath the visible surface of the sun, the solar dynamo is still churning out knots of magnetism that will soon bob to the surface to make new sunspots. The current solar cycle is not finished. It is, however, rapidly waning.
Forecasters expect the next Solar Minimum to arrive in 2019-2020. Between now and then, there will be lots of spotless suns. At first, the blank stretches will be measured in days; later in weeks and months. Don’t expect space weather to grow quiet, however. Solar Minimum brings many interesting changes. For instance, as the extreme ultraviolet output of the sun decreases, the upper atmosphere of Earth cools and collapses. This allows space junk to accumulate around our planet. Also, the heliosphere shrinks, bringing interstellar space closer to Earth. Galactic cosmic rays penetrate the inner solar system with relative ease. Indeed, a cosmic ray surgeis already underway. Goodbye sunspots, hello deep-space radiation!
THE EDGE OF SPACE IS TURNING ELECTRIC BLUE: NASA’s AIM spacecraft spotted the first noctilucent clouds (NLCs) of the 2016 season on May 24th. Those first clouds were wispy and faint. What a difference a week makes. On June 2nd, a bright display of NLCs wowed observers across the British Isles. Matt Robinson sends this picture from Kielder Observatory in Northumberland, UK:
“The display started at 11pm and we could tell it was going to be a strong one,” says Robinson. “It carried on and got brighter for a further 2 hours. If this is a sign of things to come, this NLC season is going to be one to remember.”
NLCs are Earth’s highest clouds. Seeded by meteoroids, they float at the edge of space more than 80 km above the planet’s surface. Typically, NLCs are brightest in late June and July. A bright display in early June is a good omen indeed.
When noctilucent clouds first appeared in the 19th century, they were confined to Arctic latitudes. In recent years, NLCs have intensified and spread with sightings as far south as Utah and Colorado. This could be a sign of increasing greenhouse gases in Earth’s atmosphere.
Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.
SPACE BALLS FOR FATHER’S DAY: What do you give the Father who has everything? Space Balls! A few days ago, the students of Earth to Sky Calculus flew a basket of space-helmeted golf balls to the edge of space, 36.3 km (119,000 feet) above Earth’s surface on board a high altitude helium balloon:
After the balloon exploded, the balls parachuted back to Earth, landing in the volcanic tablelands north of Bishop CA. For $49.95 you can have one of these balls (space helmet included) along with a unique Father’s Day card showing the balls floating at the top of Earth’s atmosphere. The interior of the card tells the story of the flight and confirms that this gift has been to the edge of space and back again.
All sales support student space weather research. In fact, the balls pictured above were hitchhiking on a payload equipped with radiation sensors. We send the sensors to the stratosphere every week to monitor increasing levels of cosmic rays. Visit the Earth to Sky store to support this crowd-funded research.
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 Jun. 4, 2016, the network reported 16 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 June 4, 2016 there were 1704 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:Asteroid
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
Situation Report — Oct. 30, 2015Stratospheric Radiation (+37o N)
Cosmic ray levels are elevated(+6.1% above the Space Age median). The trend is flat. Cosmic ray levels have increased +0% in the past month.
Sept. 06: 4.14 uSv/hr (414 uRad/hr)
Sept. 12: 4.09 uSv/hr (409 uRad/hr)
Sept. 23: 4.12 uSv/hr (412 uRad/hr)
Sept. 25: 4.16 uSv/hr (416 uRad/hr)
Sept. 27: 4.13 uSv/hr (413 uRad/hr)
Oct. 11: 4.02 uSv/hr (402 uRad/hr)
Oct. 22: 4.11 uSv/hr (411 uRad/hr)
These measurements are based on regular space weather balloon flights: learn more.
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. Our measurements show that someone flying back and forth across the continental USA, just once, can absorb as much ionizing radiation as 2 to 5 dental X-rays. For example, here is the data from a flight on Oct. 22, 2015:
Radiation levels peak at the entrance to the stratosphere in a broad region called the “Pfotzer Maximum.” This peak is named after physicist George Pfotzer who discovered it using balloons and Geiger tubes in the 1930s. Radiation levels there are more than 80x sea level.
Note that the bottom of the Pfotzer Maximim is near 55,000 ft. This means that some high-flying aircraft are not far from the zone of maximum radiation. Indeed, according to the Oct 22th measurements, a plane flying at 45,000 feet is exposed to 2.79 uSv/hr. At that rate, a passenger would absorb about one dental X-ray’s worth of radiation in about 5 hours.
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.
speed: 298.6 km/sec
density: 5.0 protons/cm3
explanation | more data
Updated: Today at 1950 UTX-ray Solar Flares
6-hr max: B1 1540 UT Jun04
24-hr: B1 0813 UT Jun04
explanation | more data
Updated: Today at: 1900 UTDaily Sun: 04 Jun 16For the first time in almost two years, the sun is blank–no sunspots! Credit: SDO/HMI
Sunspot number: 0
What is the sunspot number?
Updated 04 Jun 2016
Current Stretch: 1 days
2016 total: 1 days (<1%)
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 04 Jun 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 1 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 4.0 nT
Bz: 3.7 nT north
explanation | more data
Updated: Today at 1950 UTCoronal Holes: 04 Jun 16Solar wind flowing from the indicated coronal hole could reach Earth late on June 4th, although June 5th or 6th seems more likely. Credit: SDO/AIA.Noctilucent Clouds Images from NASA’s AIM spacecraft are once again appearing on Spaceweather.com. Check back daily for space-based sightings of noctilucent clouds.
Switch view: Europe, USA, Asia, PolarUpdated at: 06-04-2016 15:55:02
Updated at: 2016 Jun 03 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2016 Jun 03 2200 UTCMid-latitudes