Title:[0410] A gargantuan solar prominence Caption:One of the most spectacular solar prominences ever observed. Imaged in far ultraviolet light by Skylab in December 1973, it spanned 367,000 miles (588,000 km) across the surface of the Sun. Copyright: Credit:A NASA/JPL PHOTO

Title:[1155] A solar flare in hydrogen alpha light Caption:A large and very bright solar flare observed in hydrogen alpha light (wavelength 565 nm) on 9 March 1989. Copyright: Credit:National Optical Astronomy Observatories

Title:[2004] Total eclipse of the Sun in 1970 Caption:The solar corona during the total eclipse of the Sun on 7 March 1970. Copyright: Credit: National Optical Astronomy Observatories

Title:[0562] The visible surface of the Sun Caption:The surface of the Sun, seen in visible light, is called the photosphere. Most of the Sun's radiation is emitted from the photosphere in visible and near-infrared light. Above this layer of opaque gas is the Sun's atmosphere, which is composed of extremely hot gas, is transparent to visible light, and emits radiation primarily in x-ray and ultraviolet wavelengths. This white-light photograph of the Sun taken on 19 February 1982 shows several sunspots including a very unusual spiral sunspot. Copyright:(c) Smithsonian Astrophysical Observatory Credit:Courtesy of National Optical Astronomy Observatories

Title:[1167] The Sun photographed in red hydrogen-alpha light Caption:Full disk photograph of the Sun, taken in red hydrogen-alpha light at the National Solar Observatory, Sacramento Peak, New Mexico. The dark streaks, called filaments, are prominences silhouetted against the bright photosphere. Copyright: Credit:National Optical Astronomy Observatories

Title:[3004] Partially eclipsed Sun prior to total eclipse, 11 July 1991 Caption:The Sun partially eclipsed prior to totality on 11 July 1991. Several large sunspots are visible, and the mountainous terrain along the Moon's limb silhouetted against the disk of the Sun. Copyright:Daniel Good Credit:Daniel Good

Title:[3005] Solar prominence erupting from eclipsed Sun, 11 July 1991 Caption:A huge solar prominence extending about 80,000 miles from the Sun's western limb caught at the moment totality ended during the eclipse of 11 July 1991. Copyright:Dennis di Cicco Credit:Dennis di Cicco

Title:[3006] Diamond ring effect, total solar eclipse 11 July 1991 Caption:The so-called "diamond ring" effect captured at the end of totality during the solar eclipse of 11 July 1991. It happens as the first bead of light shines through the uneven profile of the Moon's limb. Copyright:James Curry Credit:James Curry

Title:[3008] Annular eclipse of the Sun sequence, 24 December 1973 Caption:The five images on this multiple exposure of the annular eclipse of the Sun on 24 December 1973 cover a period of an hour and a half, but the camera was repositioned for each shot. The photograph was taken from Costa Rica where the Sun rose already partially eclipsed. Copyright:Dennis di Cicco Credit:Dennis di Cicco

Title:[3009] Nearly total annular eclipse of the Sun, 30 May 1984 Caption:The annular eclipse of the Sun on 30 May 1984 left only a very thin ring of the Sun visible at mid-eclipse. This image was made using a semicircular neutral-density filter over the eastern (left) half of the Sun. The unfiltered half of the image shows the effect known as "Baily's beads," caused by the Sun shining through valleys on the Moon's limb, as well as prominences and part of the corona. Copyright:Dennis di Cicco Credit:Dennis di Cicco

Title:[3010] Outer solar corona in false color from Skylab Caption: False-color emphasizes the structure of the outer solar corona as seen from Skylab in 1973. From this orbiting space station, the outer corona was monitored continuously for a period of 9 months with a coronagraph that blocked out the light of the Sun's disk. Copyright: Credit:NASA/JPL

Title:[3011] Coronal spikes in false color from Solar Maximum Mission, June 1980 Caption:False-color reveals the density and structure of the solar corona in this image from the orbiting Solar Maximum Mission in 1980. The coronal spike extending from the densest (dark blue) part of the corona could be detected over 1.6 million km (1 million miles). Copyright: Credit:NASA/JPL

Title:[3012] Solar magnetogram of active Sun Caption:This magnetogram taken from Skylab (1973/4) reveals bands of solar activity either side of the Sun's equator. Red and blue areas are regions of strong magnetic field of opposite polarity. Large sunspots often occur in pairs, one of each polarity (north and south). Copyright: Credit:NASA/JPL

Title:[3013] X-rays from active regions on the Sun Caption:Hard and soft X-ray emission from active regions on the Sun, detected from Skylab (1973/4). The X-rays come from "hot spots" overlying cool sunspots in the Sun's photosphere below. Copyright: Credit:NASA/JPL

Title:[3014] Solar prominence and Sun in UV light from Skylab Caption:This ultraviolet image of the Sun from Skylab (1973/4) shows a very large prominence erupting from the solar surface. Copyright: Credit:NASA/JPL

Title:[3015] Coronal transient and eruptive prominence on the Sun from Skylab Caption:A coronal transient (light blue) ballooning outwards from the Sun. It was propelled by an eruptive prominence, shown in the ultraviolet image of the Sun which has been superimposed over the dark circle of the coronagraph used to image the corona. Copyright: Credit:NASA/JPL

Title:[3016] An eruptive solar prominence in UV light from Skylab Caption:This extreme ultraviolet image of the Sun from Skylab (1973/4) shows the size of a huge eruptive prominence compared with the size of Earth. Copyright: Credit:NASA/JPL

Title:[3017] Huge eruption from the Sun in UV light from Skylab Caption:This eruption of material from the Sun extends for more than 300,000 km above the Sun ten minutes after it was expelled from the surface. Seen here from Skylab (1973/4) in the ultraviolet light of ionized helium, its twisted form results from the structure of the Sun's magnetic field. Copyright: Credit:NASA/JPL

Title:[3018] Looped prominences on the Sun in UV light from Skylab Caption:The Sun's magnetic field causes material ejected from the surface to take on the looped paths seen here in ultraviolet light in an image taken from Skylab (1973/4). Copyright: Credit:NASA/JPL

Title:[3019] The Sun in soft X-rays from the Yohkoh orbiting observatory Caption:This image of the Sun was taken on 24 January 1992 with the soft X-ray Telescope on the Japan/US/UK orbiting Yohkoh mission. It reveals the three-dimensional structure of the hot corona across the whole of the Sun's disk. The bright areas are regions where hot gas at temperatures of over a million degrees K are trapped by the Sun's magnetic field. The dark areas are coronal holes, which are the sources of the solar wind ( streams of high speed particles ) which flows past Earth and through the solar system at about 700 km per second. Copyright: Credit:NASA