Jupiter as seen from Ganymede
Digital work
Good morning, Mars
Digital work
On Earth the molecules of the gases in the atmosphere scatter the blue light, this phenomenon is called Rayleigh Scattering. At sunrise and sunset direct sunlight crosses the maximum atmospheric thickness and reaches us so impoverished in short wavelengths that we see the solar disk and the nearby sky red or orange. But most of our sky stays blue all day long.
On Mars things are a little different. Its atmosphere has only 1% of the Earth's atmosphere density and the amount of Rayleigh scattering is much less. The daytime sky of Mars would be rather black, like that on the Moon. But Martian dust forms an aerosol that disperses long wavelengths by Mie scattering, because dust particles are much larger than gas molecules, and absorbs blue light. This is why the Martian sky during most of the day is yellowish or reddish brown. Part of the blue light is also scattered, but at very slight angles. Therefore the blue light is deflected less than longer wavelengths. At sunrise and sunset, when the Sun is seen through the maximum thickness of the dusty Martian atmosphere, the amount of Mie scattering is amplified and this gives Mars a brief blue moment, a beautiful aureole of scattered blue light surrounding the solar disk.
Buenos días, Marte. Obra digital.
Un día marciano tiene una duración casi idéntica a la de un día en la Tierra: 24,5 horas. El sol sale por el este y se pone por el oeste, como en nuestro planeta. Pero hay una gran diferencia: en Marte los amaneceres y atardeceres son azules.
En la Tierra las moléculas de los gases de la atmósfera dispersan la luz azul, fenómeno denominado Dispersión de Rayleigh. En los amaneceres y atardeceres la luz solar directa atraviesa el máximo grosor atmosférico y llega hasta nosotros tan empobrecida en longitudes de onda corta que vemos el disco solar y el cielo próximo de color rojo o anaranjado. Pero la mayor parte de nuestro cielo se mantiene azul durante todo el día.
En Marte las cosas son un poco distintas. Su atmósfera tiene sólo el 1% de la densidad de la atmósfera terrestre y el efecto debido a la dispersión de Rayleigh es mucho menor. El cielo diurno de Marte bien podría ser negro como el de la Luna. Pero el polvo marciano en suspensión, que se encuentra en grandes cantidades formando un aerosol, dispersa las longitudes de onda larga siguiendo el modelo de la Difusión de Mie, al tener las partículas de polvo un tamaño mucho mayor que las moléculas de los gases, y a su vez absorbe la luz azul. Este es el motivo por el que el cielo de Marte es marrón rojizo o amarillento durante la mayor parte del día. Parte de la luz azul es dispersada también, pero en un ángulo muy pequeño, lo que hace que sea desviada mucho menos del haz de luz incidente. En el amanecer y el atardecer, cuando el Sol es visto a través del máximo grosor de la polvorienta atmósfera marciana, el efecto de la difusión de Mie se ve amplificado y esto regala a Marte un breve momento azul, una hermosa aureola de luz azul dispersada alrededor del disco solar.
Ocean Planet
Digital work
An ocean planet not only has its entire surface covered by water; much of its mass and volume is water. Our planet, Earth, has 71% of its surface covered by oceans. But water represents only 0.05% of the planetary mass. We live on a rocky planet with a thin ocean that has a maximum depth of just over 10 kilometers. On an ocean planet the depths are abysmal, hundreds or even thousands of kilometers. At the bottom the water is so compressed that it solidifies and crystallizes, forming exotic species of ice, such as ice VII.
In this artwork we can see an ocean planet with a large extrasolar moon. The atmosphere is dense and saturated with water vapor and there is a persistent mist on the surface of the sea. All this causes an important greenhouse effect.
Planeta Océano. Obra digital.
Un planeta océano no sólo tiene toda su superficie cubierta por agua. Además, gran parte de su masa y su volumen es agua. Nuestro planeta, la Tierra, tiene el 71 % de su superficie cubierta por océanos. Pero el agua representa tan sólo el 0,05% de la masa planetaria. Vivimos en un planeta rocoso con un delgado océano que tiene una profundidad máxima de poco más de 10 kilómetros. En un planeta océano las profundidades son abismales, de cientos o incluso miles de kilómetros. En el fondo el agua está tan comprimida que se solidifica y cristaliza, formándose especies exóticas de hielo, como el hielo VII.
En la ilustración vemos un planeta océano con una gran luna extrasolar. La atmósfera es densa y saturada de vapor de agua y hay una niebla persistente sobre la superficie del mar. Todo ello provoca un importante efecto invernadero.
Saturn Blues
Digital work
In 2005 the Cassini spacecraft confirmed what we already assumed: Saturn's sky above its thick clouds is blue. As blue as Earth's sky. Rayleigh scattering occurs when light passes through a transparent medium consisting of particles whose size is much smaller than the wavelength of the scattered photons. The amount of scattering is inversely proportional to the wavelength of the light, so it affects mainly the short wavelengths: The blue light is much more scattered than the yellow light or the red light. The atmosphere of Saturn is made up of hydrogen, while on Earth it is nitrogen and oxygen. But the physical principle occurs equally in both cases. Other places in the Solar System with blue skies are Jupiter, Uranus, Neptune, Titan (above the layer of hydrocarbon haze) and Pluto. Surely the Universe is full of billions of worlds with blue skies ...
Blues de Saturno. Obra digital.
En 2005 la nave Cassini confirmó lo que ya suponíamos: El cielo de Saturno por encima de sus gruesas nubes es azul. Tan azul como el cielo de la Tierra. La dispersión de Rayleigh se produce cuando la luz atraviesa un medio transparente constituido por partículas cuyo tamaño es muy inferior a la longitud de onda de los fotones dispersados. El grado de dispersión o esparcimiento es inversamente proporcional a la longitud de la onda lumínica, por lo que afecta mayoritariamente a las longitudes de onda corta: La luz azul es dispersada mucho más que la luz amarilla o la roja. La atmósfera de Saturno está constituida por hidrógeno, mientras que en la Tierra es nitrógeno y oxígeno. Pero el principio físico se produce de igual modo en ambos casos. Otros lugares del Sistema Solar con cielos azules son Júpiter, Urano, Neptuno, Titán (por encima de la capa de neblina de hidrocarburos) y Plutón. Seguramente el Universo está lleno de miles de millones de mundos con cielos azules...
Under the light of three suns
Digital work
Gliese 667 is a triple-star system located about 24 light years from us. Orbiting within the habitable zone of one of them, the red dwarf Gliese 667C, is the planet Gliese 667Cc, a super-Earth with a mass 3.8 times greater than that of the Earth. It is probably a rocky planet that could also have oceans and atmosphere. In the sky its mother star shines with an intense reddish light and has a splendid apparent size of 1.25º, almost two and a half times the Sun seen from Earth. The other two stars of the system, Gliese 667A and Gliese 667B are K-type main-sequence stars and their powerful brightness are always visible.
Bajo la luz de tres soles. Obra digital.
Gliese 667 es un sistema triple de estrellas situado a unos 24 años luz de nosotros. Orbitando dentro de la zona de habitabilidad de una de ellas, la enana roja Gliese 667C, se halla el planeta Gliese 667Cc, una supertierra con una masa 3,8 veces mayor que la de la Tierra. Es probablemente un planeta rocoso que podría tener también océanos y atmósfera. En el cielo su estrella madre brilla con una intensa luz rojiza y tiene un espléndido tamaño aparente de 1,25º, casi dos veces y media el Sol visto desde la Tierra. Las otras dos estrellas del sistema, Gliese 667A y Gliese 667B son enanas naranjas de tipo espectral K y sus potentes destellos son siempre visibles.
Children of a minor Sun
Digital work
This is my first approach to the field of extrasolar planets.
Of the 7 planets forming the TRAPPIST-1 system, it may be TRAPPIST-1e that has Earth-like environmental conditions: water oceans, emerged lands, atmosphere and temperatures compatible with life. But like its companions, this planet is tidally locked, so the conditions previously described would only be found on the side that always looks at its star, TRAPPIST-1, a red ultracool dwarf star (M type) with a size slightly larger than the planet Jupiter. Here everything is illuminated by an exclusively red or orange light. At the same time the dark side of the planet will probably be a frozen world with a perpetual night.
Hijos de un Sol menor. Obra digital
Esta es mi primera aproximación al tema de los planetas extrasolares.
De los siete planetas que componen el sistema TRAPPIST-1, tal vez sea TRAPPIST-1e el que reúna unas condiciones ambientales más parecidas a la Tierra: Océanos de agua, tierras emergidas, atmósfera y temperaturas compatibles con la vida. Pero al igual que sus compañeros, el planeta presenta acoplamiento de marea por lo que las condiciones descritas sólo se darían en la cara que mira a su estrella, TRAPPIST-1, una enana roja ultrafría (de tipo espectral M), con un tamaño algo superior al de Júpiter. Su luz ilumina de un rojo anaranjado intenso el cielo y el paisaje del planeta, mientras que en el lado oscuro reina una noche perpetua sobre un mundo congelado.
Lonely Sedna
Digital work
A sunny day on Sedna, as shown in this picture. The focus of light in the sky is not only the Sun, but the whole Solar System including the cloud of interplanetary dust that causes the zodiacal light.
Sedna (or 90377 Sedna) is a large minor planet in the outer reaches of the Solar System. With its aphelion estimated at 937 AU (about 31 times the distance of Neptune), it is one of the most distant known objects in the Solar System, other than long-period comets. It has an exceptionally long and elongated orbit, taking approximately 11,400 years to complete. Many astronomers conclude that Sedna is the first known member of the inner Oort Cloud.
Spectroscopy has revealed that Sedna's surface composition is similar to that of some other trans-Neptunian objects, being largely a mixture of water, methane and nitrogen ices with tholins. Its surface is one of the reddest among Solar System objects.
Sedna, the Inuit goddess of the sea, who is thought to live at the bottom of the frigid Arctic Ocean...
Sedna solitario. Obra digital.
Un día soleado en Sedna, tal y como se muestra en la imagen. El foco de luz visible en el cielo no es sólo el Sol, sino la totalidad del Sistema Solar incluyendo la nube de polvo interplanetario que origina la luz zodiacal.
Sedna (o 90377 Sedna) es un gran cuerpo menor en las fronteras del Sistema Solar. Con un afelio estimado en 937 UA (unas 31 veces la distancia a Neptuno) es uno de los objetos más distantes del Sistema Solar, aparte de los cometas de período largo. Tiene una órbita excepcionalmete larga y elongada que tarda unos 11.400 años en completar. Muchos astrónomos afirman que Sedna es el primer miembro conocido de la Nube de Oort interior. La espectroscopía ha revelado que la composición de la superficie de Sedna es similar a la de otros objetos trans-neptunianos, estando básicamente constituida por una mezcla de hielo de agua, metano y nitrógeno con tolinas de hidrocarburos. Es una de las más rojas del Sistema Solar. Sedna, la diosa inuit del mar, que tiene su morada en las profundidades del gélido océano Ártico...
A serene night on Europa
Digital work
The Sun is situated below the horizon and the only sources of light that illuminate the smooth and white surface of Europa at this time are Jupiter and Io. The light appears to be somewhat bluish to the human eye, as it happens here on Earth with the moonlight, due to the Purkinje effect: When the luminance level is reduced, our vision changes progressively from photopic (cone cells, full color) to mesopic and finally scotopic (rod cells, black and white) and the last colors we perceive are those of short wavelength. The surface of Europa is very reflective. It has an albedo of 0.64, one of the highest in the Solar System.
Una noche serena en Europa. Obra digital.
El Sol está situado por debajo del horizonte y las únicas fuentes de luz que iluminan ahora la suave y blanca superficie de Europa son Júpiter e Io. La tenue luz del paisaje aparenta ser un tanto azulada al ojo humano, tal y como sucede aquí en la Tierra con la luz de la Luna. Es debido al efecto Purkinje: Cuando el nivel de luminancia disminuye nuestro modo de visión pasa progresivamente de fotópico (visión a todo color por conos) a mesópico y finalmente escotópico (visión por bastoncillos en blanco y negro). Los últimos colores que percibimos son los de longitud de onda corta.
La superficie de Europa es muy reflectante. Tiene un albedo de 0.64, uno de los más altos del Sistema Solar.
Dust storm on Mars
Digital work
Mars has intense dust storms, which sometimes kick up enough dust to be seen by telescopes on Earth. Every year there are some moderately big dust storms that pop up on Mars and they cover continent-sized areas and last for weeks. Once every three Mars years (about 5.5 Earth years), on average, normal storms grow into planet-encircling dust storms, called "global dust storms".
It is unlikely that even these dust storms could strand an astronaut on Mars, however. Even the wind in the largest storms likely could not tip or rip apart major mechanical equipment. The winds in the strongest Martian storms top out at about 100 km (60 miles) per hour, less than half the speed of some hurricane-force winds on Earth. But the atmosphere of Mars is only about 1% as dense as Earth's atmosphere. That means to fly a kite on Mars, the wind would need to blow much faster than on Earth to get the kite in the air.
And Mars got its ring...
Digital work
This is my personal view of the future Martian ring. This image would fit well on a dusty dawn at a latitude of about 20ºN during a Martian equinox.
Phobos is moving closer to Mars every year, meaning the planet's gravitional pull on the satellite is increasing. Some scientists have theorized that Phobos will eventually collide with Mars, but the new research suggests that the small moon may not last that long. After simulating the stresses caused by the tidal pull of Mars some researchers have found that the moon would break up over the course of 20 million to 40 million years, forming a ring of debris around the planet. WOW!
Earth as seen from Mars
Digital work
Based on the images taken by Mars Curiosity Rover on January 31, 2014. From Mars our planet is a bright morning or evening "star", it appears in the west after sunset or in the east before dawn. Very similar to Venus in our sky with a magnitude of -2,5.
La Tierra vista desde Marte. Obra digital.
Ilustración inspirada en las imágenes tomadas por el Mars Curiosity Rover el 31 de enero de 2014. Desde Marte nuestro planeta es como una brillante estrella del crepúsculo matutino o vespertino, aparece en el oeste tras la puesta de Sol o en el este antes del amanecer. Muy similar a Venus en nuestro cielo, con una magnitud de -2,5.
Mars as seen from Phobos
Digital work
Separated by a short distance of 9,380 kilometers, from Phobos Mars is immense. The angular size of 40º is 80 times our Moon as seen from Earth.
Marte visto desde Fobos. Obra digital.
Separados por la corta distancia de 9.380 kilómetros, desde Fobos Marte se ve inmenso. Con un tamaño angular de 40º es 80 veces nuestra Luna vista desde la Tierra.
Phobos and Deimos in the sky of Mars
Digital work
Phobos moves very quickly in the sky of Mars. From its dawn in the west to its setting in the east, the satellite crosses the Martian sky in only 4 hours and 15 minutes. The angular size is about 0.20 °, one-third the size of the Moon in our sky. Deimos is visible with a size of 2.5 arcminutes, similar to Venus seen from Earth.
Callisto
Digital work
The ancient surface of Callisto is one of the most heavily cratered in the Solar System. A surface made of cratered plains, light plains, bright and dark smooth plains... a contrast of darkness and brightness. Callisto also hides a treasure: A salty ocean 50-200 km deep beneath its surface. Callisto's surface has an averige albedo of about 20%, but small patches of pure water ice, water frost deposits, with an albedo as high as 80% are found on the surface, surrounded by much darker areas. They are located on elevated surface features as crater rims, scarps and ridges.
In the sky, Jupiter with a size of 4º, eight times our Moon seen from Earth. Here it is accompanied by one of its inner moons, Europa.
The colossal fountains of Enceladus
Digital work
Huge jets of water ice that rise thousands of kilometers above the surface. Undoubtedly, one of the greatest wonders of the Solar System.
The powerful gravitational force of Saturn heats the interior of the small moon, making possible the existence of an inner ocean of liquid water. When the water is expelled to the outside, when it contacts the space vacuum it vaporizes and explodes, forming the geysers. Immediately the vapor is frozen again, falling in the form of snowflakes.
Las fuentes colosales de Encélado. Obra digital.
Enormes chorros de hielo de agua que se elevan a miles de kilómetros sobre la superficie. Indudablemente, una de las maravillas más grandes del Sistema Solar.
La poderosa fuerza gravitacional de Saturno calienta el interior de la pequeña luna permitiendo la existencia de un océano interior de agua líquida. Cuando este agua es expulsada al exterior, al contactar con el vacío no presurizado del espacio, estalla violentamente y se transforma en vapor formando géiseres. Casi inmediatamente este vapor se vuelve a congelar y cae en forma de copos de nieve.
Charon from Pluto
Digital work
In 1988 the atmosphere of Pluto was detected for the first time during a stellar occultation. New Horizons spacecraft arrived at Pluto in July 2015. It found a surprisingly robust hazy atmosphere on the dwarf planet. The haze extends at least 160 kilometers (100 miles) above the surface. Clouds, haze, winds, micro snowflakes,... could all be part of Pluto's dynamic weather system. Clouds and haze must be made of the very constituents of its atmosphere: molecular nitrogen and some carbon monoxide and methane. The presence of clouds, however, is dependent on the existence of a temperature gradient, like that on Earth. And with clouds must come some form of rain or, at Pluto's distance from the Sun, snow. It is thought that clouds in Pluto's atmosphere may be composed of tiny frozen spherules of nitrogen or carbon monoxide, rather than liquid or snowflakes.
Charon, the faithful companion, is seen in Pluto's sky with a size of 3º, six times our Moon from Earth.
The frozen plains of Pluto
Digital work
Although the apparent size of the Sun is 30 times smaller than seen from Earth, from Pluto our star is still very bright, giving roughly 150 to 450 times the light of the full Moon on Earth (the variability being due to the fact that Pluto's orbit is highly elliptical). So it is still possible to read a book on Pluto. Pluto's atmosphere consists of a thin envelope of nitrogen, methane and carbon monoxide gases, which are derived from the ices of these substances on its surface, This atmosphere produces a noticeable blue haze which is visible at sunset.
Storm on Titan
Digital work
Dense clouds of methane that cause violent storms often occur on the largest moon of Saturn, Titan. And most likely we will find other meteorological phenomena, such as heavy rains of liquid methane (whose drops must be larger than those of rainwater on Earth), lightning and thunder and the rainbow ...
Tvashtar erupting, Io
Digital work
Digital work
The Galileo spacecraft was able to study huge eruptions on Tvashtar Paterae: A 25-kilometer long (16 mi), 1 to 2-kilometer high (0.62 to 1.24 mi) curtain of lava was seen, followed by a plume of gas rising 385 kilometers (239 mi) above the surface of Io. On February 2007 the New Horizons probe, on its way to Pluto, captured an enormous eruption with a 330-kilometer high (210 mi) plume.
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