You are viewing the page for Sep. 26, 2015
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids Internet Shopping Sites high quality binoculars excellent weather stations all-metal reflector telescopes rotatable microscopes
Solar wind
speed: 409.9 km/sec
density: 4.6 protons/cm3
explanation | more data
Updated: Today at 2351 UT
X-ray Solar Flares
6-hr max: B7
2034 UT Sep26
24-hr: C1
0129 UT Sep26
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 26 Sep 15
Fast-growing sunspot AR2422 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. Credit: SDO/HMI

Sunspot number: 145
What is the sunspot number?
Updated 26 Sep 2015

Spotless Days
Current Stretch: 0 days
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 26 Sep 2015

The Radio Sun
10.7 cm flux: 120 sfu
explanation | more data
Updated 26 Sep 2015

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 2
explanation | more data
Interplanetary Mag. Field
Btotal: 4.8 nT
Bz: 0.5 nT south
explanation | more data
Updated: Today at 2350 UT
Coronal Holes: 26 Sep 15

There are no large coronal holes on the Earhside of the sun. Credit: SDO/AIA.
Noctilucent Clouds The northern season for NLCs is finished. According to NASA's AIM spacecraft, the last clouds were observed over Greenland on Aug. 27th. Now the waiting begins for the southern season expected to begin in November.
Switch view: Europe, USA, Asia, Polar
Updated at: 09-01-2015 09:00:00
NOAA Forecasts
Updated at: 2015 Sep 26 2200 UTC
0-24 hr
24-48 hr
40 %
40 %
05 %
05 %
Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2015 Sep 26 2200 UTC
0-24 hr
24-48 hr
10 %
10 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
20 %
25 %
25 %
20 %
20 %
Saturday, Sep. 26, 2015
What's up in space

On Sept. 27th, the Harvest Moon will pass through the shadow of Earth, turning the lunar disk a lovely shade of celestial red. Catch it live on the Internet, courtesy of the Coca-Cola Space Science Center in Columbus, Georgia.

Eclipse Webcast

SUPERMOON ECLIPSE: This weekend's full Moon is a supermoon, the biggest and brightest full Moon of the year. And it is going to be eclipsed. On Sunday evening, Sept. 27th, the supermoon will pass through the shadow of Earth, turning the lunar disk a coppery shade of red. Click on the image, below, to view an animation of the eclipse and to find out when to look:

Sky watchers in the Americas, Europe, Africa, and eastern parts of Asia can see the event. The next total eclipse of the Moon won't come until January 31, 2018, so if you live in the eclipse zone, check it out.

What makes the eclipsed Moon turn red? A quick trip to the Moon provides the answer: Imagine yourself standing on a dusty lunar plain looking up at the sky. Overhead hangs Earth, nightside down, completely hiding the sun behind it. The eclipse is underway.

You might expect Earth seen in this way to be utterly dark, but it's not. The rim of the planet looks like it is on fire. As you scan your eye around Earth's circumference, you're seeing every sunrise and every sunset in the world, all of them, all at once. This incredible light beams into the heart of Earth's shadow, filling it with a coppery glow and transforming the Moon into a great red orb.

Red isn't the only color. There's also turquoise, shown here in a photo taken by Jens Hackman during an eclipse in March of 2007:

Its source is ozone. Atmospheric scientist Richard Keen of the University of Colorado explains: "During a lunar eclipse, most of the light illuminating the moon passes through the stratosphere where it is reddened by scattering. However, light passing through the upper stratosphere penetrates the ozone layer, which absorbs red light and actually makes the passing light ray bluer." This can be seen, he says, as a soft blue fringe around the red core of Earth's shadow.

To catch the turquoise on Sept. 27-28, he advises, "look during the first and last minutes of totality. The turquoise rim is best seen in binoculars or a small telescope."

Realtime Eclipse Photo Gallery

FAST-GROWING SUNSPOT: With few interruptions, solar activity has been very low for weeks. Fast-growing sunspot AR2422 (circled below) could break the quiet. This two-day movie from the Solar Dynamics Observatory shows the sunspot quadrupling in size during the past 48 hours:

The sunspot is big; of greater importance is its magnetic topology. AR2422 has developed an unstable 'beta-gamma' magnetic field that harbors energy for strong M-class solar flares. Because the sunspot is directly facing Earth, any such eruptions will be geoeffective, producing low-frequency radio blackouts and other effects. NOAA forecasters estimate a 35% chance of an M-flare on Sept. 26th. Solar flare alerts: text or voice

Realtime Space Weather Photo Gallery

SPACE CORN FAILS TO APPETIZE: Regular readers of know that we have been flying simple life forms to the edge of space onboard helium balloons to test their response to space weather. Some fare better than others. Yeast, for instance, is incredibly tough. The microbes easily survive temperatures as low as -60 C and cosmic ray dose rates 100x Earth-normal. Corn, on the other hand, appears to be more fragile. In the spring of 2015, the students of Earth to Sky Calculus launched seed packets of corn and other vegetables to the stratosphere during geomagnetic storms. Bruce Binion bought some of these seeds as a gift for his father, a veteran farmer, who planted them alongside regular corn as an experiment. Here are the results:

"I must say this experience has been quite fascinating," reports Binion. "Compared to regular corn, the 'space corn' stalks were quite short, tasseled out quite early, and the ears were stunted. As can be seen in the picture, above, Dad has a normal, good-eating ear from the same garden area shown for reference beside a couple of ears grown from your space seeds."

In summary, cosmic rays do not seem to agree with corn. Sorry, astronauts!

Realtime Aurora Photo Gallery

Realtime Sprite Photo Gallery

  Cosmic Rays

Once a week, and sometimes more, and the students of Earth to Sky Calculus fly a "space weather balloon" equipped with radiation sensors to the stratosphere. The purpose is to monitor cosmic rays. Cosmic rays are a form of space weather that affect us in surpisingly everyday ways. Cosmic rays alter the chemistry of the upper atmosphere, seed clouds, spark exotic forms of lightning, and penetrate commercial airplanes. This last point is of special interest to the traveling public. 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. From now on we will be present the results of our regular weekly balloon flights in this "Cosmic Rays" section of our web site. Here is the radiation profile from our Sept. 23rd flight:

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. In the plot, dose rates are given in microRads per hour (uRads/hr). According to the Sept.23rd measurements, a plane flying at 45,000 feet is exposed to 278 uRads/hr. At that rate, a passenger would absorb about one dental X-ray's worth of radiation in 5 hours.

Stay tuned for improvements to this section in the days and weeks ahead as we develop a glossary and better plain language strategies for communicating this information.

Situation Report -- Sept. 26, 2015 Pfotzer Maximum
Cosmic ray levels are high. The trend is flat. Cosmic ray levels have increased +0% in the past month.
Sept.6: 414 uRad/hr
Sept. 12: 409 uRad/hr
Sept.23: 412 uRad/hr
Sept.25: 416 uRad/hr
  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

On Sep. 26, 2015, the network reported 11 fireballs.
(11 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 September 26, 2015 there were 1611 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2015 SE
Sep 20
4.2 LD
23 m
2015 SK7
Sep 22
0.07 LD
8 m
2015 SU
Sep 23
14.8 LD
36 m
2015 SV6
Sep 25
2.3 LD
13 m
2015 RU36
Sep 26
14.7 LD
39 m
2015 ST6
Sep 29
10.3 LD
58 m
2015 SZ2
Sep 30
1.3 LD
37 m
2015 RF36
Sep 30
14.6 LD
102 m
2015 SO2
Sep 30
14.3 LD
71 m
2000 SM10
Oct 2
11.7 LD
65 m
2015 SR
Oct 3
14.7 LD
54 m
2000 FL10
Oct 10
65.7 LD
1.9 km
2011 QD48
Oct 17
67.5 LD
1.0 km
2014 UR
Oct 18
3.8 LD
21 m
2011 SE97
Oct 18
11.9 LD
50 m
2001 UY4
Oct 21
58.2 LD
1.0 km
2005 UL5
Nov 20
5.9 LD
390 m
2003 EB50
Nov 29
48.8 LD
2.2 km
2007 BG29
Dec 1
54.1 LD
1.1 km
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.
  Essential web links
NOAA Space Weather Prediction Center
  The official U.S. government space weather bureau
Atmospheric Optics
  The first place to look for information about sundogs, pillars, rainbows and related phenomena.
Solar Dynamics Observatory
  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
Solar and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
Daily Sunspot Summaries
  from the NOAA Space Environment Center
  the underlying science of space weather
Columbia Northern High School
  Web-based high school science course with free enrollment
  more links...
©2015 All rights reserved. This site is penned daily by Dr. Tony Phillips.
©2019 All rights reserved.