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Solar wind
speed: 440.3 km/sec
density: 4.8 protons/cm3
explanation | more data
Updated: Today at 2347 UT
X-ray Solar Flares
6-hr max: B2
2209 UT Oct05
24-hr: B2
2209 UT Oct05
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 05 Oct 15
The magnetic field of sunspot AR2427 is decaying and no longer poses a threat for strong solar flares. Credit: SDO/HMI

Sunspot number: 18
What is the sunspot number?
Updated 05 Oct 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 05 Oct 2015

The Radio Sun
10.7 cm flux: 97 sfu
explanation | more data
Updated 05 Oct 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= 5
explanation | more data
Interplanetary Mag. Field
Btotal: 4.1 nT
Bz: 3.5 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 05 Oct 15

Solar wind flowing from the indicated coronal hole should reach Earth on Oct 8-9. 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 Oct 05 2200 UTC
0-24 hr
24-48 hr
01 %
01 %
01 %
01 %
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 Oct 05 2200 UTC
0-24 hr
24-48 hr
20 %
25 %
05 %
10 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
15 %
30 %
30 %
25 %
35 %
Monday, Oct. 5, 2015
What's up in space

Marianne's Heaven On Earth Aurora Chaser Tours invites you to join them in their quest to find and photograph the Aurora Borealis. Experience the winter wonderland in the Tromsø Area.

Chase the Light Tours

SUBSIDING CHANCE OF FLARES: There are only a few small sunspots on the solar disk, and none of them poses a threat for strong explosions. NOAA forecasters have lowered the odds of an M-class solar flare today to only 10%. Solar flare alerts: text or voice

NO CME, AURORAS ANYWAY: A CME expected to hit Earth's magnetic field on Oct. 4th did not; it missed. Auroras appeared anyway. "The sky erupted into a multicolour flash of green and purple that will never be forgotten by anyone in our group," reports aurora tour guide Chad Blakley,who send this picture from Abisko, Sweden:

"While the display was likely not caused by the CME, it was a spectacular event, and was well worth the wait,"says Blakley. "Let's hope that the rest of the aurora season is as impressive!"

If the CME didn't make these auroras, what did? Answer: The interplanetary magnetic field (IMF) near Earth tipped south. This opened a crack in our planet's magnetosphere. Solar wind poured in to fuel the display. Aurora alerts: text or voice

Realtime Aurora Photo Gallery

'WATER-BASED LAVA' ON PLUTO'S MOON? Pluto's moon Charon is so large that some astronomers have called Pluto and Charon a "double-planet." Could Charon be just as interesting as Pluto? Images just received from NASA's New Horizons spacecraft suggest that it is. When New Horizons hurtled past the Pluto-Charon system last July, it saw a canyon system stretching more than 1,000 miles across Charon's icy face. Four times as long as the Grand Canyon, and twice as deep in places, the structure marks a titanic geological upheaval in Charon's past:

"It looks like the entire crust of Charon has been split open," says John Spencer, a member of the New Horizons Science Team from the Southwest Research Institute. "With respect to its size relative to Charon, this feature is much like the vast Valles Marineris canyon system on Mars."

The pictures also show plains south of the Charon's canyon with fewer large craters than regions to the north. This means the southern plains are younger. The smoothness of the plains, as well as their grooves and faint ridges, are clear signs of wide-scale resurfacing:

One possibility for the smooth surface is a kind of cold volcanic activity, called cryovolcanism. "The team is discussing the possibility that an internal water ocean could have frozen long ago, and the resulting volume change could have led to Charon cracking open, allowing water-based lavas to reach the surface," says Paul Schenk, a New Horizons team member from the Lunar and Planetary Institute in Houston.  

More images and data are in the offing as New Horizons continues to transmit data, stored on its digital recorders, over the next year. As that happens, "I predict Charon's story will become even more amazing!" says mission Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory. Stay tuned.

Realtime Space Weather Photo Gallery

COSMIC RAYS DURING THE LUNAR ECLIPSE: On the evening of Sept. 27th, and the students of Earth to Sky Calculus conducted a routine flight of their cosmic ray payload to the stratosphere. Routine, that is, except for one thing: the balloon flew at night during a lunar eclipse. One of the goals of the flight was to compare radiation levels at night to those recorded during the day. Here are the data they recorded:

Compare this plot of radiation vs. altitude to a similar plot recorded in broad daylight only a few days earlier. They are almost identical. Radiation levels in the stratosphere matched at the 1% level. Radiation levels at aviation altitudes (where planes fly) agreed within about 3%. Night and day were the same.

This simple experiment highlights something that is already well known to researchers. Cosmic rays in Earth's atmosphere come mainly from deep space. They are accelerated toward Earth by supernovas, colliding neutron stars, and other violent events in the Milky Way. Flying at night is no safeguard against these energetic particles because they are everpresent, coming at us from all directions, day and night.

HEY THANKS (and Happy Birthday): The lunar eclipse flight was sponsored by reader JR Biggs, whose donation of $500 paid for the supplies neccesary to get the balloon off the ground. To say "thank you" for his contribution, we flew a birthday card for his daughter to the edge of space:

Happy Birthday to Autumn! She will be watching a complete video of the flight when she turns 4 on Oct. 10th.

Readers, if you would like to support a research flight and send your birthday card, business logo, or other photo along for the ride, it only costs $500. Contact Dr. Tony Phillips to make arrangements.

Realtime Eclipse Photo Gallery

Realtime Sprite Photo Gallery

  Cosmic Rays in the Atmosphere
Situation Report -- Oct. 3, 2015 Stratospheric 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: 414 uRad/hr
Sept. 12: 409 uRad/hr
Sept. 23: 412 uRad/hr
Sept. 25: 416 uRad/hr
Sept. 27: 413 uRad/hr
These measurements are based on space weather balloon flights, described below.

Introduction: Once a week, and sometimes more often, and the students of Earth to Sky Calculus fly "space weather balloons" to the stratosphere. These balloons are equipped with radiation sensors that detect cosmic rays, a form of space weather important to people on Earth. Cosmic rays can 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 present the results of our regular weekly balloon flights in this section of our web site. Here is the radiation profile from our latest flight:

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 nearly 100x 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 Sept. 27th measurements, a plane flying at 45,000 feet is exposed to 288 uRads/hr. At that rate, a passenger would absorb about one dental X-ray's worth of radiation in 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.

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. Suggestions are welcomed.

  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 Oct. 5, 2015, the network reported 6 fireballs.
(5 sporadics, 1 Southern Taurid)

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 October 5, 2015 there were 1612 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2000 SM10
Oct 2
11.7 LD
65 m
2015 SR
Oct 3
14.7 LD
54 m
2015 SJ17
Oct 3
11.8 LD
14 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
1998 WT24
Dec 11
10.9 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.
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