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Solar wind
speed: 364.5 km/sec
density: 8.8 protons/cm3
explanation | more data
Updated: Today at 2348 UT
X-ray Solar Flares
6-hr max: C1
2158 UT Oct16
24-hr: M1
0616 UT Oct16
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 16 Oct 15
Sunspot AR2434 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. Credit: SDO/HMI

Sunspot number: 49
What is the sunspot number?
Updated 16 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 16 Oct 2015

The Radio Sun
10.7 cm flux: 107 sfu
explanation | more data
Updated 16 Oct 2015

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 3
explanation | more data
Interplanetary Mag. Field
Btotal: 3.9 nT
Bz: 3.8 nT south
explanation | more data
Updated: Today at 2348 UT
Coronal Holes: 16 Oct 15

Earth is inside a stream of solar wind flowing from this sprawling northern coronal hole. 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 16 2200 UTC
0-24 hr
24-48 hr
55 %
55 %
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 Oct 16 2200 UTC
0-24 hr
24-48 hr
15 %
10 %
05 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
20 %
25 %
20 %
20 %
15 %
Friday, Oct. 16, 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

CHANCE OF STORMS: NOAA forecasters estimate a 50% chance of polar geomagnetic storms on Oct. 16th as Earth dips in and out of a solar wind stream flowing from a gigantic coronal hole on the sun. Last night, the action of this stream produced colorful deep-sky auroras over New Zealand: must-see! Aurora alerts: text or voice

DID RADIATION KILL THE MARTIAN? (Spoiler alert: Stop reading now if you haven't yet seen The Martian.)

The #1 movie in theatres right now is The Martian, a film adaptation of Andy Weir's eponymous book. It tells the heart-pounding story of fictional astronaut Mark Watney, who is stranded on Mars and ultimately rescued by the crewmates who had inadvertently left him behind. To survive long enough to be rescued, Watney has to "science the hell out of" a very tricky situation: he grows food in alien soil, extracts water from rocket fuel, dodges Martian dust storms, and sends signals to NASA using an old Mars rover that had been buried in red sand for some 30 years.

It's a thrilling adventure told with considerable accuracy—except, perhaps, for one thing. "While Andy Weir does a good job of representing the risks faced by Mark Watney stranded on Mars, he is silent on the threat of radiation, not just to Mark but particularly to the crew of the Hermes as they execute a daring rescue mission that more than doubles their time in deep space," says Dr. Ron Turner, Distinguished Analyst at ANSER, a public-service research institute in Virginia.

Space radiation comes from two main sources: solar storms and galactic cosmic rays. Solar storms are intense, short-lived, and infrequent. Fortunately for Mark, there weren't any during his mission. He dodged that bullet. However, he and his crewmates could not have avoided cosmic rays. These are high-energy particles that arise from supernovas, colliding neutron stars, and other violent events happening all the time in the Milky Way. They are ever-present, 24/7, and there is no way to avoid them. So far, NASA has developed no effective shield against these sub-atomic cannon balls from deep space. "Doubling a nominal spacecraft shielding thickness only reduces the GCR [galactic cosmic rays] exposure by a few percent," notes Turner.

In the movie, Watney is actually safer than the crew of the Hermes. Turner explains: "The radiation exposure is significantly less on the surface of Mars. For one thing, the planet beneath your feet reduces your exposure by half. The atmosphere, while thin, further reduces the dose. The dose rate on Mars, while high, is only about 1/3rd of that on the Hermes."

The biggest threat from cosmic radiation exposure is the possibility of dying from radiation-induced cancer sometime after a safe return to Earth. NASA's radiation limits today are set to limit this life-shortening risk to less than three percent. Taking into account many factors, such as the phase of the solar cycle and the number of days the crew spent in deep space and on the surface of Mars, Turner has calculated the total dose of cosmic rays absorbed by Watney (41 cSv) and the crew (72 cSv). "cSV" is a centi-Seivert, a unit of radiation commonly used in discussion of human dose rates.

There is considerable uncertainty in how these doses translate into an increased risk of cancer. Turner estimates the added risk to Watney as somewhere between 0.25% and 3.25%. For members of the crew, the added risk ranges from 0.48% to 7.6%. The high end of these ranges are well outside NASA safety limits. The crew especially could be facing medical problems after their homecoming.

Post-flight cancer is not the only problem, however. "There is some additional concern that sustained radiation exposure could lead to other problems that manifest during the mission, instead of years afterward. Possible examples include heart disease, reduced immune system effectiveness, and neurological effects mimicking the symptoms of Alzheimer disease."

As far as we can tell, none of these things happened to the crew of the Hermes. It's just as well. They had enough trouble without cosmic rays. For the complete details of Turner's analysis CLICK HERE (pdf).

AROUND THE BEND: Get ready for something new. An active sunspot may have announced itself just hours ago by hurling a massive plume of plasma over the sun's southeastern limb. NASA's Solar Dynamics Observatory took this picture on Oct. 16th at 1300 UT:

It is too soon to say whether a CME is emerging from the blast site. Coronagraph data from SOHO are not yet available. However, even if the explosion did produce a CME, it is not heading for Earth. The instigating sunspot is still on the farside of the sun, more than 90o off the sun-Earth line.

What's coming around the bend? Readers with solar telescopes are encouraged to monitor developments. Solar flare alerts: text or voice

Realtime Space Weather Photo Gallery

Realtime Aurora Photo Gallery

Realtime Eclipse Photo Gallery

Realtime Sprite Photo Gallery

  Cosmic Rays in the Atmosphere
Situation Report -- Oct. 14, 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. 16, 2015, the network reported 27 fireballs.
(17 sporadics, 4 Southern Taurids, 3 October Ursae Majorids, 2 October delta Aurigids, 1 epsilon Geminid)

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 16, 2015 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2015 TB25
Oct 11
9.5 LD
54 m
2015 TK21
Oct 12
4.8 LD
23 m
2015 TG24
Oct 12
4 LD
20 m
2015 TA238
Oct 13
5.8 LD
25 m
2015 TC25
Oct 13
0.3 LD
6 m
2015 TC179
Oct 14
12.3 LD
26 m
2015 TG144
Oct 16
13.3 LD
33 m
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
2015 TD144
Oct 20
11.7 LD
130 m
2001 UY4
Oct 21
58.2 LD
1.0 km
2015 TZ143
Oct 22
4.2 LD
26 m
2015 TL238
Oct 27
13.3 LD
50 m
2015 TB145
Oct 31
1.3 LD
470 m
2015 TD179
Nov 4
10.6 LD
57 m
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.
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