Nuevas evidencias de enormes masas de agua en Marte

La NASA descubre una nueva serie de depósitos sedimentarios en ‘Hellas Planitia’, un cráter localizado en el hemisferio sur marciano

La NASA ha descubierto nuevas evidencias de que Marte estuvo cubierto en gran parte por enormes océanos, de acuerdo con una serie de depósitos sedimentarios hallados en Hellas Planitia, un cráter localizado en el hemisferio sur marciano, según ha informado Instituto de Ciencias Planetarias de la agencia norteamericana del espacio.

Estos depósitos han podido observarse en los bordes de Hellas, una cuenca de unos 2. 000 kilómetros y ocho de profundidad, que es conocida como el mayor cráter de Marte. “Estos lagos existieron en Marte hace millones de años”, apunta Leslie Bleamaster, responsable del estudio.

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En concreto, estas evidencias forman parte de una investigación dedicada a configurar un mapa sobre la superficie de Marte por parte de los expertos del programa de Geología y Geofísica Planetaria de la NASA, con el objetivo de estudiar nuevas pistas sobre los patrones climáticos del planeta rojo, así como la historia de su superficie.

Asimismo, esta zona del planeta marciano se caracteriza por haber registrado actividad volcánica y sedimentaria a lo largo de la historia del planeta. Imágenes en alta resolución del Sistema de Imágenes de Emisión Termal (THEMIS) o de la Mars Orbiter Camera han participado en este programa de Geología y Geofísica Planetaria de la NASA.

www.publico.es

Como viene siendo habitual aprovechamos el post para dar un repaso a las ultimas noticias y videos de los diferentes eventos y misiones de las agencias espaciales internacionales. NASA, ESA, JAXA….etc

What’s Up June – A Planetary Necklace

This month you can view a planetary necklace spanning the sky from dusk to dawn.

 

Cuerpo luminoso impacta sobre Júpiter

Dos astrónomos aficionados, ubicados en dos lugares distintos del planeta, captaron el impacto de un cuerpo luminoso en la superficie del planeta Júpiter.

A Super Jupiter Makes its Mark

This ESOCast video shows how astronomers, for the first time, were able to directly follow the motion of an exoplanet as it moves from one side of its host star to the other. The planet has the smallest orbit so far of all directly imaged exoplanets, lying almost as close to its parent star as Saturn is to the Sun. Scientists believe that it may have formed in a similar way to the giant planets in the Solar System. Because the star is so young, this discovery proves that gas giant planets can form within discs in only a few million years, a short time in cosmic terms.

Only 12 million years old, or less than three-thousandths of the age of the Sun, Beta Pictoris is 75% more massive than our parent star. It is located about 60 light-years away towards the constellation of Pictor (the Painter) and is one of the best-known examples of a star surrounded by a dusty debris disc [1].

Earlier observations showed a warp of the disc, a secondary inclined disc and comets falling onto the star. “Those were indirect, but tell-tale signs that strongly suggested the presence of a massive planet, and our new observations now definitively prove this,” says team leader Anne-Marie Lagrange. “Because the star is so young, our results prove that giant planets can form in discs in time-spans as short as a few million years.” Recent observations have shown that discs around young stars disperse within a few million years, and that giant planet formation must occur faster than previously thought. Beta Pictoris is now clear proof that this is indeed possible.

The team used the NAOS-CONICA instrument (or NACO [2]), mounted on one of the 8.2-meter Unit Telescopes of ESO’s Very Large Telescope (VLT), to study the immediate surroundings of Beta Pictoris in 2003, 2008 and 2009. In 2003 a faint source inside the disc was seen (eso0842), but it was not possible to exclude the remote possibility that it was a background star. In new images taken in 2008 and spring 2009 the source had disappeared!

The most recent observations, taken during autumn 2009, revealed the object on the other side of the disc after a period of hiding either behind or in front of the star (in which case it is hidden in the glare of the star). This confirmed that the source indeed was an exoplanet and that it was orbiting its host star. It also provided insights into the size of its orbit around the star.

The planet has a mass of about nine Jupiter masses and the right mass and location to explain the observed warp in the inner parts of the disc. “Together with the planets found around the young, massive stars Fomalhaut and HR8799, the existence of Beta Pictoris b suggests that super-Jupiters could be frequent byproducts of planet formation around more massive stars,” explains Gael Chauvin, a member of the team.

Exoplanet Caught On The Move (For The First Time)

ESOcast 18: Exoplanet Caught on the Move (release date: Jun 10, 2010)

For the first time, astronomers have been able to directly follow the motion of an extrasolar planet as it moves from one side of its host star to the other. The alien world has the smallest orbit so far of all directly imaged exoplanets, lying almost as close to its parent star as Saturn is to the Sun. Scientists believe that it may have formed in a similar way to the giant planets in the Solar System. Because the star is so young, this discovery proves that gas giant planets can form within discs in only a few million years, a short time in cosmic terms.

Only 12 million years old, or less than three-thousandths of the age of the Sun, Beta Pictoris is 75% more massive than our parent star. It is located about 60 light-years away towards the constellation of Pictor (the Painter) and is one of the best-known examples of a star surrounded by a dusty debris disc.

Earlier observations showed a warp of the disc, a secondary inclined disc and comets falling onto the star. “Those were indirect, but tell-tale signs that strongly suggested the presence of a massive planet, and our new observations now definitively prove this,” says team leader Anne-Marie Lagrange. “Because the star is so young, our results prove that giant planets can form in discs in time-spans as short as a few million years.”

Recent observations have shown that discs around young stars disperse within a few million years, and that giant planet formation must occur faster than previously thought. Beta Pictoris is now clear proof that this is indeed possible.

The team used the NAOS-CONICA instrument (or NACO), mounted on one of the 8.2-metre Unit Telescopes of ESO’s Very Large Telescope (VLT), to study the immediate surroundings of Beta Pictoris in 2003, 2008 and 2009. In 2003 a faint source inside the disc was seen (eso0842), but it was not possible to exclude the remote possibility that it was a background star. In new images taken in 2008 and spring 2009 the source had disappeared!

The most recent observations, taken during autumn 2009, revealed the object on the other side of the disc after a period of hiding either behind or in front of the star (in which case it is hidden in the glare of the star). This confirmed that the source indeed was an exoplanet and that it was orbiting its host star. It also provided insights into the size of its orbit around the star.

The planet has a mass of about nine Jupiter masses and the right mass and location to explain the observed warp in the inner parts of the disc. This discovery therefore bears some similarity to the prediction of the existence of Neptune by astronomers Adams and Le Verrier in the 19th century, based on observations of the orbit of Uranus.

Such planets disturb the discs around their stars, creating structures that should be readily observable with the Atacama Large Millimeter/submillimeter Array (ALMA), the revolutionary telescope being built by ESO together with international partners.

A few other planetary candidates have been imaged, but they are all located further from their host star than Beta Pictoris b. If located in the Solar System, they all would lie close to or beyond the orbit of the furthest planet, Neptune. The formation processes of these distant planets are likely to be quite different from those in our Solar System and in Beta Pictoris.

http://www.eso.org/public/news/eso1024/
http://www.eso.org/public/archives/releases/sciencepapers/eso1024/eso1024.pdf
http://www.eso.org/public/outreach/products/press-kits/pdf/exoplanet_lowres.pdf

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