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Captions and High-resolution Images:
Item 1 caption:
This is a picture of the large sunspots associated with Active Region 10484 taken October 24, 2003 with SOHO's Michelson Doppler Imager (MDI) instrument. The dark blotches in the middle of the image are the sunspots, which are cool, relatively dark regions on the Sun's visible surface. This sunspot group could cover 10 times the entire surface of the Earth. Active Region 10484 was associated with several powerful solar flares, including one X-class event (the most powerful category, capable of releasing the energy of a billion one-megaton nuclear bombs).
Credit: NASA and the European Space Agency
Item 2
(3.8 MEG TIF image)
Item 2 caption:
This is a picture of the large sunspots associated with Active Region 10486 (bottom group of dark blotches) taken October 28, 2003 with SOHO's Michelson Doppler Imager (MDI) instrument. This sunspot group was even larger than the sunspots associated with Active Region 10484 (see Item 1 above). Region 10486 was monstrous and produced the largest flare ever recorded in X-rays on November 4, 2003 before rotating behind the edge of the Sun.
Credit: NASA and the European Space Agency
Item 3
(5.3 MEG TIF image)
Item 3 caption:
This picture is a false-color image of an X-17 solar flare on October 28, 2003, made with SOHO's Extreme ultraviolet Imaging Telescope (EIT). X-class flares are most powerful category, capable of releasing the energy of a billion one-megaton nuclear bombs. The flare is the large, white area in the bottom half of the solar disk (the horizontal lines resulted when the flare's intense light saturated the EIT instrument). The flare came from Active Region 10486, as part of a "one-two punch" of flares and Coronal Mass Ejections (CMEs) within a day of each other.
Credit: NASA and the European Space Agency
Item 4
(9.7 MEG TIF image)
Item 4 caption:
This image sequence shows a Coronal Mass Ejection (CME) associated with the October 28 X-17 solar flare. The images are false-color, taken with SOHO's Large Angle and Spectrometric Coronagraph (LASCO) instrument. The disk in the center of the image blocks the Sun's direct light so much fainter features in the solar atmosphere (corona) can be seen. The white circle on the disk represents the apparent size of the Sun in the image. The CME is the white, wispy cloud surrounding the LASCO disk. The CME expands in the field of view as it approaches the SOHO spacecraft because it was directed toward Earth, and the SOHO spacecraft is positioned directly between the Sun and the Earth. The white spots in the third and fourth images are the impacts of high-speed particles on the LASCO instrument. These electrically charged particles were accelerated to high speeds by the solar flare and CME shocks; this radiation can sometimes disrupt spacecraft electronics.
Credit: NASA and the European Space Agency
Item 5
(7.1 MEG TIF image)
Item 5 caption:
This is a montage of SOHO imagery of the October 28, 2003 flare and CME activity. See the captions with Items 2 through 4 for a complete description. Top Left: Sunspots with the MDI instrument. Top right: X-17 flare with the EIT instrument. Bottom right: CME with the LASCO C3 instrument. Bottom left: CME closeup with the LASCO C2 instrument.
Credit: NASA and the European Space Agency
Item 6
(891 KB GIF image)
Item 6 caption:
This picture is a false-color image of the X-28 flare on November 4, 2003 taken with SOHO's Extreme ultraviolet Imaging Telescope (EIT). X-class flares are most powerful category, capable of releasing the energy of a billion one-megaton nuclear bombs. The flare is the white area near the bottom right of the image (the horizontal lines resulted when the flare's intense light saturated the EIT instrument). The flare came from Active Region 10486, and is the largest flare ever recorded in X-rays.
Credit: NASA and the European Space Agency
Item 7
(755 KB GIF image)
Item 7 caption:
This is a picture of the Coronal Mass Ejection associated with the November 4, 2003 X-28 flare from Active Region 10486. This CME was the fastest yet observed, and was blasted from the Sun at 2,700 kilometers per second (about six million miles per hour). The picture was taken with SOHO's Large Angle and Spectrometric Coronagraph (LASCO) C2 instrument, which provides a close-up view of CMEs. The disk in the center of the image blocks the Sun's direct light so much fainter features in the solar atmosphere (corona) can be seen. The white circle on the disk represents the apparent size of the Sun in the image. The CME is the large white area at the lower right of the LASCO C2 disk.
Credit: NASA and the European Space Agency
Item 8
(905 KB GIF image)
Item 8 caption:
This is a picture of the Coronal Mass Ejection associated with the November 4, 2003 X-28 flare from Active Region 10486. This CME was the fastest yet observed, and was blasted from the Sun at 2,700 kilometers per second (about six million miles per hour). The false-color picture was taken with SOHO's Large Angle and Spectrometric Coronagraph (LASCO) C3 instrument, which provides a wide-angle view of CMEs. The disk in the center of the image blocks the Sun's direct light so much fainter features in the solar atmosphere (corona) can be seen. The white circle on the disk represents the apparent size of the Sun in the image. The CME is the faint, blue-white area at the lower right of the LASCO C2 disk. NOTE: The bright spot moving from right to left in the movie is the planet Mercury. The planet is bright enough to saturate the LASCO detector, producing horizontal lines around the spot.
Credit: NASA and the European Space Agency
Item 8a
(1.9 MEG TIF image)
Caption for Item 8a:
On November 4, 2003, the Sun produced the fastest coronal mass ejection (CME) yet observed out of active region 10486 located near the southwest limb of the Sun (bottom right in image and movie). The CME was expelled with a speed of approximately 2,700 kilometers per second (1,678 miles/sec). At the time of the launch of this CME, there was another ejection in progress from the same region. The previous ejection started about 7 hours earlier with a speed of about 1,000 km/sec (621 miles/sec). The fastest CME overtook the previous one within 2 hours and produced a spectacular radio radiation detected by the Wind, Ulysses and Cassini spacecraft. The movie shows the radio emission and the two interacting CMEs as observed by the SOHO spacecraft.
Credit: NASA and the European Space Agency
Item 9
(4.2 MEG TIF image)
Item 9 caption:
This image series shows Active Region10484 (renamed 10501) as it rotates with the Sun into view again. Large, bright loops can be seen on the lower left side of the Sun, revealing the presence of twisted magnetic fields that comprised this region. Active Region 10501 ejected a CME that caused the largest geomagnetic storm of the current cycle (solar cycle 23). These false color images were made with SOHO's Extreme ultraviolet Imaging Telescope (EIT). The different colors represent different frequencies of extreme ultraviolet light, which is emitted by the hot, electrically charged solar gas.
Credit: NASA and the European Space Agency
Items 10 - 12 caption:
This series of images shows an aurora over the Antarctic region November 20, 2003, taken by the Imager for Magnetopause to Aurora Global Exploration (IMAGE) spacecraft. The aurora is the colored band (false color) surrounding the Antarctic continent in the images. The image was taken with the Far Ultraviolet Imager on board IMAGE, which makes pictures of the ultraviolet light emitted during an aurora. Ultraviolet light is invisible to the human eye, but detectable by special instruments, which use a computer program to generate the false-color images.
This aurora was part of the largest geomagnetic storm of the current solar cycle (cycle 23), and resulted from an Earth-directed Coronal Mass Ejection (CME) from active region 10501. A spectacular aurora formed over the Antarctic regions November 20 beginning at 8:00 UT (3:00 a.m. Eastern Time). The impact of the massive blast of CME plasma (electrified gas) caused our planet's magnetic field to ring like a bell, forming this special kind of aurora called a "pressure pulse" aurora.
The aurora, also known as the Northern and Southern Lights, form when solar particles and magnetic fields pump energy into the Earth's magnetic field, accelerating electrically charged particles trapped within. The high-speed particles crash into Earth's upper atmosphere (ionosphere) over the polar regions, causing the atmosphere to emit a ghostly, multicolored glow.
The strongest aurora are formed when the magnetic field carried by a cloud of plasma from the Sun has a direction oriented opposite to the direction of the Earth's magnetic field. The Earth's field points northward, and, in this case, the cloud's field was aligned strongly southward, producing an intense aurora.
Credit: NASA
Item 13 caption:
This is a movie of the November 20 aurora made by the Visible Imaging System on board the Polar spacecraft. Ultraviolet light from the aurora is seen in false color as a green ring around the Antarctic continent. For more details, see the caption for Images 10 through 12.
Credit: NASA
Item 14
(1.9 MEG TIF image)
Item 14 caption:
This image and movie shows Coronal Mass Ejections (CMEs) on November 18, 2003 associated with active region 10501. One of these CMEs caused the largest geomagnetic storm of the current solar cycle (cycle 23).
The images are false-color, taken with SOHO's Large Angle and Spectrometric Coronagraph (LASCO) instrument. The disk in the center of the image blocks the Sun's direct light so much fainter features in the solar atmosphere (corona) can be seen. The white circle on the disk represents the apparent size of the Sun in the image. The CME is the white, wispy cloud emanating from the bottom of LASCO disk.
(Two CMEs are shown in the movie, first, a faint CME from the bottom right of the LASCO disk and second, a brighter CME from the bottom left. The CME that caused the geomagnetic storm is actually the first, fainter one. Refer to the difference movie to get a better view of this CME. The difference movie highlights detail that changes from frame to frame in a movie, so faint structures can be seen.)
Credit: NASA and the European Space Agency
Item 15 caption:
This is a model curve showing the expected Sun-to-Earth travel times of CME-driven shocks. The travel times of a set of extreme events is shown by the symbols. Squares: SOHO CMEs (left square 7/14/00 event, middle square 10/29/03 event, right square 10/28/03 event). Diamonds: Historical events with known transit times (from Cliver et al, Journal of Geophysical Research, 1990).
Credit: NASA/ESA/Gopalswamy
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