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Glossary

 

CME
Large amounts of plasma (consisting of mostly electrons and protons) ejected from the sun.
Gamma-Ray Bursts
Short bursts of gamma-rays (very high frequency electromagentic radiation) with very energetic explosions. These bursts can last from a few milliseconds to a few about an hour.
Geomagnetic Storms
A disturbance in the Earth's magnetosphere caused by changes in space weather such as solar erutptions.
Heliosphere
The region around the sun that is filled with the Sun's gases, solar winds, and magentic fields.
IMF
The magnetic field produced by the Sun that is carried through by solar winds.
Ionosphere
The uppermost part of the atmosphere. It also forms the inner surface of the magnetosphere and is reponsible for radio communication between distant places on Earth.
Lagrangian Point
Equilibrium points in space where the gravitational pull by a massive body is equal to that of another body.
Magnetosphere
Forms when a stream of charged particles, such as a solar wind, interacts with the magnetic field of a planet.
Photosphere
The surface of the sun that you see.
Solar Eruptions
These are sudden intense bursts of energy in the sun. They may develop in a few minutes and last for several hours.
Solar Wind
A constant stream pf charged particles, such as electrons and protons, that are continuously ejected from the upper atmosphere of the Sun.
Suprathermal Ions
Ions, charged particles, that have more energy than similar particles of the same type.

Can’t find the word here? Check out our full glossary

Archive 2002

Nov 27, 2002

A solar Coronal Mass Ejection (CME) swept past Earth at approximately 21:50 UT (4:50 p.m. EST) on Tuesday, Nov. 26th, and triggered an ongoing geomagnetic storm. When the CME arrived, the interplanetary magnetic field near Earth tilted south--a condition that favors Northern Lights. Sky watchers in northern Europe, Canada and northern US states (where night is falling as the geomagnetic storm intensifies) should therefore be alert for auroras. (spaceweather.com)

Oct 26, 2002

Solar wind gusts have triggered auroras off and on since Oct. 23rd. There could be even more geomagnetic activity this weekend if a Coronal Mass Ejection (CME) sweeps past our planet as expected. The CME billowed away from the Sun on Oct. 25th not long after a spectacular prominence erupted--the movie on spaceweather.com is a must-see. Sky watchers should be alert for Northern Lights after nightfall on Saturday and Sunday. (spaceweather.com)

Oct 4, 2002

The interplanetary magnetic field near Earth turned south again on Thursday, Oct. 3rd, and re-energized the current spate of geomagnetic activity. Sky watchers--particularly those in northern Europe, Canada, New Zealand, southern Australia, and across the northern tier of US states--should remain alert for auroras. The hours around local midnight are usually best for spotting Northern (and Southern) Lights. (spaceweather.com)

Oct 2, 2002

A solar wind stream buffeted Earth's magnetic field early Tuesday, Oct. 1st, and triggered a strong geomagnetic storm. Sky watchers spotted colorful auroras all the way from the Bering Sea to Arizona. Although the storm has subsided, Earth remains inside a gusty solar wind stream. More auroras are therefore possible on Wednesday, Oct. 2nd. Visit spaceweather.com for updates and for pictures of the Oct. 1st Northern Lights. (spaceweather.com)

July 19, 2002

Another Coronal Mass Ejection is heading for Earth. It was hurled into space Thursday, July 18th, by an explosion near the huge sunspot 30. The expanding cloud could trigger geomagnetic activity when it sweeps past our planet. Sky watchers--especially those at high latitudes--should be alert for possible auroras after nightfall on Friday and Saturday. (spaceweather.com)

July 8, 2002

A group of astronauts will never forget the day they flew right through a cloud of auroras while onboard the space shuttle Atlantis. For the full story, click here. (Science@NASA)

May 23, 2002

A geomagnetic storm is underway on Thursday, May 23rd, after a Coronal Mass Ejection struck Earth's magnetic field earlier and with greater energy than anticipated. Sky watchers, especially those at high latitudes, should be alert for auroras after local nightfall on Thursday. Observers in, e.g., northern Europe, Canada and across the northern tier of US states are favored, but mid-latitude observers might spot something, too, if the storm continues and intensifies. (spaceweather.com)

May 11, 2002

An unexpected interplanetary shock wave swept past Earth at 1000 UT on May 11th and triggered a moderate geomagnetic storm. High-latitude sky watchers -- i.e., those in northern Europe, Canada and across the northern tier of US states -- should be alert for auroras after local nightfall on Saturday. Although the shock wave was not a particularly strong one, it stimulated a geomagnetic storm because the interplanetary magnetic field near Earth is pointing south -- a condition that weakens our planet's magnetic defenses against solar wind disturbances.

April 21, 2001

A pair of Coronal Mass Ejections swept past Earth last week and ignited several days of geomagnetic activity. Although the most intense Northern Lights were concentrated above high-latitudes, photographers recorded auroras as far south as Arizona and Southern California in the United States. (spaceweather.com)

April 19 - 20, 2002

A Coronal Mass Ejection swept past Earth on Friday morning (April 19) and triggered a moderate geomagnetic storm. Instead of waning with the passage of time, however, the storm has intensified. Sky watchers in Canada and across the northern tier of US states report seeing auroras on Friday evening (April 19). Northern skies will continue to glow through Saturday morning (April 20) if geomagnetic activity persists at current levels. High-latitude sky watchers should remain alert for naked-eye auroras, while mid-latitude observers might be able to record fainter auroras on film. Sky watchers in southern Australia and New Zealand might also spot Southern Lights. (spaceweather.com)

April 17, 2002

A Coronal Mass Ejection swept past Earth this morning and triggered a moderate geomagnetic storm. The disturbance began at 1100UT on April 17th was still happening 12 hours later when this alert was issued. High-latitude sky watchers -- i.e., those in northern Europe, Canada and the northern tier of US states -- should remain alert for auroras after sunset on Wednesday. Later this week, wisted magnetic fields above sunspot 9906 erupted and hurled a lopsided Coronal Mass Ejection toward Earth on April 17th. The expanding cloud could ignite Northern Lights when it sweeps past our planet on April 19th or 20th. (spaceweather.com)

April 16, 2002

On Monday, April 15th (0400 UT), a full-halo Coronal Mass Ejection billowed away from the Sun. The expanding cloud is heading toward Earth and could ignite Northern Lights (most likely at high latitudes but possibly at mid-latitudes as well) when it sweeps past our planet on April 17th or 18th. (spaceweather.com)

March 17, 2002

An explosion on the Sun hurled a Coronal Mass Ejection toward Earth late on Friday, March 15th. The CME could sweep past Earth as early as Sunday night and trigger auroras. High-latitude sky watchers -- e.g., those in northern Europe, Canada, and the northern tier of US states-- should remain alert for Northern Lights after sunset on Sunday and perhaps again on Monday. It's possible that auroras might extend to lower latitudes as well; the crescent Moon will not overwhelm faint auroras. No matter where you live, the best times to watch will be during the hours around local midnight. (spaceweather.com)

Last updated 01/25/2010 © UC Regents