Source: SPACE.com: All about our solar system, outer space and exploration
viernes, 21 de octubre de 2011
A New Assessment of Global Warming
The most important indicator of global warming, by far, is the land and sea surface temperature record. This has been criticized in several ways, including the choice of stations and the methods for correcting systematic errors. The Berkeley Earth Surface Temperature study sets out to to do a new analysis of the surface temperature record in a rigorous manner that addresses this criticism. We are using over 39,000 unique stations, which is more than five times the 7,280 stations found in the Global Historical Climatology Network Monthly data set (GHCN-M) that has served as the focus of many climate studies.
Our aim is to resolve current criticism of the former temperature analyses, and to prepare an open record that will allow rapid response to further criticism or suggestions. Our results include not only our best estimate for the global temperature change, but estimates of the uncertainties in the record.
Our aim is to resolve current criticism of the former temperature analyses, and to prepare an open record that will allow rapid response to further criticism or suggestions. Our results include not only our best estimate for the global temperature change, but estimates of the uncertainties in the record.
he Berkeley Earth Surface Temperature Study has created a preliminary merged data set by combining 1.6 billion temperature reports from 15 preexisting data archives. Whenever possible, we have used raw data rather than previously homogenized or edited data. After eliminating duplicate records, the current archive contains 39,390 unique stations. This is more than five times the 7,280 stations found in the Global Historical Climatology Network Monthly data set (GHCN-M) that has served as the focus of many climate studies. The GHCN-M is limited by strict requirements for record length, completeness, and the need for nearly complete reference intervals used to define baselines. We have developed new algorithms that reduce the need to impose these requirements (see methodology), and as such we have intentionally created a more expansive data set.
We performed a series of tests to identify dubious data and merge identical data coming from multiple archives. In general, our process was to flag dubious data rather than simply eliminating it. Flagged values were generally excluded from further analysis, but their content is preserved for future consideration.
Specifically, the Berkeley Earth study concludes that:
•The urban heat island effect is locally large and real, but does not contribute significantly to the average land temperature rise. That's because the urban regions of Earth amount to less than 1% of the land area.
•About 1/3 of temperature sites around the world reported global cooling over the past 70 years (including much of the United States and northern Europe). But 2/3 of the sites show warming. Individual temperature histories reported from a single location are frequently noisy and/or unreliable, and it is always necessary to compare and combine many records to understand the true pattern of global warming.
•The large number of sites reporting cooling might help explain some of the skepticism of global warming," Rohde commented. "Global warming is too slow for humans to feel directly, and if your local weather man tells you that temperatures are the same or cooler than they were a hundred years ago it is easy to believe him." In fact, it is very hard to measure weather consistently over decades and centuries, and the presence of sites reporting cooling is a symptom of the noise and local variations that can creep in. A good determination of the rise in global land temperatures can't be done with just a few stations: it takes hundreds -- or better, thousands -- of stations to detect and measure the average warming. Only when many nearby thermometers reproduce the same patterns can we know that the measurements were reliably made.
•Stations ranked as "poor" in a survey by Anthony Watts and his team of the most important temperature recording stations in the U.S., (known as the USHCN -- the US Historical Climatology Network), showed the same pattern of global warming as stations ranked "OK." Absolute temperatures of poor stations may be higher and less accurate, but the overall global warming trend is the same, and the Berkeley Earth analysis concludes that there is not any undue bias from including poor stations in the survey.
Specifically, the Berkeley Earth study concludes that:
•The urban heat island effect is locally large and real, but does not contribute significantly to the average land temperature rise. That's because the urban regions of Earth amount to less than 1% of the land area.
•About 1/3 of temperature sites around the world reported global cooling over the past 70 years (including much of the United States and northern Europe). But 2/3 of the sites show warming. Individual temperature histories reported from a single location are frequently noisy and/or unreliable, and it is always necessary to compare and combine many records to understand the true pattern of global warming.
•The large number of sites reporting cooling might help explain some of the skepticism of global warming," Rohde commented. "Global warming is too slow for humans to feel directly, and if your local weather man tells you that temperatures are the same or cooler than they were a hundred years ago it is easy to believe him." In fact, it is very hard to measure weather consistently over decades and centuries, and the presence of sites reporting cooling is a symptom of the noise and local variations that can creep in. A good determination of the rise in global land temperatures can't be done with just a few stations: it takes hundreds -- or better, thousands -- of stations to detect and measure the average warming. Only when many nearby thermometers reproduce the same patterns can we know that the measurements were reliably made.
•Stations ranked as "poor" in a survey by Anthony Watts and his team of the most important temperature recording stations in the U.S., (known as the USHCN -- the US Historical Climatology Network), showed the same pattern of global warming as stations ranked "OK." Absolute temperatures of poor stations may be higher and less accurate, but the overall global warming trend is the same, and the Berkeley Earth analysis concludes that there is not any undue bias from including poor stations in the survey.
We filtered and merged the data archives using the following steps:
1- Duplicate filter: We first separately searched each archive for multiple copies of the same record and eliminated the duplicates.
2- Data split: Each unique record was broken up into fragments having no gaps longer than 1 year. Each fragment was then treated as a separate record for filtering and merging. Note however that the number of stations is based on the number of unique locations, and not the number of record fragments.
3- Bad values filter: We flagged and excluded from further study values that had pre-existing indicators of data quality problems associated with instrumental error, in-filling of missing data, and/or post-hoc manipulations. We further removed values that exceeded global climate extremes (e.g. +5000 F).
4- Repetition filter: We tested for runs of repeated values, a common sign of in-filling missing days, and flagged repeated values exceeding an empirical 99.9% threshold for non-randomness.
5- Local outlier filter: We tested for and flagged values that exceeded a locally determined empirical 99.9% threshold for normal climate variation in each record.
6- Temperature consistency filter: We required that the minimum temperature (Tmin) be strictly less than the maximum temperature (Tmax) for each measurement. We further required that any reported average or instantaneous temperature (Tavg and Tobs) be between the reported max and min, inclusive.
7- Initial merge: Using nearby locations and matching station ID codes, we tested for the presence of identical data in multiple archives. Records that had identical content for at least 90% of values were then merged. Small segments of non-identical content within otherwise equivalent records were flagged and also carried forward.
8- Regional filter: For each record, the 21 nearest neighbors having at least 5 years of record were located. These were used to estimate a normal pattern of seasonal climate variation. After adjusting for changes in latitude and altitude, each record was compared to its local normal pattern and 99.9% outliers were flagged. Simultaneously, a test was conducted to detect long runs of data that had apparently been miscoded as Fahrenheit when reporting Celsius. Such values, which might include entire records, would be expected to match regional norms after the appropriate unit conversion but not before.
9-Second merge: Monthly time series were constructed from daily values with both a version using all values and a version using only non-flagged values. These monthly synthesis records were then compared to the values in data archives that reported only monthly data. Duplicates were found as before and merged.
9-Second merge: Monthly time series were constructed from daily values with both a version using all values and a version using only non-flagged values. These monthly synthesis records were then compared to the values in data archives that reported only monthly data. Duplicates were found as before and merged.
10- Site reduction: Though a majority of all station repetitions are identified by the presence of duplicated data, in a significant number of cases the presence of pre-existing data manipulations inhibited our tests for data duplication. We designed several tests based on location, name, and id codes to identify matching sites with somewhat dissimilar data. These were then consolidated as single stations having multiple data series.
11- Best value series: “Best value” time series were formed by averaging across multiple records when they existed at the same site. In addition, flagged values were dropped and previously manipulated GHCN-M and Hadley Centre data was ignored in favor of other data sources when possible. These series are expected to the primary records for most future studies, but the fully-flagged and multi-valued records will also be preserved and made available for more detailed analyses.
12- Seasonality removed series: Finally, non-seasonal series were created by determining the mean seasonal cycle at each location and subtracting this from the best value data.
We are currently preparing a detailed write up of the process used for the data filtering and merge.
We are currently preparing a detailed write up of the process used for the data filtering and merge.
 |
| The following chart shows the annual land-surface average temperature using a 12 month moving average of surface temperatures over land. Anomalies are relative to the Jan 1950 - December 1979 mean. The grey band indicates 95% statistical and spatial uncertainty interval. |
 |
| The following chart shows the decadal land-surface average temperature using a 10-year moving average of surface temperatures over land. Anomalies are relative to the Jan 1950 - December 1979 mean. The grey band indicates 95% statistical and spatial uncertainty interval. |
| Berkeley Earth Data |
| The Berkeley Earth merged data set can be accessed from the links below. |
| Berkeley Earth Analysis Code |
| The Berkeley Earth analysis code is available from the link below. |
|
martes, 18 de octubre de 2011
¿Y de dónde vino tanta agua?
 |
| Using the Herschel Space Observatory, astronomers have discovered that comet Hartley 2 possesses a ratio of "heavy water" to light, or normal, water that matches what's found in Earth's oceans. Image credit: NASA/JPL-Caltech |
Nuevas mediciones del Observatorio Espacial Herschel muestran que el cometa Hartley 2, que viene del lejano Cinturón de Kuiper, contiene agua con la misma firma química como los océanos de la Tierra. Esta remota región del sistema solar, unos 30 a 50 veces más lejos que la distancia entre la Tierra y el Sol, es el hogar de los cuerpos helados y rocosos incluyendo a Plutón, los planetas enanos y otras innumerables cometas.
"Nuestros resultados con Herschel sugieren que los cometas podrían haber jugado un papel importante en traer grandes cantidades de agua a una Tierra primitiva", dijo Dariusz Lis, asociada principal de investigación en física en el Instituto de Tecnología de California en Pasadena y co-autor de un nuevo trabajo publicado en la revista Nature, publicado en línea el 05 de octubre pasado. "This finding substantially expands the reservoir of Earth ocean-like water in the solar system to now include icy bodies originating in the Kuiper Belt."
 |
The Same Here as ThereNew measurements from the Herschel Space Observatory have discovered water with the same chemical signature as our oceans in a comet called Hartley 2 (pictured at right). Previously, astronomers thought icy comets impacting on a young Earth had deposited only about 10 percent of the water comprising our oceans. The new findings, however, suggest that comets played a much bigger role. The image of comet Harley 2 at top right was taken by NASA's EPOXI mission. The image at bottom right is an artist's concept of a comet. |
Los científicos teorizan que la Tierra empezó caliente y seca, por lo que el agua, esencial para la vida, debe haber llegado millones de años más tarde por impactos de asteroides y cometas. Hasta ahora, ninguno de los cometas estudiado previamente había mostrado agua como la contenida en la Tierra. Sin embargo, las observaciones de Herschel sobre el Hartley 2, abren un panorama diferente.
Herschel detected the signature of vaporized water in this coma and, to the surprise of the scientists, Hartley 2 possessed half as much "heavy water" as other comets analyzed to date. In heavy water, one of the two normal hydrogen atoms has been replaced by the heavy hydrogen isotope known as deuterium. The ratio between heavy water and light, or regular, water in Hartley 2 is the same as the water on Earth's surface. The amount of heavy water in a comet is related to the environment where the comet formed.
By tracking the path of Hartley 2 as it swoops into Earth's neighborhood in the inner solar system every six and a half years, astronomers know that it comes from the Kuiper Belt. The five comets besides Hartley 2 whose heavy-water-to-regular-water ratios have been obtained all come from an even more distant region in the solar system called the Oort Cloud. This swarm of bodies, 10,000 times farther afield than the Kuiper Belt, is the wellspring for most documented comets.
Given the higher ratios of heavy water seen in Oort Cloud comets compared to Earth's oceans, astronomers had concluded that the contribution by comets to Earth's total water volume stood at approximately 10 percent. Asteroids, which are found mostly in a band between Mars and Jupiter but occasionally stray into Earth's vicinity, looked like the major depositors. The new results, however, point to Kuiper Belt comets having performed a previously underappreciated service in bearing water to Earth.
How these objects ever came to possess the tell-tale oceanic water is puzzling. Astronomers had expected Kuiper Belt comets to have even more heavy water than Oort Cloud comets because the latter are thought to have formed closer to the sun than those in the Kuiper Belt. Therefore, Oort Cloud bodies should have had less frozen heavy water locked in them prior to their ejection to the fringes as the solar system evolved.
"Our study indicates that our understanding of the distribution of the lightest elements and their isotopes, as well as the dynamics of the early solar system, is incomplete," said co-author Geoffrey Blake, professor of planetary science and chemistry at Caltech. "In the early solar system, comets and asteroids must have been moving all over the place, and it appears that some of them crash-landed on our planet and made our oceans."
 | ||
|
Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes. NASA's Herschel Project Office is based at the agency's Jet Propulsion Laboratory in Pasadena, Calif., which contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at Caltech in Pasadena, supports the U.S. astronomical community.
New measurements from the Herschel Space Observatory have discovered water with the same chemical signature as our oceans in a comet called Hartley 2 (pictured at right). Image credit: NASA/JPL-Caltech Using the Herschel Space Observatory, astronomers have discovered that comet Hartley 2 possesses a ratio of "heavy water" to light, or normal, water that matches what's found in Earth's oceans. Image credit: NASA/JPL-Caltech
PASADENA, Calif. -- Astronomers have found a new cosmic source for the same kind of water that appeared on Earth billions of years ago and created the oceans. The findings may help explain how Earth's surface ended up covered in water.
New measurements from the Herschel Space Observatory show that comet Hartley 2, which comes from the distant Kuiper Belt, contains water with the same chemical signature as Earth's oceans. This remote region of the solar system, some 30 to 50 times as far away as the distance between Earth and the sun, is home to icy, rocky bodies including Pluto, other dwarf planets and innumerable comets.
"Our results with Herschel suggest that comets could have played a major role in bringing vast amounts of water to an early Earth," said Dariusz Lis, senior research associate in physics at the California Institute of Technology in Pasadena and co-author of a new paper in the journal Nature, published online today, Oct. 5. "This finding substantially expands the reservoir of Earth ocean-like water in the solar system to now include icy bodies originating in the Kuiper Belt."
Scientists theorize Earth started out hot and dry, so that water critical for life must have been delivered millions of years later by asteroid and comet impacts. Until now, none of the comets previously studied contained water like Earth's. However, Herschel's observations of Hartley 2, the first in-depth look at water in a comet from the Kuiper Belt, paint a different picture.
Herschel peered into the comet's coma, or thin, gaseous atmosphere. The coma develops as frozen materials inside a comet vaporize while on approach to the sun. This glowing envelope surrounds the comet's "icy dirtball"-like core and streams behind the object in a characteristic tail.
Herschel detected the signature of vaporized water in this coma and, to the surprise of the scientists, Hartley 2 possessed half as much "heavy water" as other comets analyzed to date. In heavy water, one of the two normal hydrogen atoms has been replaced by the heavy hydrogen isotope known as deuterium. The ratio between heavy water and light, or regular, water in Hartley 2 is the same as the water on Earth's surface. The amount of heavy water in a comet is related to the environment where the comet formed.
By tracking the path of Hartley 2 as it swoops into Earth's neighborhood in the inner solar system every six-and-a-`half years, astronomers know that it comes from the Kuiper Belt. The five comets besides Hartley 2 whose heavy-water-to-regular-water ratios have been obtained all come from an even more distant region in the solar system called the Oort Cloud. This swarm of bodies, 10,000 times farther afield than the Kuiper Belt, is the wellspring for most documented comets.
Given the higher ratios of heavy water seen in Oort Cloud comets compared to Earth's oceans, astronomers had concluded that the contribution by comets to Earth's total water volume stood at approximately 10 percent. Asteroids, which are found mostly in a band between Mars and Jupiter but occasionally stray into Earth's vicinity, looked like the major depositors. The new results, however, point to Kuiper Belt comets having performed a previously underappreciated service in bearing water to Earth.
How these objects ever came to possess the telltale oceanic water is puzzling. Astronomers had expected Kuiper Belt comets to have even more heavy water than Oort Cloud comets because the latter are thought to have formed closer to the sun than those in the Kuiper Belt. Therefore, Oort Cloud bodies should have had less frozen heavy water locked in them prior to their ejection to the fringes as the solar system evolved.
"Our study indicates that our understanding of the distribution of the lightest elements and their isotopes, as well as the dynamics of the early solar system, is incomplete," said co-author Geoffrey Blake, professor of planetary science and chemistry at Caltech. "In the early solar system, comets and asteroids must have been moving all over the place, and it appears that some of them crash-landed on our planet and made our oceans."
Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes. NASA's Herschel Project Office is based at the agency's Jet Propulsion Laboratory in Pasadena, Calif., which contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at Caltech in Pasadena, supports the U.S. astronomical community. Caltech manages JPL for NASA.
More information is online at http://www.herschel.caltech.edu, http://www.nasa.gov/herschel and http://www.esa.int/SPECIALS/Herschel/index.html .
lunes, 17 de octubre de 2011
Misión Kepler de la NASA descubre un mundo que orbita dos estrellas
La existencia de un mundo con una puesta de sol doble es ahora un hecho científico. La misión Kepler de la NASA ha realizado la primera detección inequívoca de un planeta circumbinary (circumbinary planet)- un planeta que orbita dos estrellas, a 200 años-luz de la Tierra. El planeta, Kepler 16b es frío, gaseoso. Kepler es la primera misión de la NASA capaz de encontrar planetas del tamaño de la Tierra en o cerca de la "zona habitable", la región en un sistema planetario en donde puede existir agua líquida en la superficie del planeta en órbita.
"This discovery confirms a new class of planetary systems that could harbor life," Kepler principal investigator William Borucki said. "Given that most stars in our galaxy are part of a binary system, this means the opportunities for life are much broader than if planets form only around single stars. This milestone discovery confirms a theory that scientists have had for decades but could not prove until now.
Scientists detected the new planet in the Kepler-16 system, a pair of orbiting stars that eclipse each other from our vantage point on Earth. When the smaller star partially blocks the larger star, a primary eclipse occurs, and a secondary eclipse occurs when the smaller star is occulted, or completely blocked, by the larger star.
Astronomers further observed that the brightness of the system dipped even when the stars were not eclipsing one another, hinting at a third body. The additional dimming in brightness events, called the tertiary and quaternary eclipses, reappeared at irregular intervals of time, indicating the stars were in different positions in their orbit each time the third body passed. This showed the third body was circling, not just one, but both stars, in a wide circumbinary orbit.
Key Kepler-16b Announcement Slides
- Eclipsing binary stars light curve
- Kepler-16 light curve
- Deviation of eclipse occurences
- Kepler-16 system overlaid on our inner solar system
Other Kepler Image and Video Resources
- Video: Kepler Field of View
- Video: Kepler Overview
- Video: Transit Light Curve
- For more Kepler images, visit http://kepler.nasa.gov/multimedia/.
- NASA image usage policy
Past Kepler Discoveries
- Jan. 4, 2010: NASA’s Kepler Space Telescope Discovers its First Five Exoplanets
- June 15, 2010: NASA Releases Kepler Data on Potential Extrasolar Planets
- Aug. 26, 2010: NASA's Kepler Mission Discovers Two Planets Transiting the Same Star
- Jan. 10, 2011: NASA'S Kepler Mission Discovers Its First Rocky Planet
- Feb. 2, 2011: NASA's Kepler Spacecraft Discovers Extraordinary New Planetary System
- Feb. 2, 2011: NASA Finds Earth-size Planet Candidates in the Habitable Zone
domingo, 9 de octubre de 2011
Vida en Marte: "un poco de buena voluntad"
“¡Ares, Ares, funesto a los mortales, manchado de homicidios, demoledor de murallas!… Funesto a los mortales, manchado de homicidios, demoledor de murallas!” (Homero, La Iliada)."Ivi con tutta serietà sono proposte ingenti somme come premio a chi sarà primo a dimostrare, per mezzo della diretta osservazione, che esistono in alcuno degli astri indizî certi di esseri intelligenti" (Giovanni Schiaparelli,La Vida en Marte, 1893).
Marte, el dios romano de la Guerra. Ares en la mitología griega. En la Ilíada, Homero lo describe como el “horrendo”, el “homicida”, el “luctuoso”, “infatigable luchador”, “feroz”, el del “terror”,“furibundo”,“impetuoso”, “férreo”. Hermano y compañero de la Discordia.
Pasó mucho tiempo para que los humanos tuviéramos una nueva visión del planeta. A finales del siglo XVI e inicios del XVII el telescopio fue inventado. En agosto de 1609, Galileo mostró el primer telescopio astronómico. Y de inmediato, todo cambió. En 1610 publicó Sidereus Nuncius donde, describe un historiador, sobre Marte refirió que "su tamaño aparente es más brillante y cuatro veces mayor que el año anterior y que presenta aspecto giboso, o sea fase, pero no ve detalles en la superficie. Deduce que es un cuerpo carente de luz propia, o sea iluminado por el Sol, que se acerca y aleja hasta 4 veces de la Tierra. Escribe a su amigo, el Padre Castelli, que Marte es un objeto difícil de observar". En 1666, en Bologna, Domenico Cassini, descubrió la rotación del planeta alrededor de un eje oblicuo.
 |
| Así se veía Marte en 1832. Fuente: Schiaparelli; 1893 |
En 1830, un astrónomo alemán, Maedler, publicó lo que puede ser considerada la primera "Areografia". A finales del siglo XIX e inicios del XX, un astónomo italiano, Giovanni Schiaparelli, pasó a la posteridad por su interés en Marte. El tuvo la oportunidad de vivir el alineamiento de la Tierra entre el Sol y Marte que, en las noches, se ubicaba en su posición más cercana a la Tierra (un mayor diámetro con mejores condiciones de observación telescópica). "Trovandosi allora i tre corpi (Sole, Terra, Marte) in linea retta, e la Terra (come quella che è più vicina al Sole) occupando il posto di mezzo, allo spettatore terrestre, Marte ed il Sole appariranno in plaghe opposte al cielo; e questo intendono dire gli astronomi quando parlano di Marte in opposizione col Sole. Le epoche adunque in cui Marte si presenta a noi più vicino, sono quelle delle opposizioni, le quali ricorrono ad intervalli di circa ventisei mesi, o 780 giorni" (Fuente).
En 1877, Marte se veía así:
En 1877, Marte se veía así:
 |
| Así se veía Marte entre 1877 y 1893. Fuente: Schiaperelli, 1893 |
Con las observaciones que se fueron acumulando, el mapa marciano, hacia 1888, había cambiado así:
 |
| Así se Veía Marte en 1888. Fuente: Schiaparelli |
Lo que posteriormente describió Shiaparelli, no solo aportó al conocimiento astronómico sino que, desde entonces, la hipótesis de vida en Marte cobró vida. Ayudó que, para entonces, la existencia de casquetes polares se diera como un hecho, que "in ogni clima e sotto ogni zona la sua atmosfera è quasi perpetuamente serena e trasparente abbastanza per lasciar riconoscere a qualunque momento i contorni dei mari e dei continenti, e per lo più anche le configurazioni minor" y que "il clima di Marte nel suo generale complesso dovrebbe rassomigliare a quello delle giornate serene nelle alte montagne".
Entre 1893 y 1905 Schiaparelli publicó tres artículos en la Revista "Naturaleza y Arte" donde hizo públicas sus observaciones sobre Marte.: "Il pianeta Marte" (1893), "La vita sul pianeta Marte" (1895) y "Il pianeta Marte" ( 1909). En la "La vita sul pianeta Marte", 1895 escribió: "Oggi è nata presso alcuni la speranza, che da osservazioni diligenti fatte sulla sua superficie con giganteschi telescopi, si possa ottenere quando che sia la soluzione di un gran problema cosmologico; arrivar cioè a sapere, se i corpi celesti possano dirsi sede di esseri intelligenti, o, almeno, di esseri organizzati" ("si de los cuerpos celestes puede decirse que son lugar de seres inteligentes o, al menos, seres orgánicos") y agregó, en realidad, "l’idea di popolare gli astri e le sfere celesti d’intelligenze pure o corporee, di animali e di piante, non è nuova".
 |
| Y los canales estaban geométricamente alineados. Marte visto en 1890. Fuente. Shiaparelli |
Sin embargo, reconoció, "ma pur troppo è da confessare che, quanto a risultati di osservazione, finora abbiamo poche speranze e nessun fatto". La Luna, "un deserto di aride rupi, privo d’ogni elemento necessario alla vita organica". De Venus, casi para siempre, será imposible ver su interior debido a su " atmosfera è perpetuamente ingombra di dense nuvole". De Jupiter, Saturno, Urano y Neptuno ("los planetas grandes"), sería imposible saberlo, dada su distancia. Mercurio presenta dificultades dada la "avviluppato com’egli è di continuo nella luce del Sole". Y agrega: "Non parliamo nè del Sole, nè delle stelle, nè delle comete, nè delle nebule; tutti corpi, dei quali la costituzione fisica non sembra propria alla produzione e alla conservazione della vita, almeno nelle forme con cui noi l’intendiamo".
Así que...solo Marte quedó..."Tutte le nostre speranze si sono quindi poco a poco concentrate su Marte il solo astro che possa giustificarle sino ad un certo punto, siccome or ora si vedrà" y sobre todo porque "dopo che un esame accurato di quel pianeta ha fatto scoprire in esso alcuni cambiamenti, e un sistema di misteriose configurazioni, in cui con un po’ di buona volontà si potrebbe congetturare piuttosto il lavoro di esseri intelligenti, anzi che la semplice opera delle forze naturali inorganiche".
Para entonces, el astrónomo italiano describió a Marte, como "un Insomma il pianeta non è un deserto di arido sasso; esso vive, e la sua vita si manifesta alla superficie con un insieme molto complicato di fenomeni, ed una parte di questi fenomeni si sviluppa su scala abbastanza grande per riuscire osservabile agli abitatori della Terra".
En 1888, Shiaparelli publicó varios mapas especiales de Marte. En Il pianeta Marte (1893) escribió: "Queste linee o strisce sono i famosi canali di Marte, di cui tanto si è parlato...Ogni canale (per ora chiamiamoli così) alle sue estremità sbocca o in un mare, od in un lago, od in un altro canale, o nell’intersezione di più altri canali"
 |
| Marte el 20 de setiembre de 1909. Fuente: Schiaparelli |
En 1906, Lowel anunció haber descubierto agua y oxígeno. En 1909, Schiaparelli, encontró un argumento adicional a su hipótesis de vida en Marte: "Con queste scoperte egli ha trovato un importante argomento in favore dell’ipotesi da lui con molto ingegno e con gran copia di osservazioni sostenuta, che Marte sia pur sede della vita, come la Terra; e che i fenomeni di variazione osservati sul pianeta sian dovuti principalmente alla vegetazione razionalmente governata da esseri intelligenti".
¿Vida en Marte?¿Pudieron aquellos canales ser obra de vida artificial? Un científico, siguiendo a Schiaparelli, afirmó que sí. Percival Lowell, estadounidense, escribió sus cobservaciones en tres obras diferentes: Mars (1895), Mars and Its Canals (1906), y Mars As the Abode of Life (1908).
En su obra de 1895, Lowell escribió: "In the last chapter we saw how badly off for water Mars, to all appearance, is; so badly off that inhabitants of that other world would have to irrigate to live. As to the actual presence there of such folk, the broad physical characteristics of the planet express no opinion beyond the silence of consent, but they have something very vital to say about the conditions under which alone their life could be led. They show that these conditions must be such that in the Martian mind there would be one question perpetually paramount to all the local labor, women's suffrage, and Eastern questions put together--the water question. How to procure water enough to support life would be the great communal problem of the day" .
Así, los canales como producto de vida inteligente adquirieron una forma definitiva, diríase, para siempre instalándose en el imaginario de las personas, gracias, por ejemplo, a "La Guerra de los Mundos", la novela de ciencia ficción de Herbert George Wells, publicada por primera vez en 1898, que describe una invasión marciana a la Tierra e inmortalizada por la versión radial de Orson Welles, en 1938.
Pero no para la ciencia. En 1907, Alfred Russel Wallace, publicó "Is Mars Habitable?. A Critical Examination of Professor Percival Loell's Book 'Mars and its Canal's, with an Alternative Explanation", donde escribió "This small volume was commenced as a review article on Professor Percival Lowell's book, Mars and its Canals with the object of showing that the large amount of new and interesting facts contained in this work did not invalidate the conclusion I had reached in 1902, and stated in my book on Man's Place in the Universe that Mars was not habitable", ofreciendo una explicación alternativa que hizo que la teoría de Lowell perdiera peso en el mundo científico.
Curiosamente, con el Viking 1, el 25 de julio de 1976, la tesis de vida inteligente en Marte resurgió, cuando aquellas imágenes de la Región de Cydonia fueron divulgadas:
Aunque, ciertamente, no por mucho tiempo. Las fotografías tomadas por la sonda Mars Global Surveyor, entre 1997 y el 2006, acabaron con toda esperanza.
¿Qué no haya vida inteligente significa que no haya o no haya existido vida en Marte? No necesariamente. De hecho, hoy más que nunca, dicha hipótesis es más fuerte que nunca.
El Sol
Hesiodo, en la “Teogonía”, el primer esfuerzo de sistematización mítica, lo describe como “brillante”, “infatigable”, el de “la espléndida luz”, aquel que “da luz a los hombres”, el que “alumbra con sus rayos”. El Sol personificado en el “Gran Helios”; la “fuerza del ardiente Helios”. Nieto de Gea (la Tierra) y Urano (el Cielo). Hijo de los Titanes Hiperión (fuego astral) y Tea (la vista). Hermano de Selene (la luna) y Eos (la aurora). Múltiple Padre. Cuenta Hesiodo que las Musas Heliconiadas le cantaban y alababan, en la montaña del Helicón. Para entonces, Helios, cruzaba el cielo con sus caballos, en torno a la corriente de Océano, regresando al este, antes del alba. Un poeta ateniense del siglo VII ac, escribe que lo hacía en un cuenco de oro tirado por caballos. Pocos después, se consideraba nacía todos los días, producto de exhalaciones procedentes del mar.
Hoy sabemos que no es así. Pero la magnanimidad del Sol sigue siendo la misma
NASA has just released new movies of an "inky-dark" solar explosion that continues to puzzle experts more than a month after it happened.
jueves, 15 de septiembre de 2011
Video: Two Suns Set on Alien World - ScienceNOW
This video may be the closest you come to a visit with a real-life Tatooine. Astronomers have discovered the first planet that, like Luke Skywalker's fictional home world in Star Wars, orbits two suns. The stars are a binary pair: They are about 1.5 and 4.5 times smaller than our own sun, and they orbit each other every 41 days, causing brightness dips that have been detected by the Kepler space telescope. Kepler also spied additional dips, produced when a Saturn-sized planet transits across the stars every 229 days. Both stars and planet orbit in the same plane, suggesting they formed together from a single spinning disk of gas and dust, researchers report today in Science. Until now, astronomers weren't sure whether or not planets would be able to form around binary stars. In particular, they thought that when the stars were in an eccentric orbit, as is the case here, they would strongly perturb dust particles that might prevent their coalescence into larger bodies. Kepler was lucky to find the Tatooine planet: Because of our slowly changing view of the system, there will be no planetary transits visible between 2018 and 2042.
This video may be the closest you come to a visit with a real-life Tatooine. Astronomers have discovered the first planet that, like Luke Skywalker's fictional home world in Star Wars, orbits two suns. The stars are a binary pair: They are about 1.5 and 4.5 times smaller than our own sun, and they orbit each other every 41 days, causing brightness dips that have been detected by the Kepler space telescope. Kepler also spied additional dips, produced when a Saturn-sized planet transits across the stars every 229 days. Both stars and planet orbit in the same plane, suggesting they formed together from a single spinning disk of gas and dust, researchers report today in Science. Until now, astronomers weren't sure whether or not planets would be able to form around binary stars. In particular, they thought that when the stars were in an eccentric orbit, as is the case here, they would strongly perturb dust particles that might prevent their coalescence into larger bodies. Kepler was lucky to find the Tatooine planet: Because of our slowly changing view of the system, there will be no planetary transits visible between 2018 and 2042.
Suscribirse a:
Entradas (Atom)