Science Photo Library

Blue Marble image of Earth (2005)

2008-05-25T17:10:28Z

Blue Marble image of Earth. Composite satellite image of Earth's western hemisphere, centred on the Atlantic Ocean. North is at top. The image is one of a set entitled Blue Marble: NextGeneration, released in October 2005, whichimproves upon Blue Marble 2000. The new images combine data collected over a longer period of time at an improved resolution of 500 metres per pixel. Features include cloud cover, oceans, phytoplankton activity, topography, and city lights in the nighttime part of the hemisphere. Data was obtained mainly by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra and Aqua satellites between July 2001 and July 2004. Topography is based on radar data collected by the Space Shuttle Endeavor.

Transit of Venus, 8th June 2004

2008-05-25T17:10:36Z

Transit of Venus. Composite image of Venus (black transiting the Sun on 8th June 2004. The images were taken from Waldenburg, Germany. The first image of Venus was taken at 05:41 GMT, and the last at 11:04 GMT. A transit occurs when Venus passes in front of the Sun as seen from Earth. This was the first transit since 1882. Venus is an Earth-sized planet that orbits in between Earth and the Sun. It does not appear to cross the Sun's disc during every orbit as the orbital paths of the Earth and Venus are not in exactly the same plane. Venus transits occur in pairs separated by eight years, with alternating intervals of 121.5 and 104.5 years in between pairs.

Waxing gibbous Moon, computer-enhanced

2008-05-25T17:11:03Z

Waxing gibbous Moon, computer-enhanced image. The colour saturation of this image has been enhanced to accentuate the natural variation in colour of the Moon's surface. This brings out the differences in surface composition, which reveals that the Moon's surface comprises many different minerals. For instance, deep craters excavate bright material from below the surface, and distribute it across the surface. The Moon is said to be waxing when it is increasing in apparent size. A gibbous Moon is one that is between half and totally full.

Jupiter, infrared Gemini North image

2008-05-25T17:11:08Z

Jupiter. Near-infrared image of Jupiter, showing the Great Red Spot (white) and a smaller red spot (Red Spot Junior) that formed between 1998 and 2000. The spots are a reddish colour in visible light. The colours here indicate cloud height, from high altitude (white), through blue to lower altitudes (red). The bright areas around the poles are polar stratospheric hazes. Jupiter's red spots are massive storm systems, tens of thousands of kilometres across and large enough to swallow Earth whole. The Great Red Spot has lasted for hundreds of years. Image obtained on 14 July 2006 by the Near-Infrared Imager (NIRI) at Gemini North, Hawaii, using the ALTAIR adaptive optics system.
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Jupiter's Great Red Spot

2008-05-25T17:11:26Z

Voyager 2 view of Jupiter's Great Red Spot, recorded on 6 July 1979 from a distance of 2.6 million kilometres. A long, narrow, white cloud is seen along the Great Red Spot's northern boundary; the presence of this cloud prevents small cloud vortices from circling the Spot in the manner seen by the Voyager 1 spacecraft three months earlier. The Great Red Spot is a massive and relatively stable storm system in the Jovian atmosphere; it has been seen from Earth for over 200 years.

Saturn silhouetted, Cassini image

2008-05-25T17:11:29Z

Saturn silhouetted. Cassini spacecraft image of Saturn and its ring system with the Sun directly behind. The view revealed two previously unknown rings. One, associated with the orbits of the moons Janus and Epimetheus, lies in between the outer edge of the bright main rings and the thin grey/brown G Ring. The other, associated with the orbit of the moon Pallene, lies just inside the broad and diffuse outer E ring. Earth is seen as a bright dot at the ten o'clock position between the bright main rings and the G Ring. This is a composite of 165 images taken at infrared, visible light and ultraviolet wavelengths by the Cassini spacecraft on 15th September 2006, while it was around 2.2 million kilometres from Saturn.

Comet C/2001 Q4

2008-05-25T17:12:00Z

Comet C/2001 Q4 on 7 May 2004, the day after it passed closest to the Earth. Q4 reached perihelion (closest point to the Sun) just over a week later, on the 15 May. A comet is a ball of water ice and dust, which has a highly elliptical orbit around the Sun. As comets approach the Sun, they develop a tail of vaporised gas and dust that always points away from the Sun due to the solar wind. This comet was discovered by the Near Earth Asteroid Tracking system (NEAT) project in 2001, and the image was captured by the WIYN 0.9-metre telescope at Kitt Peak National Observatory, USA.
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Comet McNaught, 20th January 2007

2008-05-25T17:12:32Z

Comet McNaught. This comet, also known as C/2006 P1, was the brightest to appear in the sky since Ikeya-Seki in 1965. Due to its proximity to the Sun it could only be seen at dusk. It was visible in the Northern Hemisphere until 13th January 2007, when it passed the Sun and became a Southern Hemisphere object. It attained a maximum brightness of magnitude -6 around 14th January. The tail is formed of particles of ice and dust expelled by the comet as it was heated by the Sun. The comet was discovered by Rob McNaught of Siding Spring Observatory on 7th August 2006. Photographed from Siding Spring Observatory, Australia, on 20th January 2007.
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Total solar eclipse, 29/03/2006

2008-05-25T17:13:01Z

Total solar eclipse. Sequence of images of the sun during a total solar eclipse. The disc of the moon is seen moving over the disc of the sun from left to right. At totality (centre) the moon fits over the sun and only the sun's corona (atmosphere) is visible. The moment of totality lasts for only a few minutes. Total solar eclipses usually occur less than once a year and can only be seen from a small area of the Earth's surface. Photographed on 29th March 2006.

Solar corona

2008-05-25T17:13:12Z

Solar corona. Ultraviolet SOHO (Solar and Heliospheric Observatory) satellite image of the corona (hazy) around the Sun. The corona, the Sun's outer atmosphere, is seen at three ultraviolet wavelengths, showing areas at: 1 million (blue), 1.5 million (green) and 2 million degrees Celsius (red). Details of the Sun's magnetic field are seen because it affects the charged atoms (ions) in the corona, forming the patterns seen here. Active areas of the Sun's surface are white. The activity of the Sun peaks every 10-11 years. This image is from SOHO's Extreme Ultraviolet Imaging Telescope (EIT) in May 1998, as the Sun neared the solar maximum in 2000.

Sun in hydrogen alpha light

2008-05-25T17:13:35Z

Sun, optical image in hydrogen alpha light. Hydrogen alpha (Ha) is a wavelength of light at which hydrogen absorbs and emits light. It has a wavelength of 656.3 nanometres, which is detected as red by the eye. Excluding all other wavelengths allows fine detail to be seen on the Sun. The visible surface (photosphere) comprises cells made up of areas of rising (hot) and falling (cooler) material. These are constantly shifting and writhing on the surface. Dark prominences and bright sunspots are also seen.

Solar coronal loops, TRACE image

2008-05-25T17:13:40Z

Solar coronal loops. Coloured ultraviolet TRACE image of coronal loops on the Sun following a solar flare event observed in November 2000. The bases of the loops are the hottest areas (white). These areas raise the temperature of the solar corona (atmosphere) thousands of times above that of the Sun's surface (dark, lower frame). The loops comprise electrically charged gases (plasma) at millions of degrees Celsius. Gas is heated as it is ejected from the surface, and follows the path of magnetic field lines before crashing back down on the Sun's surface at over 100 kilometres per second. TRACE (Transition Region and Coronal Explorer) is a space observatory launched in 1998 to study the Sun at ultraviolet wavelengths.

The Plough

2008-05-25T17:14:15Z

The Plough. Optical image of the group of stars known as The Plough (or Big Dipper) in the constellation Ursa Major, the Great Bear. North is at top. Ursa Major is the third largest constellation in the sky. The handle of the Big Dipper (centre left) forms the bear's tail, with the bowl (just right of centre) representing part of its back.

Orion constellation

2008-05-25T17:14:22Z

Orion constellation. The most prominent feature of the constellation is Orion's Belt, a row of three bright stars (centre left). From left to right, these are Alnitak, Alnilam and Mintaka (Zeta, Epsilon and Delta Orionis respectively). At upper left is the red supergiant star Betelgeuse (Alpha Orionis). The blue supergiant star Rigel (Beta Orionis) is at lower right. Directly below the belt, the Orion Nebula is seen as a pink smudge. Orion's belt straddles the celestial equator, so the constellation is seen equally well from both hemispheres. Photographed from Germany.

Cocoon Nebula

2008-05-25T17:15:02Z

Cocoon Nebula. Optical image of the Cocoon Nebula (IC 5146) in the constellation Cygnus. This is an emission nebula, a large cloud of gas and dust that glows due to the ionisation of its hydrogen gas by ultraviolet radiation from nearby stars. The image was produced using the Canada-France- Hawaii Telescope, Mauna Kea, Hawaii, USA.

Eagle Nebula

2008-05-25T17:15:08Z

Eagle Nebula. Optical image of the Eagle Nebula (M16, NGC 6611). This is an emission nebula, a cloud of gas that glows as the hydrogen gas it contains is ionised by radiation from the hot young stars within it. The stars in the cluster are about 5. 5 million years old, young in stellar terms. They formed from the coalescence of the nebula's gas. M16 is around 7000 light years from Earth in the constellation Serpens Cauda. This image was produced by a CCD (charge-coupled device) at the Kitt Peak National Observatory, USA.
*** THIS PICTURE MAY NOT BE USED TO STATE OR IMPLY NOAO ENDORSEMENT OF ANY COMPANY OR PRODUCT ***
** THIS PICTURE MAY NOT BE USED TO STATE OR IMPLY NOAO ENDORSEMENT OF ANY PRODUCT**

Antares/Rho Ophiuchi region

2008-05-25T17:17:48Z

Antares/Rho Ophiuchi region, optical image. This colourful region lies in the constellations Scorpius and Ophiuchus. The blue area at upper right is the triplet star Rho Ophiuchi, embedded in the reflection nebula IC 4604. This nebula does not emit light of its own, but reflects light from the star and appears blue due to blue light being scattered more than red light. The large orb at lower left is the supergiant star Antares (Alpha Scorpii), next to the yellow emission nebula IC 4606. This nebula emits light due to its gas and dust clouds being ionised by radiation from the stars. At right is the star Sigma Scorpii with its pink emission nebula Ced 130, and at lower right is the dense globular star cluster M4 (NGC 6121).

Horsehead nebula

2008-05-25T17:18:14Z

Horsehead Nebula, optical image. North is at left. The distinctive horsehead shape is formed by the dark nebula B33 being silhouetted against the bright emission nebulae IC 434 (pink). The glow is due to the ionisation of hydrogen by ultraviolet radiation from nearby stars. Photographed by the 8.2 metre VLT KUEYEN telescope at the Paranal Observatory, Chile, on the 1st February 2001.
THIS IMAGE MAY NOT BE USED BY OR TO PROMOTE THE ARMS, NUCLEAR POWER OR TOBACCO INDUSTRIES OR ANY RELIGIOUS ORGANISATION, OR IN ANY DISCRIMINATORY WAY, OR TO IMPLY THE ENDORSEMENT BY ESO OF ANY PRODUCT, SERVICE OR ACTIVITY.

Eta Carinae Nebula, HST image

2008-05-25T17:19:48Z

Eta Carinae Nebula, Hubble Space Telescope (HST) image. This large panoramic view covers an area 50 light years across, and was assembled from 48 images obtained by Hubble's Advanced Camera for Surveys in 2005. Colour information was added using the ground-based Cerro Tolodo Inter-American Observatory telescopes in Chile. The colours correspond to different elements: sulphur (red), hydrogen (green) and oxygen (blue). The Eta Carinae Nebula is around 10,000 light years from Earth in the constellation of Carina. The nebula is a large cloud of gas and dust, with a mix of hot, young stars, dying stars and regions of starbirth. The main star, Eta Carinae, is at far left.

Eta Carinae nebula, HST image

2008-05-25T17:19:56Z

Eta Carinae nebula. Coloured Hubble Space Telescope (HST) image of part of the Eta Carinae nebula. This large pillar of cold hydrogen gas and dust is the site of star birth. The narrow pillar (pointing towards top left) alone measures one light year in length. Two stellar jets, or Herbig- Haro objects (white streaks) are seen bursting from the cloud. The ultraviolet radiation in these jets, which are formed by the young hot stars, is slowly eroding the pillar. The Eta Carinae Nebula is around 10,000 light years from Earth in the constellation of Carina. Image taken using Hubble's Advanced Camera for Surveys.

Pleiades star cluster (M45)

2008-05-25T17:21:02Z

Pleiades star cluster (M45), optical image. This is the nearest major star cluster to Earth at just 440 light years away. It contains over 500 young stars, thought to be between 75 and 150 million years old. The blue reflection nebula surrounding the stars is not the remnants of the nebula from which they formed, as was once thought, but instead a gas and dust cloud that the nebula is passing through by chance. The particles in it reflect the light of the stars. The Pleiades cluster is in the constellation Taurus.

Hercules globular cluster (M13)

2008-05-25T17:21:12Z

Hercules globular cluster (M13), optical image. Globular clusters are groups of old stars that orbit a galaxy. They are tightly bound by gravity, giving them a spherical shape. The Hercules cluster, orbiting the Milky Way galaxy, consists of hundreds of thousands of stars and is 168 light years across. It lies around 25,100 light years from Earth in the constellation Hercules.

Core of Omega Centauri globular cluster

2008-05-25T17:24:35Z

Core of Omega Centauri globular cluster (NGC 5139), Hubble Space Telescope image. Globular clusters are spherical clusters of very old stars, about 12 billion years old, that are tightly bound by gravity and orbit a dense central core. This cluster is the largest globular star cluster found orbiting the Milky Way. This image shows an area 50 light years across and containing around 2 million stars. The entire cluster is 150 light years across and contains some 10 million stars. Omega Centauri is around 18,000 light years from Earth, in the constellation Centaurus. This image, based on optical and infrared light, was obtained in June 2002 with the Advanced Camera for Surveys.

Orion's belt

2008-05-25T17:24:56Z

Orion's belt. Optical image of the line of three bright stars making up the 'belt' in the constellation of Orion. The stars are, from lower left to upper right: Alnitak (Zeta Orionis), Alnilam (Epsilon Orionis) and Mintaka (Delta Orionis). The reddish area at lower left is a region of emission nebulosity, in which radiation from the nearby stars ionises hydrogen gas, causing it to glow.

Wolf-Rayet nebula NGC 2359

2008-05-25T17:26:24Z

Wolf-Rayet nebula NGC 2359, optical image. This nebula, lying around 40,000 light years from Earth in the constellation Canis Major, is sometimes known as Thor's Helmet. A Wolf-Rayet nebula is formed by the ejection of glowing, ionised gas from a hot, central star. These Wolf-Rayet stars lose mass 100 times faster than stars of comparible luminosity and may be a million times more luminous than the Sun. The interaction of the ejected gas with interstellar matter forms a bubble around the star, which glows when ionised by the star's radiation.

Helix Nebula, HST image

2008-05-25T17:26:38Z

Helix Nebula. Hubble Space Telescope image of the Helix planetary nebula (NGC 7293). This comprises shells of gas cast off a Sun-like star near the end of its life. The colours are due to gases in the shells being ionised by radiation from the central star that ejected them. The blue colour comes from oxygen and the red from hydrogen and nitrogen. Despite its ring shape, it is thought that the nebula is actually a cylinder aligned end on to Earth. This is one of the nearest planetary nebulae to Earth, lying 650 light years away in the constellation Aquarius. It is 3 light years in diameter, and appears half a Moon-width wide.

Planetary nebula, X-ray composite

2008-05-25T17:27:00Z

Planetary nebula. Combined X-ray and optical image of the planetary nebula Mz 3 (also called the Ant Nebula). A planetary nebula is a bubble of hot gas and dust, many times the size of our solar system, expanding outwards from a dying, Sun-like star. The nebula consists of the ejected outer layers of the star. The optical part of this image (orange) was obtained with the Hubble Space Telescope (HST). The hotter, X-ray emitting regions (blue and white, inside the two lobes) was imaged with the Chandra X-ray Observatory (CXO). Both the HST and CXO are telescopes in Earth orbit. Mz 3 is around 3000 light years from Earth, in the constellation of Norma.

Supernova remnant W49B

2008-05-25T17:27:03Z

Supernova remnant W49B, composite image. Located 35 thousand light years away in the Aquila constellation, this image shows an intense X-ray source (blue), surrounded by infrared rings (red and green). The X-ray source is 15 million degree Celsius gas comprised of iron and nickel ions, whereas the infrared sources are mainly hydrogen molecules. It is believed these formations are the aftermath of a massive star which shone for a few million years, spinning off rings of gas. Eventually losing most of its fuel it collapsed to form a black hole, ejecting material rich in iron and nickel. This material hit the cloud surrounding the star, flaring out and creating a shockwave. Chandra and Palomar space telescopes.

Veil nebula supernova remnant

2008-05-25T17:28:08Z

Veil nebula supernova remnant, NGC 6992 (optical image). This is the easternmost region of the Veil nebula, part of the Cygnus Loop, which is the remnant of a supernova that exploded some 5-8000 years ago. The gas ejected from the explosion expands outwards, colliding with interstellar material at high speed. The shock of the impact ionises the gases, causing them to glow. The roughly circular Cygnus loop describes the outer shell of these expanding gases. The nebula lies about 1400 light years away in the constellation Cygnus.

Supernova remnant IC 443, composite image

2008-05-25T17:28:23Z

Supernova remnant IC 443, composite image. This is a combination of X-ray (blue), radio (green) and optical (red) data. A supernova remnant (SNR) is an expanding shell of dust and gas that forms following the explosive death of a massive star. The collision of the ejected material with the interstellar medium is causing the material to heat up and glow. IC 443 is thought to have formed some 8000 years ago. It is around 5000 light years from Earth, in the constellation of Gemini. The data, from January 2005, was obtained by ROSAT and the Chandra X-ray telescope (X-ray), the Very Large Array (VLA, radio), and the Digitized Sky Survey (DSS, optical).

Crab nebula, composite image

2008-05-25T17:30:09Z

Crab nebula. Composite x-ray, infrared and optical image of the Crab nebula (M1), a remnant of a supernova that exploded in AD 1054. The Crab lies in the constellation Taurus, some 6000 light years from Earth. The central light blue region is ultra high energy X-ray emission, dark blue and green regions are in visible light and the red regions are low-energy infrared emission. X-ray data from Chandra, visible light data from Hubble and infrared data from Spitzer, all taken on 31st January 2001.

Milky Way

2008-05-25T17:30:14Z

Milky Way. Mosaic of photographs of the Milky Way, the spiral galaxy in which our solar system lies. Our Sun is believed to be around two-thirds of the way out from the centre in a small spiral arm. Galactic Centre lies at the centre of the image in the constellation Sagittarius. This is where the bulge of stars in the Milky Way is at its greatest, tapering away on either side. The image runs around the whole of the sky, so our view away from Galactic Centre is seen both at far left and at far right. Interstellar dust obscures much of the Galaxy's central axis. The Milky Way is thought to be about 120,000 light years across and to contain over 100 billion stars.

Hubble Ultra Deep Field galaxies

2008-05-25T17:31:29Z

Ultra Deep Field galaxies. Hubble Space Telescope Ultra Deep Field, the deepest view ever taken of the universe in 2004. Each dot of light is a separate galaxy. Some of these are amongst the most distant objects ever seen, over 13 billion light years away, and thus over 13 billion years old. To detect these extremely faint galaxies, the HST focused its ACS and NICMOS cameras on an apparently empty patch of sky for one million seconds. The infrared NICMOS data shows galaxies at a redshift of up to 12, which were among the first objects to form in the universe after its birth 13.7 billion years ago.

Cartwheel galaxy, multi-wavelength image

2008-05-25T17:31:44Z

Cartwheel galaxy, multi-wavelength image. Around 100 million years ago, a smaller galaxy passed directly through the centre of the Cartwheel galaxy. This caused shock waves to propagate out through the galaxy, which caused bursts of star formation. The bright blue ring marks the region where huge, powerful ultraviolet-emitting stars have formed. The inner orange ring is the second wave, but this has far less star formation than the first wave. It is not known if the colliding galaxy was one of the two at lower left. The images were taken in X-rays by the Chandra Space Telescope (purple), in UV by GALEX (blue), in green light by the Hubble Space Telescope, and in infrared by the Spitzer Space Telescope (red).

Antennae galaxies, HST image

2008-05-25T17:32:10Z

Antennae colliding galaxies, Hubble Space Telescope image. The Antennae (NGC 4038 and NGC 4039) are formed of two galaxies colliding due to mutual gravitational attraction. The nuclei (yellow) of the galaxies are at lower left and upper right. Numerous dark lanes of dust are seen silhouetted against the bright parts of the galaxies. The interaction has caused a huge swathe of starbirth, as seen by the abundance of young blue stars and the vast pink emission nebulae, in which stars are born. The Antennae lie some 62 million light years from Earth in the constellation Corvus. Image data collected by the Advanced Camera for Surveys in 2004 and 2005.

Fornax A galaxy

2008-05-25T17:32:18Z

Fornax A galaxy. Combined optical (white) and radio (orange) image of the galaxy Fornax A (NGC 1316, centre). The smaller galaxy NGC 1317 is above it. These galaxies are members of the Fornax cluster, a gravitationally linked group of 18 galaxies which lies around 70 million light years from Earth in the constellation Fornax. o'=Fornax A is a powerful source of radio waves (orange). These radio emissions are powered by a massive black hole at the galaxy's centre. Image produced using radio data from the Very Large Array (VLA) telescope.
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Large Magellanic cloud

2008-05-25T17:34:14Z

Large Magellanic Cloud (LMC), infrared image. The LMC is a dwarf galaxy, and a satellite of our own Milky Way galaxy. It contains regions of emission nebula (green, yellow and red), where radiation from hot young stars ionises surrounding gas, causing it to glow. There are also reflection nebulae (shown in blue), caused by dust reflecting the light of nearby stars. This image is a mosaic of over 300,000 tiles taken with NASA's Spitzer Space Telescope, an observatory orbiting the Earth.

Small Magellanic Cloud, optical image

2008-05-25T17:34:23Z

Small Magellanic Cloud, optical image. The Small Magellanic Cloud (SMC) dwarf galaxy is a satellite galaxy of our Milky Way. It contains numerous emission nebulae, which are clouds of gas that glow red as the hydrogen gas they contain is ionised by radiation from nearby hot young stars. The bright, round object at upper left is the globular star cluster 47 Tucanae. The SMC lies about 185,000 light years from Earth, in the constellation Tucana.

Andromeda Galaxy, UV image

2008-05-25T17:35:58Z

Andromeda Galaxy (M31), ultraviolet image from the GALEX satellite. Two regions of the ultraviolet (UV) spectrum were examined, the far (FUV) and the near (NUV) regions. FUV (blue) is from the young, bright stars in the galaxy's spiral arms. The NUV emissions (orange) show the older stars in the galaxy's centre, as well as foreground stars from the Milky Way. M31 is the nearest large galaxy to our own. It is 150,000 light years across and 2.2 million light years distant. Image data obtained in 2003. The GALEX (Galaxy Evolution Explorer) satellite is designed to use UV sensors to study the evolution of galaxies.

Andromeda galaxy (M31)

2008-05-25T17:36:09Z

Andromeda galaxy (M31), optical image. Andromeda, lying only 2.5 million light years away, is the closest major galaxy to our own. Like our galaxy, the Milky Way, it is a barred spiral galaxy, spiral in form but with a bright band of stars across the centre. With a diameter of 150,000 light years, it is about half as large again as the Milky Way. The older stars towards the centre of the galaxy make its core appear yellow. The two bright objects close to the galaxy are Andromeda's two satellite galaxies, M32 (bottom centre) and M110 (just upper left of centre). The galaxy is named after the constellation Andromeda, where it is found.

Pinwheel galaxy

2008-05-25T17:37:29Z

Pinwheel galaxy (M33), optical image. This spiral galaxy is part of the Local Group of galaxies that also includes our Milky Way and the Andromeda galaxy. It is much smaller than our galaxy and Andromeda, though. Its spiral arms contain a large number of starbirth regions (pink). These are giant nebulae, which glow pink as radiation from the newborn stars ionises hydrogen in them. This galaxy lies just three million light years away in the constellation Triangulum.

Whirlpool galaxy

2008-05-25T17:37:39Z

Whirlpool galaxy (M51), Hubble Space Telescope image. The large spiral galaxy M51 is interacting with its small companion (NGC 5195, right). The spiral arms of M51 are studded with pink starbirth regions, which glow as radiation from the newborn stars within them ionises the hydrogen they contain. The regions between the spiral arms look relatively empty, but they are actually criss- crossed by dark dust lanes. This pair of galaxies is thought to lie about 37 million light years away in the constellation Canes Venatici. This image is a mosaic of images taken by the Advanced Camera for Surveys (ACS) on the HST in January 2005.

Stephan's quintet

2008-05-25T17:38:00Z

Stephan's quintet. Optical image of Stephan's quintet. This group of galaxies is 300 million light years from Earth in the constellation Pegasus. It consists of NGC 7320 (upper right) NGC7319 (lower right), NGC7318A and B (centre left) and NGC7317 (upper left). The galaxies are so close together they are tearing each other apart with gravitational tidal forces, leaving trails of dust and gas. The red areas are hydrogen clouds and sites of star birth. It is argued that NGC7320 is not actually part of the cluster, but lies in the foreground.
*** THIS PICTURE MAY NOT BE USED TO STATE OR IMPLY NOAO ENDORSEMENT OF ANY COMPANY OR PRODUCT ***

Hickson Compact Group 44 galaxy cluster

2008-05-25T17:38:04Z

Hickson Compact Group 44 galaxy cluster, optical image. This is a cluster of galaxies that lies around 60 million light years from Earth in the constellation Leo. The dominant galaxies in the cluster include NGC 3190, the large spiral galaxy above centre. At upper left is the elliptical NGC 3193. NGC 3187 is just right of upper centre, and displays a prominent central bar from which its arms extend. NGC 3185, at lower right, is also a barred spiral galaxy, but the bar is less obvious. The galaxies are gravitationally bound to each other, and their interactions have distorted their shapes.

Bullet cluster (1E 0657-56)

2008-05-25T17:38:24Z

Bullet cluster (1E 0657-56), X-ray image. The bullet cluster, which lies in the constellation Carina, contains two colliding galaxies. The normal matter in the cluster is shown here in pink. Background material is also visible as a result of gravitational lensing, or the distortion of light by the huge mass of the galaxies. This reveals dark matter, matter that does not emit or reflect visible light or radiation, but can only be detected by its gravitational effects on normalmatter. This is shown here in blue. This image was taken by the Chandra X-ray Observatory, a telescope orbiting Earth.

Hubble Space Telescope image of the Einstein cross

2008-05-25T17:38:27Z

Gravitational lensing. Hubble Space Telescope image of the 'Einstein cross' G2237 +0305, also known as Huchra's cross after its discoverer John Huchra. The photo shows five images; the central spot is a relatively nearby galaxy, while the four outer spots are images of a distant quasar. Light from the quasar has been bent by the gravitation field of the intervening galaxy, which acts as a giant lens, forming four images of the quasar. The quasar lies at a distance of around 8 billion light years, while the galaxy is 20 time closer at 400 million light years. Einstein proposed the effect of gravitational lensing in 1936.

Dark matter gravitational lensing

2008-05-25T17:39:08Z

Gravitational lensing by dark matter in the galaxy cluster CI 0024+17, Hubble Space Telescope image. The cluster galaxies are bright yellow, the far more distant lensed galaxies appear as elongated blue smears. Gravitational lensing is an effect whereby the path of light from distant objects is bent and magnified by the gravity of a sufficiently massive foreground object in the same line of sight. The amount of lensing can be used to determine the mass of the foreground object. By this method, the cluster was found to contain a vast ring of dark matter (see image R980/230), providing the best evidence yet of its existence. Image taken by the Advanced Camera for Surveys on the HST in November 2004.

Cosmic microwave background, WMAP image

2008-05-25T17:39:16Z

Cosmic microwave background. WMAP (Wilkinson Microwave Anisotropy Probe) spacecraft whole sky image of cosmic microwave background. This map indicates that the age of the universe is around 13.7 billion years and that the universe is expanding at a rate of about 71 kilometres per second per megaparsec (1 Mpc = 3262 light years). The colours represent the varying densities of the early universe as it was about 380,000 years after its formation. The denser regions (red, yellow) formed the seeds of galaxies and other structures. The WMAP sky survey commenced on 11th February 2003. This 5-year WMAP image was produced on 28th February 2008.

Corona Australis

2008-05-25T17:40:57Z

Corona Australis reflection nebula.

Lunar eclipse

2008-05-25T17:41:21Z

Lunar eclipse, 30th December 1982.