AURORAS INVADE THE USA:

AURORAS INVADE THE USA: Earth's magnetic field is still reverberating from a CME strike on March 10th. During the past 24 hours, Northern Lights have descended as far south as Wisconsin, Minnesota, and Michigan in the United States. "It was nice to see the aurora borealis again after so many years of low activity," says Jerry Zhu, who sends this picture from Madison, WI:

Solar wind conditions favor more geomagnetic storming in the hours ahead. Sky watchers--even those in the continental United States--should remain alert forauroras.
more USA images: from Shawn Malone of Marquette, Michigan; from Andrew Krueger of Duluth, Minnesota; from Dennis Zerwas Jr near Cambridge, Minnesota;from Bill Doms of Santiago, Minnesota; from Bob Conzemius of Grand Rapids, Minnesota; from Kristine Deppe near Cook, Minnesota; from Scott Anttila of Ishpeming, Michigan; from Dan Miller near Duluth, Minnesota;.

UPDATED: March 2011 Aurora Photo Gallery
[previous Marches: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002]

X-FLARE: March 9th ended with a powerful solar flare. Earth-orbiting satellites detected an X1.5-class explosion from behemoth sunspot 1166 around 2323 UT. A movie from NASA's Solar Dynamics Observatory shows a bright flash of UV radiation plus some material being hurled away from the blast site:

Movie formats: 4 MB gif, 1.2 MB iPad, 0.3 MB iPhone

UPDATE (March 10 @ 1800 UT): Newly-arriving coronagraph data from the Solar and Heliospheric Observatory show no bright CME emerging from this eruption. Some material was surely hurled in our direction, but probably not enough for significant Earth-effects.

After four years without any X-flares, the sun has produced two of the powerful blasts in less than one month: Feb. 15th and March 9th. This continues the recent trend of increasing solar activity, and shows that Solar Cycle 24 is heating up. NOAA forecasters estimate a 5% chance of more X-flares during the next 24 hours.

SOLAR FLARE ALERTS: Would you like a call when the next X-flare erupts? Sign up for Spaceweather PHONE.

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 March 11, 2011 there were 1204 potentially hazardous asteroids.

Recent & Upcoming Earth-asteroid encounters:

Asteroid	Date(UT)	Miss Distance	Mag.	Size
2011 EC	Mar 6	9.2 LD	--	34 m
2011 EO11	Mar 6	1.8 LD	--	15 m
2011 EY11	Mar 7	0.3 LD	--	9 m
2011 EM40	Mar 7	0.7 LD	--	12 m
2011 EL40	Mar 8	3.4 LD	--	23 m
2011 EC12	Mar 8	3.3 LD	--	30 m
2000 PN9	Mar 10	45.5 LD	--	2.6 km
2011 EU20	Mar 11	1.6 LD	--	16 m
2011 BE38	Apr 10	48 LD	--	1.0 km
2002 DB4	Apr 15	62.5 LD	--	2.2 km
2008 UC202	Apr 27	8.9 LD	--	10 m
2009 UK20	May 2	8.6 LD	--	23 m
2008 FU6	May 5	75.5 LD	--	1.2 km
2003 YT1	May 5	65.3 LD	--	2.5 km
2002 JC	Jun 1	57.5 LD	--	1.6 km
2009 BD	Jun 2	0.9 LD	--	9 m
2002 JB9	Jun 11	71.5 LD	--	3.2 km
2001 VH75	Jun 12	42.2 LD	--	1.1 km
2004 LO2	Jun 15	9.9 LD	--	48 m

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

Conquest Graphics

for out-of-this-world printing and graphics

Science Central