You are viewing the page for Sep. 15, 2015
  Select another date:
<<back forward>>
SpaceWeather.com -- 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: 479.0 km/sec
density: 3.1 protons/cm3
explanation | more data
Updated: Today at 2350 UT
X-ray Solar Flares
6-hr max: B9
2213 UT Sep15
24-hr: C1
0519 UT Sep15
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 15 Sep 15
Sunspot AR2415 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. Credit: SDO/HMI

Sunspot number: 52
What is the sunspot number?
Updated 15 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 15 Sep 2015


The Radio Sun
10.7 cm flux: 97 sfu
explanation | more data
Updated 15 Sep 2015

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 4
unsettled
explanation | more data
Interplanetary Mag. Field
Btotal: 5.4 nT
Bz: 0.3 nT south
explanation | more data
Updated: Today at 2350 UT
Coronal Holes: 15 Sep 15

Solar wind flowing from this broad northern coronal hole should reach Earth on Sept. 15-16. 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
SPACE WEATHER
NOAA Forecasts
Updated at: 2015 Sep 15 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
05 %
01 %
CLASS X
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 Sep 15 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
30 %
20 %
MINOR
15 %
05 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
20 %
MINOR
25 %
30 %
SEVERE
40 %
25 %
 
Tuesday, Sep. 15, 2015
What's up in space
 

Learn to photograph Northern Lights like a pro. Sign up for Peter Rosen's Aurora Photo Courses in Abisko National Park, winner of the TripAdvisor Certificate of Excellence Award 2015.

 
Lapland tours

ALMOST-QUIET SUN: An uptick in solar activity is underway as sunspot AR2415 begins to crackle with minor C-class solar flares. The sunspot has an unstable 'beta-gamma' magnetic field that harbors energy for even stronger flares. However, the next strong flare will be the first strong flare in more than a month. The odds favor a quick return to quiet conditions. Solar flare alerts: text or voice

SUNDIVING COMET: A comet is diving into the sun today. It appeared just hours ago in images from the Solar and Heliospheric Observatory (SOHO):

The comet is too close to the sun to see with the unaided eye. The only reason SOHO can see it is because the spacecraft can block the glare of the sun with an opaque disk--i.e., a coronagraph.

Sundiving comets are more common than you might think. SOHO has found more than 3000 of them. Most are members of the Kreutz family. Kreutz sungrazers are fragments from the breakup of a single giant comet many centuries ago. They get their name from 19th century German astronomer Heinrich Kreutz, who studied them in detail. Kreutz fragments pass by the sun and disintegrate almost every day. Most, measuring less than a few meters across, are too small to see, but occasionally a bigger fragment like this one attracts attention.

The comet is vaporizing furiously and is not expected to survive much longer. Monitor the SOHO realtime images page for developments.

Realtime Space Weather Photo Gallery

SOLAR WIND SPARKS AURORAS: Sometimes, the trick to seeing Northern Lights isn't a great space weather forecast. It's knowing where to find a break in the clouds. "Last night (Sept. 15th), the whole state of Alaska was clouded over," reports Marketa S Murray, "but we know about a few spots between the mountains where sometimes it is clear even when the rest of Alaska is overcast." She raced to one of those spots, and this is what she saw:

The display was caused by a stream of solar wind, which is buffeting Earth's magnetic field this week. It is just the latest episode in a month-long run of great auroras around the Arctic Circle.

One reason for the recent spate of auroras is the coming change of seasons. For reasons that are not fully understood, auroras love equinoxes. At this time of year even gentle gusts of solar wind can spark a nice display of Northern or Southern Lights.

NOAA forecasters estimate a 55% chance of more geomagnetic storms and auroras on Sept. 15-16 as the solar wind continues to blow. Aurora alerts: text or voice

Realtime Aurora Photo Gallery

DOUBLE ECLIPSE OF THE SUN: On Sept. 13th, the sun was eclipsed--twice! No one on Earth has ever seen anything like it. Indeed, it was only visible from Earth orbit. NASA's Solar Dynamics Observatory (SDO) recorded the event:

The double eclipse began around 06:30 UT when Earth passed directly between the sun and SDO. The observatory watched as the body of our planet moved slowly across the face of the sun, producing a near black-out. When the Earth finally moved aside about an hour later, another eclipse was in progress. This time, the Moon was in the way. A movie from the SDO science team explains the crazy-perfect alignment required for such a view. Update: This picture shows the Moon and the Earth in front of the sun at the same time.

(In the snaphots above, note how the edge of the Earth looks so much fuzzier than the edge of the Moon. That's because our planet has a thick atmosphere and the Moon does not.)

Meanwhile on Earth, an ordinary partial eclipse was visible. People in South Africa and parts of Antarctica saw the Moon pass in front of the sun, off-center, producing crescent-shaped shadows and strange sunrises. Check the realtime photo gallery for their images.

Realtime Space Weather Photo Gallery


Realtime Sprite Photo Gallery


Realtime NLC Photo Gallery

  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 Sep. 15, 2015, the network reported 30 fireballs.
(28 sporadics, 2 September epsilon Perseids)

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 15, 2015 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Size
2015 RC
Sep 8
10.5 LD
60 m
2015 RW35
Sep 13
2.1 LD
6 m
2014 KS76
Sep 14
8.7 LD
22 m
2004 TR12
Sep 15
58.8 LD
1.0 km
2015 RU36
Sep 26
14.7 LD
33 m
2015 RF36
Sep 30
14.6 LD
87 m
2000 SM10
Oct 2
11.7 LD
65 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.
STEREO
  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
Heliophysics
  the underlying science of space weather
Columbia Northern High School
  Web-based high school science course with free enrollment
Aspendell California
   
  more links...
©2015 Spaceweather.com. All rights reserved. This site is penned daily by Dr. Tony Phillips.
©2019 Spaceweather.com. All rights reserved.