You are viewing the page for Aug. 27, 2009
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 381.8 km/sec
density: 3.8 protons/cm3
explanation | more data
Updated: Today at 2344 UT
X-ray Solar Flares
6-hr max: A0
2340 UT Aug27
24-hr: A0
2340 UT Aug27
explanation | more data
Updated: Today at: 2340 UT
Daily Sun: 27 Aug 09
The sun is blank--no sunspots. Photo credit: SOHO/MDI
Sunspot number: 0
What is the sunspot number?
Updated 26 Aug 2009

Spotless Days
Current Stretch: 47 days
2009 total: 189 days (79%)
Since 2004: 700 days
Typical Solar Min: 485 days
explanation | more info
Updated 26 Aug 2009

Far side of the Sun:
This holographic image reveals no sunspots on the far side of the sun. Image credit: SOHO/MDI
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 2
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Interplanetary Mag. Field
Btotal: 1.6 nT
Bz: 0.7 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes:
Several holes have opened up in the sun's corona. A solar wind stream flowing from two of them could reach Earth as early as August 28th or 29th. Credit: SOHO Extreme UV Telescope
NOAA Forecasts
Updated at: 2009 Aug 27 2201 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: 2009 Aug 27 2201 UTC
0-24 hr
24-48 hr
15 %
05 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
05 %
01 %
01 %
01 %
01 %
What's up in Space
August 27, 2009

AURORA ALERT: Did you miss the Northern Lights? In July they descended as far south as Nebraska. Next time get a wake-up call: Spaceweather PHONE.


HOAX ALERT: Today is the day of the Mars Hoax. According to a widespread rumor, on August 27th Mars will approach Earth so close that it looms as large as a full Moon in the Thursday-night sky. Don't believe it.

LUNAR OCCULTATION: On Thursday, Aug. 27th, the half Moon will pass directly in front of first-magnitude star Antares. The event is best seen from the Atlantic side of North America. Small telescopes pointed at the Moon will show Antares vanish behind the Moon's dark limb around 4:30 pm EDT, all framed by afternoon blue sky. [time tables]

SOLAR ACTIVITY: In the pits of a century-level solar minimum, the sun is setting new records for quiet. But really, how quiet can a 1027-ton nuclear explosion (a star) ever be? The Solar and Heliospheric Observatory recorded some lively action on August 25th and 26th:

The 42-hour time-lapse movie shows a prominence, a swirling cloud of hydrogen held up unsteadily by solar magnetic fields. Prominences appear to be the one form of solar activity that continues apace even when sunspots are absent. Readers with solar telescopes, for a good show train your optics on the edge of the sun.

more images: from Joe Bartolick of Livermore, California; from Michael Buxton of Ocean Beach, California; from Adrian Guzman of San Jose, CA; from Richard Bailey of Barham, Kent, UK; from Monty Leventhal of Sydney. Australia; from Stephen Ames of Hodgenville, Kentucky; from Pavol Rapavy of Observatory Rimavska Sobota, Slovakia; from Fabio Mariuzza of Biauzzo, Codroipo, Italy

DISAPPEARING MOON: One of the moons shown below is about to disappear. Click on the image to watch it happen:

Efrain Morales Rivera of Aguadilla, Puerto Rico, made the movie on August 19th. It shows Jupiter's giant moon Ganymede casting its shadow across smaller Europa.

"I used a Meade LX200 telescope and a CCD camera to record the event," he says. The camera rolled for two hours, "and I gathered 10 gigabytes of data before Hurricane Bill intervened." The storm was passing by Puerto Rico, and its clouds shut down the observing session.

That's okay, there are more photo-ops to come. Earth is passing through the orbital plane of Jupiter's moons, lining them up for a delightful display of mutual occultations and eclipses in September. Get the full story from Sky & Telescope.

more images: from Jeremy Perez of Flagstaff, Arizona; from Mark A. Brown of Springfield, Virginia; from Rudi Dobesberger of Neuzeug, Austria; from Antonios Pantelidis of Florina, Greece; from Lütfü Çakmak of K.Maras, Turkey

August 2009 Aurora Gallery
[previous Augusts: 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001]

Explore the Sunspot Cycle

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 August 27, 2009 there were 1068 potentially hazardous asteroids.
August 2009 Earth-asteroid encounters:
Miss Distance
2009 MC9
Aug. 7
70.3 LD
1.2 km
2009 OF
Aug. 8
15.4 LD
220 m
2007 RQ17
Aug. 9
8.4 LD
130 m
2000 LC16
Aug. 17
75.6 LD
2.0 km
2006 SV19
Aug. 21
59.2 LD
1.3 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 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 and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
  3D views of the sun from NASA's Solar and Terrestrial Relations Observatory
Daily Sunspot Summaries
  from the NOAA Space Environment Center
Current Solar Images
  from the National Solar Data Analysis Center
Science Central
  more links...
©2008, -- This site is penned daily by Dr. Tony Phillips.
©2019 All rights reserved.