NASA - NASA Ends Attempts to Fully Recover Kepler Spacecraft, Potential New Missions Considered

NASA Ends Attempts to Fully Recover Kepler Spacecraft, Potential New Missions Considered

Following months of analysis and testing, the Kepler Space Telescope team is ending its attempts to restore the spacecraft to full working order, and now is considering what new science research it can carry out in its current condition.

Two of Kepler's four gyroscope-like reaction wheels, which are used to precisely point the spacecraft, have failed. The first was lost in July 2012, and the second in May. Engineers' efforts to restore at least one of the wheels have been unsuccessful.

Kepler completed its prime mission in November 2012 and began its four-year extended mission at that time. However, the spacecraft needs three functioning wheels to continue its search for Earth-sized exoplanets, which are planets outside our solar system, orbiting stars like our sun in what's known as the habitable zone -- the range of distances from a star where the surface temperature of a planet might be suitable for liquid water. As scientists analyze previously collected data, the Kepler team also is looking into whether the space telescope can conduct a different type of science program, including an exoplanet search, using the remaining two good reaction wheels and thrusters.

"Kepler has made extraordinary discoveries in finding exoplanets including several super-Earths in the habitable zone," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington. "Knowing that Kepler has successfully collected all the data from its prime mission, I am confident that more amazing discoveries are on the horizon."

On Aug. 8, engineers conducted a system-level performance test to evaluate Kepler's current capabilities. They determined wheel 2, which failed last year, can no longer provide the precision pointing necessary for science data collection. The spacecraft was returned to its point rest state, which is a stable configuration where Kepler uses thrusters to control its pointing with minimal fuel use.

"At the beginning of our mission, no one knew if Earth-size planets were abundant in the galaxy. If they were rare, we might be alone," said William Borucki, Kepler science principal investigator at NASA's Ames Research Center in Moffett Field, Calif. "Now at the completion of Kepler observations, the data holds the answer to the question that inspired the mission: Are Earths in the habitable zone of stars like our sun common or rare?

An engineering study will be conducted on the modifications required to manage science operations with the spacecraft using a combination of its remaining two good reaction wheels and thrusters for spacecraft attitude control.

Informed by contributions from the broader science community in response to the call for scientific white papers announced Aug. 2, the Kepler project team will perform a study to identify possible science opportunities for a two-wheel Kepler mission.

Depending on the outcome of these studies, which are expected to be completed later this year, NASA will assess the scientific priority of a two-wheel Kepler mission. Such an assessment may include prioritization relative to other NASA astrophysics missions competing for operational funding at the NASA Senior Review board early next year.

From the data collected in the first half of its mission, Kepler has confirmed 135 exoplanets and identified over 3,500 candidates. The team continues to analyze all four years of collected data, expecting hundreds, if not thousands, of new discoveries including the long-awaited Earth-size planets in the habitable zone of sun-like stars. Though the spacecraft will no longer operate with its unparalleled precision pointing, scientists expect Kepler’s most interesting discoveries are still to come. 

Meanwhile, preparations are underway for hosting the second Kepler Science Conference Nov. 4-8, at NASA's Ames Research Center. This will be an opportunity to share not only the investigations of the Kepler project team, but also those of the wider science community using publicly accessible data from Kepler. Registration is now open. For more information about Kepler's upcoming science conference, visit:

http://go.nasa.gov/13kz012

For more information about NASA's call for two-wheel science proposals, visit:

http://go.nasa.gov/1a1UzaC

For more information about NASA's Kepler spacecraft, visit:

http://www.nasa.gov/kepler

NASA

Guillermo Gonzalo Sánchez Achutegui

ayabaca@gmail.com

ayabaca@hotmail.com

ayabaca@yahoo.com

NASA - Kepler Data Reveal First Transiting Planets in a Star Cluster

Kepler Data Reveal First Transiting Planets in a Star Cluster

June 27, 2013

In the star cluster NGC 6811, astronomers have found two planets smaller than Neptune orbiting sun-like stars.

Image Credit: 

Michael Bachofner

Astronomers have found two planets smaller than three times the size of Earth orbiting sun-like stars in a crowded stellar cluster approximately 3,000 light-years from Earth in the constellation Cygnus.
This finding demonstrates that small planets can form and persist in a densely packed cluster environment, and implies that the frequency and properties of planets in open clusters are consistent with those of planets around field stars not associated with clusters, like our sun, in the galaxy. The paper was published June 26, 2013, in the journal Nature.
"These planets are cosmic extremophiles," said lead author Soren Meibom of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. "Finding them shows that small planets can form and survive for at least a billion years, even in a chaotic and hostile environment."
Of the more than 850 known planets beyond our solar system, only four - all similar to or greater than Jupiter in mass – were found in clusters. Kepler-66b and Kepler-67b are the smallest planets to be found in a star cluster, and the first cluster planets seen to transit their host stars, which enables the measurement of their sizes.
For more information about the discovery, see the CfA press release or the paper published in the journal Nature.

NASA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com

Astronomía: Descubren un planeta mayor que la Tierra

Hola mis amigos: AL  VUELO DE UN QUINDE EL BLOG., Un equipo de astrónomos ha descubierto una versión más grande de la Tierra próxima a otro planeta aún mayor y que orbita junto a él en torno a la misma estrella, a unos 1.200 años luz, según un artículo que publica hoy la revista Science Express.

La revista Science Express publica hoy que un equipo de astrónomos ha descubierto una versión más grande de la Tierra próxima a otro planeta aún mayor y que orbita junto a él en torno a la misma estrella, a unos 1.200 años luz. En la foto de archivo, sin fecha, tomada por el telescopio espacial Hubble de una pequeña región de la Nebulosa del Cisne, también conocida como M17.  EFE/Nasa.

 Washington, 26 jun (EFEverde).- Un equipo de astrónomos ha descubierto una versión más grande de la Tierra próxima a otro planeta aún mayor y que orbita junto a él en torno a la misma estrella, a unos 1.200 años luz, según un artículo que publica hoy la revista Science Express.

Los planetas ocupan casi el mismo plano orbital y cuando están más próximos la distancia entre ellos es de 1,95 millones de kilómetros, esto es cinco veces la distancia de la Tierra a la Luna y unas veinte veces menor que la distancia entre cualquiera de los planetas en el sistema solar.
Pero, según los astrónomos de las universidades de Washington (UW) y Harvard, los tiempos de sus órbitas determinan que jamás colisionarán.
"Estos son los dos planetas más cercanos uno al otro que hemos encontrado", dijo Eric Agol, profesor de astronomía en la UW y uno de los autores principales del artículo. "El planeta más grande empuja al más chico y por eso es más difícil encontrar al menor".
4,5 veces mayor que la Tierra
Los planetas, que orbitan la estrella Kepler-36a en la constelación del Cisne, se han designado como Kepler-36b y Kepler-36c.
El planeta b es un cuerpo rocoso como la Tierra aunque con una masa 4,5 veces mayor y un radio 1,5 veces más largo. Kepler-36c, que podría ser gaseoso como Júpiter o lleno de agua, es 8,1 veces más grande que la Tierra y tiene un radio 3,7 veces más extenso.
El planeta más grande fue descubierto originalmente en los datos provistos por el observatorio orbital Kepler, de la agencia espacial estadounidense NASA, que usa un fotómetro para medir la luz de los objetos celestes distantes.
Este instrumento permite detectar un planeta cuando transita entre la estrella en torno a la cual orbita y la Tierra, y reduce brevemente la luz que proviene de la estrella.
Tras ese primer descubrimiento los astrónomos se dedicaron a ver si el sistema contenía un segundo planeta, y Agol sugirió el uso de un algoritmo denominado detección de pulso cuasi periódica para el examen de los datos del Kepler.
Revisan los datos de Kepler
El otro coautor principal del artículo, Joshua Carter, quien trabaja con el observatorio Hubble en el Centro Harvard Smithsonian para Astrofísica, empleó el algoritmo para inspeccionar metódicamente los sistemas planetarios registrados en los datos del Kepler, y vio en el sistema Kepler-36a una señal clara.
"Encontramos ésta en un primer vistazo rápido", señaló Carter. "Ahora revisamos con más cuidado los datos del Kepler para ver si localizamos más planetas".
Los datos mostraron una leve atenuación cada 16 días de la luz que proviene de la estrella Kepler-36a y ése es el período de órbita del planeta Kepler-36c.
Por su parte Kepler-36b orbita la estrella siete veces por cada seis órbitas del 36c, pero inicialmente no se le había percibido debido a su tamaño pequeño y el empujón gravitacional de su compañero de órbita.
Cuando se aplicó el algoritmo, explicaron los científicos, la señal fue inconfundible.
Hierro, hidrógeno y agua
"Si uno observa el patrón de tiempo de tránsito del planeta mayor y el patrón de tiempo de tránsito del planeta menor son como imágenes reflejadas en un espejo", dijo Agol.
Los científicos creen que el 30 por ciento del planeta menor consiste en hierro, y que tiene una atmósfera en la cual menos del 1 por ciento es hidrógeno y helio y con no más de un 15 por ciento de agua.
En cambio, el planeta más grande probablemente tiene un núcleo rocoso rodeado por una cantidad sustancial de hidrógeno y helio atmosféricos. EFEverde

¡compártelo!

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 Guillermo Gonzalo Sánchez Achutegui
 ayabaca@gmail.com
 ayabaca@hotmail.com
 ayabaca@yahoo.com 

Astronomy: NASA's Kepler Releases New Catalog- 2,321 Planet Candidates

Hi My Friends: AL VUELO DE UN QUINDE EL BLOG., The histogram summarizes the findings in the Feb. 27, 2012 Kepler Planet Candidate catalog release. The catalog contains 2,321 planet candidates identified during the first 16 months of observation conducted May 2009 to September 2010. Of the 46 planet candidates found in the habitable zone, the region in the planetary system where liquid water could exist, ten of these candidates are near-Earth-size. Kepler Planet Candidates by Size, Feb. 27, 2012
The histogram summarizes the findings in the Feb. 27, 2012 Kepler Planet Candidate catalog release. The catalog contains 2,321 planet candidates identified during the first 16 months of observation conducted May 2009 to September 2010. Of the 46 planet candidates found in the habitable zone, the region in the planetary system where liquid water could exist, ten of these candidates are near-Earth-size.

Credit: NASA Ames/Wendy Stenzel.

Since science operations began in May 2009, the Kepler team has released two catalogs of transiting planet candidates. The first catalog (Borucki et al, 2010), released in June 2010, contains 312 candidates identified in the first 43 days of Kepler data. The second catalog (Borucki et al, 2011), released in February 2011, is a cumulative catalog containing 1,235 candidates identified in the first 13 months of data.

Today the team presents the third catalog containing 1,091 new planet candidates identified in the first 16 months of observation conducted May 2009 to September 2010. These are the same candidates that the team discussed at the Kepler Science Conference held at NASA Ames Research Center in December 2011.

Here are the highlights of the new catalog:
A.- Planet candidates smaller than twice the size of Earth increased by 197 percent, compared to 52 percent for candidates larger than twice the size of Earth.
B.- Planet candidates with orbital periods longer than 50 days increased by 123 percent, compared to 85 percent for candidates with orbital periods shorter than 50 days. Since the last catalog was released in February 2011, the number of planet candidates identified by Kepler has increased by 88 percent and now totals 2,321 transiting 1,790 stars.

The cumulative catalog now contains well over 200 Earth-size planet candidates and more than 900 that are smaller than twice Earth-size. Of the 46 planet candidates found in the habitable zone, the region in the planetary system where liquid water could exist, ten of these candidates are near-Earth-size.

The number of planetary systems found with more than one planet candidate also has increased. Last year, 17 percent, or 170 stars, had more than one transiting planet candidate. Today, 20 percent, or 365, stars have more than one.

"With each new catalog release a clear progression toward smaller planets at longer orbital periods is emerging, " said Natalie Batalha, Kepler deputy science team lead at San Jose State University in California. "This suggests that Earth-size planets in the habitable zone are forthcoming if, indeed, such planets are abundant.

"Nearly 5,000 periodic transit-like signals were analyzed with known spacecraft instrumentation and astrophysical phenomena that could masquerade as transits, which can produce false positives. The most common false positive signatures are associated with eclipsing binary stars- a pair of orbiting stars that eclipse each other from the vantage point of the spacecraft.

The Kepler space telescope identifies planet candidates by repeatedly measuring the change in brightness of more than 150,000 stars in search of planets that pass in front, or "transit," their host star. Kepler must record at least three transits to verify a signal as a planet.

The findings are published in the "Planetary Candidates Observed by Kepler III: Analysis of the First 16 Months of Data".

The catalog is available at the Kepler data archive at the Space Telescope Science Institute and can be downloaded from the NASA Exoplanet Archive.

NASA's Ames Research Center in Moffett Field, Calif., manages Kepler's ground system development, mission operations and science data analysis. NASA’s Jet Propulsion Laboratory, Pasadena, Calif., managed the Kepler mission's development.

Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.

For information about the Kepler Mission,

visit: http://www.nasa.gov/kepler
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com

ayabaca@hotmail.com

ayabaca@yahoo.com