Superearth Gliese 876 d is only 7.5 Earth masses, making it as of mid 2005 the smallest extrasolar planet known around a normal star. At such a low mass, it must be composed primarily of rock, although its rocky surface may lie beneath a thick layer of super condensed volatiles and a dense atmosphere. If, on the other hand, most of the planet's volatiles have been lost to early bombardment or were never present in large quantities, the rocky surface of Gliese 876 d may be visible from space. Baked both internally by the heat of radioactive decay and externally by its close proximity to its star, such a massive terrestrial world have a thin crust riddled with tectonic rifts and possibly even oceans of magma exposed on the surface.

Before the thin blue crescent of 70 Virginis b hangs a small moon so severely heated by tidal stress that lakes of molten lava glow on its surface. No lightning sparkles on the night side of the planet itself, as it completely lacks surface clouds. In the distance, the star 70 Virginis shines brightly

Off the limb of Gliese 876 c looms the bright disk of Gliese 876 b. During close approaches such as this, the two giant planets are only about a tenth of an AU apart.

The night side of gamma Cephei Ab flickers with titanic lightning storms. Only a thin sliver of the planet and its moon remain in sunlight from this vantage point. In the distance, the planet's two stars glow. The nearby K1 subgiant shines brightly, but the light of the M1 red dwarf, 13 AU away, is feeble and distant.

A rocky moon, its pole capped with water ice, orbits the outer planet of Gliese 876. The giant planet's water ice clouds are tinged yellow-orange by the low spectrum light of the red dwarf parent star.

Obsolete portrait. A rocky moon of Gliese 876 c with the mass of Mars or even the Earth may be warm enough for liquid water to form small seas on its surface. What kind of life might form in the dim yellow glow of a red dwarf star?

Living for only a few million years, the first generation of stars end their lives in brilliant supernovae, filling the young universe with heavy elements from which, one day, planets such as Earth will form.

Hot Jupiters that are below 1500 K are not hot enough for silicates to condense at the top of the atmosphere. Instead of bright clouds, such planets are instead shrouded in a thick layer of sodium haze, rendering the surface completely dark.

Sodium gas may give Hot Jupiters like 51 Pegasi b a dark grey or brown appearance. 51 Pegasi b itself may be lightweight enough and hot enough for clouds of silicates to form, girdling the planet in white.

The planet of HD 209458, unofficially named Osiris, is so close to its star that its atmosphere is literally boiling away into space. Here we see the dim blue glow of energized hydrogen gas escaping the planet's atmosphere, extending into a comet-like tail.

With lunar mass and a composition similar to Mercury, the heavily cratered surface of PSR 1257+12 a is laid bare before the onslaught of the pulsar's particle winds. Ions excited by these winds give off a glow barely discernable in the faint and cold light of the dead star.

Upon an Earth sized rocky moon of HD 28185, safe beneath a nitrogen atmosphere and a strong magnetic field and nurtured by temperate oceans of liquid water, life flourishes. Although mere speculation, the existence of a living moon such as this one is almost guaranteed somewhere in the galaxy.

Gigantic oceans of water girdle HD 28185 b. But these oceans are not liquid, they are clouds of ice crystals. Here, we see a cloudscape akin to what might be found on our own world, but on a much vaster scale. In the distance, two of the planet's moons are lit by the morning sun. If one of these moons is large enough and far enough from the planet's super energetic magnetic field, it my harbor oceans of its own. Oceans of a more familiar variety.

Obsolete portrait. The sun rises upon a blistering skyscape of titanic silicate clouds and storms of raining iron. Far below, the atmosphere becomes a crushing inferno and glows red from the seething temperatures.

Obsolete portrait. The first planet ever detected around a sun-like star, 51 Pegasi b was also the first "Hot Jupiter" ever discovered. Here we see the planet's sunlit side. The edges of the planet are blue from Rayleigh Scattering, but it glows red from beneath sparse silicate clouds towards the center of its disk. Superheated by its torturously close parent star, 51 Pegasi b's atmosphere is bloated and is slowly evaporating into space.

The hottest of the "Hot Jupiters", tau Bootes b is cooked externally by its close proximity to its F class star and internally by the heat of its formation. Yet, it has a firm hold on its material due to it's high mass, four times that of Jupiter. It's atmosphere is so torrid that clouds of silicates form and cover much of the planet.

55 Cancri b and c are closest when the two planets align with their sun while Planet c is at periastron. When this happens, the two planets are separated by only 0.015 AU. That's a little over two million kilometers, or about six times the distance from the Earth to the Moon. Here, we see an alignment of worlds, with 55 Cancri c and it's moon in the foreground. Beyond hangs 55 Cancri b, as well as the parent star itself with 55 Cancri e in transit across its disk. So close are Planets b and c that the inner world's night side is dimly lit by sunlight reflected from the outer

At periastron, 55 Cancri c is not much further away from its star than 55 Cancri b, and the planet would heat up dramatically. As temperatures rise with the approach of summer, the planet's clouds disperse, leaving only a few lingering wisps at the poles. The majority of the planet's surface becomes blue and featureless, just like it's more massive sibling, Planet b.

55 Cancri c's orbital distance and eccentricity make it possible that the planet has not yet been tidally locked by its parent star. If this is the case, it may have a retinue of moons, some of which may be as massive as Mercury. Here we see an airless and heavily cratered rocky moon with the blue planet beyond girdled in bands of white clouds.

55 Cancri b would be easily visible from its inward sibling, especially when its opposition coincides with the smaller world's apastron. Here, the volcanic plains and lava seas of "Super Earth" 55 Cancri e are girded in the blue haze of its thick, yet cloudless, atmosphere as the deep blue globe of 55 Cancri b hovers beyond.

An asteroid in a captured orbit glides past the deep blue disk of 55 Cancri b as superbolts of lightning arc deep within the nearly featureless atmosphere. A common sight from this world is the transit of its smaller sibling, 55 Cancri e, across the brilliant disk of its parent star.

Deep within the M4 globular cluster, the oldest known planet orbits a millisecond pulsar and its white dwarf companion. Dubbed "Methuselah" by astronomers, this planet is probably only a billion years younger than the universe itself. Here we see this ancient world from one of its moons. To the top left of the planet are its pair of tiny elderly parent stars. To the far left, the center of the M4 cluster looms like a gigantic swarm of bees.

HD 46375 b was one of the first extrasolar planets discovered with a mass similar to Saturn. This planet is epistellar, a smaller sibling to Hot Jupiters like 51 Pegasi and tau Bootes. Here we see the planet's glowing red surface covered by clouds of silicate vapor. Superbolts of lightning dot the planet's night side. Any moons of this world would be scorched, rocky, and barren.

The red giant Aldebaran dominates the skies near the star's massive companion. As the dying star sheds dust and gas, some of this material is trapped by the companion's gravity, settling into a tenuous dark ring. Below us and in the foreground, one of the companion's moons, it's rocky surface melted by stellar outbursts, broils in the scorching heat of the giant star. If Aldebaran replaced the sun in our own solar system, its surface would extend halfway to the orbit of Mercury.

On the equator of gas giant upsilon Andromedae d, we float above the main cloud deck of water ice clouds. On the horizon, the sun is setting. Bisecting our view, we see the rings of the third planet as a thin line, glowing in the waning light. The shadow of the rings paints a dark swath on the cloud tops below. Within the rings, small shepherd moons glow like tiny diamonds. The planet’s larger more distant moons can be seen arrayed in line with the rings. In the distance, two bright stars defy the light of the setting sun. These are the first and second planets of upsilon Andromedae.

The innermost of the three known worlds of upsilon Andromedae hugs it star in an orbit so tight that the planet glows red from the incident heat and clouds of ice particles cannot form. Tidally locked long ago, one side of the planet always faces its sun. The temperature at the spot closest to the sun is so high that gases are ignited and rush to the cool side of the planet. No calm cloud bands here, this is a seething atmosphere constantly turning itself inside out.

In orbit around Ganymede, the largest moon in the solar system, we see a grand vista of Jupiter's entourage. Icy Europa floats like a pearl. Volcanic Io sits enshrouded in a dim cloud of sodium and sulfur. And dominating the sky sits the king of worlds, whose night side flashes with super bolts of lightning.

Obsolete portrait. A moon half the size of Earth orbits at a comfortable distance from 70 Virginis b's magnetic field. Under its thin atmosphere we see lakes of liquid water in which simple life forms may exist.

While observers in the Pacific Ocean are seeing the Moon pass in front of the Sun, viewers on the Moon watch their own shadow pass across the Earth.

At the center of the Virgo Cluster, an inhabited Earthlike world and its moons float high above a massive spiral galaxy. In the distance is the giant elliptical galaxy M-87, as well as other denizens of the deep.

On a fictional desert world, twin moons rise into the sky.

The glacier covered moon of 47 Ursae Majoris' planet. Deep below the icy surface may exist an ocean of liquid water, and possibly, life.

In this montage we see Mars both from the surface and from space as it appeared a billion years ago, as it appears today, and as it may appear in the future.

Above the nearly featureless clouds of Lalande 21185 C, the planet's dark rings and moons orbit in frigid darkness.

We stand on the cracked and eroded surface of Venus. Here, the atmospheric pressures and temperatures are so great that the image is refracted, curving upwards at the edges.

On the frozen Saturnian moon Enceladus a water-ice geyser erupts into the sky. Some theories suggest that such geysers feed Saturn's faint E ring.

Obsolete portrait. From the surface of a shattered moon of 51 Pegasi B we see a flurry of bolides raining from the sky. In the foreground, steam evacuates from a recently opened fissure. In the background, the tortured face of 51 Pegasi B rises into the sky.

A ringed Earth-like world hangs like a jewel against the black of night...waiting for us.

The delicate ring system of a Jupiter sized world is backlit by the planet's companion star. In the foreground, ice geysers erupt on one of the planet's moons. In the distance, new stars are born in a nearby nebula.

Deep within the Kuiper Belt, a pair of icy worldlets drifts through the frigid dark. In the distance, the sun shines coldly and Jupiter and Saturn can be barely discerned. The nearest object is a billion kilometers away.

A portrait of Frank Herbert's legendary desert world Arrakis and its First and Second moons.

On the surface of Titan, the atmosphere is so thick with haze can barely see the ethane lake before us and the mountains of ice beyond. Above, the sky is opaque with clouds rich in organic molecules.

Discovered using gravitational lensing, this Earth mass planet was detected in a distant galaxy. Besides its mass, we know nothing about it.

A massive planet or brown dwarf may orbit beta Pictoris, causing the observed warping in the star's protoplanetary disk. Here we see the planet and it's moons. In the distance we see the disk edge on arcing through the sky.

Obsolete portrait. One of the most massive "Hot Jupiter" discovered so far, the atmosphere of the planet orbiting tau Bootes is slowly evaporating into space. Of all the "Hot Jupiters", this one has the most severe combination of stellar temperature, stellar distance, and internal temperature.

Like all of the gas giants of our own systems, it is likely that at least some of the newly discovered massive extrasolar planets have a system of rings. Within the rings of the planet orbiting 47 Ursae Majoris, we see millions of the icy fragments girdling the planet.

Obsolete portrait. The planet orbiting 70 Virginis is close enough to its sun that liquid water may exist on its moons. Here, we stand at the edge of a sea on a moon about the size of Mars. We can only speculate on the possibilities of life in such an environment.

Obsolete portrait. Battered by radiation and twisted by tidal forces, the tortured surface of 51 Pegasi B burns under the glare of it's nearby sun.

Oceans of lava glow red on the nightside of Gliese 876 d. The dayside of the planet broils in the yellowish light of the planet's host red dwarf star. In the distance glow two bright "stars", planets c and b of Gliese 876.

Orbiting the K0 star HD 69830, a pair of asteroids swings by a hypothetical Saturn mass water cloud giant and its moon. In the distance, dust in the star's thick belt, glows 1000 times brighter than our own star's zodiacal light.

A moon two and a half times as massive as Earth and choked by a thick atmosphere of carbon dioxide and sulfurous haze passes in front of the deep blue, cloud-free disk of 70 Virginis b. Far off drifts another moon, smaller and tortured by tidal stresses.

Reflecting the dim light of its parent red dwarf star, the bright water clouds of Gliese 876 c appear yellowish. In the foreground, a tiny rocky moon with barely the mass of Pluto orbits above the planet. The planet's dark rings bear witness to more massive moons that were long ago disrupted by tidal forces.

Photochemically generated sulfurous compounds stain the water clouds of gamma Cephei Ab yellow. In the foreground, a dense rocky moon with the mass of Mercury bears the scars of tectonic fractures and basaltic lava plains caused by the intense gravitational tides of its parent jovian.

Gliese 876 b hangs in the glow of its parent star, the disk of which is partially obscured by a transit of Gliese 876 c.

Obsolete portrait. Reflecting the dim light of its parent red dwarf star, the bright water clouds of Gliese 876 c appear yellowish. In the foreground, is a rocky moon with the mass of Mars. Far off, the bright disk of Gliese 876 b hangs amongst the stars

Shrouded in the clouds of pure hydrogen from which they formed, the first generation of stars burn brightly into a universe previously devoid of light.

Buffeted by hurricane force winds hot enough to vaporize Magnesium, we descend into the atmosphere of 51 Pegasi b. Before us is a blistering skyscape of silicate clouds colored brown by complex chemical stains forged in the intense radiation of the planet's nearby sun. Below us, the atmosphere is darkened by a thick layer of sodium vapor. Amongst the white silica clouds above us, the sun is motionless, anchored in eternal sunset by the tidally locked rotation of the planet.

From the vantage point of the Earth, the planet of HD 209458 moves across the face of its star once every few days. Such transits allow astronomers to probe the planet's atmosphere. A surprising discovery was that the planet heated to such high temperatures by it star, that its atmosphere is slowly escaping into space, forming a long tail that dims the star as it trails behind the planet.

From the surface of PSR 1257+12 a, the parent pulsar is only as bright as the full moon. There is no magnetic field here, and no atmosphere. Nothing to protect the little world from the barrage of subatomic particles streaming from the stellar remnant. The horizon faintly glows with the blue light of ions excited by this pulsar wind, a small touch of color to an otherwise dim and desolate world.

More massive than Jupiter, 55 Cancri d is, nonetheless, one of the few planets so far found at Jupiter like orbital distances. Here we see the gas giant with its retinue of moons.

HD 28185 b orbits within the habitable zone of its star. Although the planet itself is a gas giant with no solid surface, it may have rocky moons, some as large as Earth. Such moons would have similar climate to the Earth as well and might have an atmosphere, oceans, and even, possibly, life.

On a morning within the atmosphere of 55 Cancri b, a vast dome of blue surrounds us both above and below. In the distance, rare sulphurous clouds had formed in the relative coolness of night but now burn off in the heat of the risen sun. Soon, the sky will be nearly featureless save for a dusty band of haze girdling the horizon.

The night side of 51 Pegasi b is aglow with the heat of the planet's formation from beneath dark silicate clouds.

As the disk of tau Bootes b slides in front of its F class star, we see the planet's night side glow dimly from internal heating, partially obscured by clouds of superheated silicates.

Gliese 777A B is more like our own system's Jupiter than any other planet so far discovered.

From orbit around 55 Cancri c, we zoom in on the two degree disk of the system's parent star, 0.2 AU away, and witness a rare double transit of the two inner planets.

Especially at apastron, temperatures on 55 Cancri c may be cool enough to allow clouds to exist in parts of the atmosphere, but much of the planet would still be clear and rendered blue by Rayleigh scattering. Here we see the planet face on, its turbulent bands of clouds floating on a bottomless sea of blue. The clouds might be composed of sulfur compounds like those on Venus or, possibly, of water.

Current theory suggest that 55 Cancri e is a super terrestrial world robbed of a chance to become a gas giant by the early inward migration of its more massive sibling. Here we see the surface of 55 Cancri e, still seething from the intense heat of its formation and boiling under its nearby sun. The crust of the planet is only a few kilometers thick, and lava lakes and oceans cover large portions of the surface. The sky is a clear blue, though the air is so thick that the disk of the sun is blurred markedly. A low lying sulfur haze hangs low on the horizon. The temperature here is too hot for normal clouds to form, but rare clouds of silicate dust can form after eruptions.

55 Cancri e was the second "Super Earth" discovered. We currently don't know whether this world is a supermassive rocky planet or a pint sized jovian, but planet formation theory seems to suggest that it is the former. If so, a terrestrial planet seventeen times more massive than Earth situated in a tight orbit around its star would be a hellish inferno Here, lakes and even oceans of lava glow red on the night side of the planet from beneath a crushing atmosphere too torrid for even clouds to form.

The second "Hot Jupiter" to be discovered, the planet orbiting 55 Cancri is too close to its star for clouds to form. Instead, we see deep into the planet's seething atmosphere, colored blue by Rayleigh scattering.

79 Ceti b was one of the first extrasolar planets discovered with a mass similar to Saturn. This planet has an eccentric orbit slightly smaller than that of Mercury. Too close in for white water vapor clouds to form, but too far out to glow red from stellar heating, the surface of this world is a nearly featureless blue due to Rayleigh scattering. The planet is accompanied by its host of rocky moons and dusty rings.

The epistellar planet HD 209458 B has an orbital inclination of 90 degrees, meaning that it passes in front of its star from the vantage point of Earth. Here, the planet glows red from the severe heat of the nearby sun as it passes in front of the stellar disk. In the foreground is a small asteroid trapped by the planet's gravitational pull. The glasslike surface of the asteroid has been repeatedly melted by superflares from the nearby star.

Here we view u And b face on. Floating above a wayward asteroid, we have our backs to the sun, and the planet stares back at us with an otherworldly glare. The intense solar wind from the nearby sun is blowing material from the asteroid, forming a dusty tail. In the background, we see two bright stars, the second and third planets of upsilon Andromedae.

Too hot for white ice crystal clouds to form, but too cold for the planet to glow red, upsilon Andromedae c is colored blue by Rayleigh scattering. In the foreground, a Mars-like moon undergoes a global dust storm.

On the antisunward side of upsilon Andromedae b, we can see the planet's red glow. At the antisunward pole, the point farthest from the sun, the atmosphere resides in perpetual dark, and is thus cool enough to permit an "ice cap" of high clouds of water ice to form.

Recent studies of Pluto's moon Charon show that it may have an ocean of liquid water and an active core. Here, we look up from inside a fissure in moon's icy surface. Strange creatures feed off of the heat and gases venting from deep underground. Above floats frozen Pluto and the far away sun.

The massive substellar companion of Proxima Centauri glows red through internal heating. Proxima itself, a violent flare star and our closest stellar neighbor, is eclipsed by one of this world's moons. In the far distance, we see the other two members of this triple star system, Alpha Centauri A and B.

Recently photographed by Hubble, TMR-1c appears to be a 2-3 Jupiter mass protoplanet in the process of being ejected from the double star system in which it was created.

Descending into the atmosphere of Jupiter, we see the sunlit ring of the massive planet, as well as the innermost major moon, Io.

The frigid surface of Triton, one of only two moons in the solar system to have a permanent atmosphere. In the background, Neptune and its rings hang in the dark day time sky.

The hub of the Milky Way Galaxy dominates the skies of an arctic world close to the galactic core. Sharing the skies with the galactic center is the planet's large moon, a supernova remnant, and several nearby stars.

Phobos and Deimos rise into the salmon colored sky of Mars as carbon dioxide sublimates into a morning mist, standing out against the rusty surface.

Ringed Lalande 21185 B and its moons are dimly lit by its distant red dwarf sun.

Obsolete portrait. Lightning bursts as large as Earth flash across the dimly glowing night side of titanic 70 Virginis B. In the foreground, we see the orange glow of volcanism reshaping the dark side of one of the planet's moons.

A portrait of majestic Saturn and her cloud enshrouded moon Titan.

A sun-like star, having run out of hydrogen fuel, has swollen into a red giant, filling the sky of an unlucky Earth-like world.

A house sized comet breaks apart as it approaches Earth. Some suggest that every year millions of these "microcomets" deposit water in Earth's atmosphere.

Here we stand on the surface of an Earth-like world locked in a global ice age. Even the life giving oceans have frozen.

A vista from Frank Herbert's desert world Arrakis, also known as Dune. On Arrakis the only refuge from the consuming desert are the rare islands of stone.

From the icy surface of Europa, the sun comes out from behind Jupiter.

The first brown dwarf to be discovered and directly observed, Gliese 229 B emits far more heat than it receives from its distant red dwarf companion.

The planet of 16 Cygni B has an eccentric orbit which takes it as close to its sun as Venus and as far as Mars, passing through the habitable zone allowing liquid water to exist. Here we see an Earth-like moon during the habitable spring.

The second "Hot Jupiter" to be discovered, the planet orbiting 55 Cancri, like its cousin 51 Pegasi B, is awash in the glare of its nearby sun. On the night side of this seething world, we see super bolts of lightning arcing through the tumultuous atmosphere.

The planet orbiting 47 Ursae Majoris is close enough to its sun for liquid water to exist on its moons. Here we see a moon slightly smaller than Mars covered in glaciers. Under the frozen surface, a deep ocean of liquid water, and perhaps life, may reside.

The largest planet of PSR 1257+12 looms in the feeble light of its parent pulsar.