dimecres, de maig 14, 2008

Notícies de la NASA

Sembla que la NASA està en un període de gran activitat. O, si més no, el seu departament de promoció deu fer hores extres. Dues noticies estan a punt d’ocupar el seu racó a les notícies. Una de prevista i una incògnita.

La prevista és que ja s’està preparant l’arribada a Mart d’una nova missió. La Mars Phoenix Lander arribarà el proper dia 25. Si tot va bé, aviat tindrem un altre robot a la superfície de Mart. Aquest no anirà movent-se com els que ja hi ha, l’Spirit i l’Opportunity, sinó que restarà fix en un indret proper al Pol nord marcià. Un giny molt més semblant a les velles i entranyables missions Víking.

La idea és situar-lo prop d’on hi ha gel per anar analitzant com canvia la composició de la superfície a mida que passa el temps. Es podria esperar que si allà hi ha vida microbiana, durant el desglaç hauria de mostrar-se més activa i es podrien seguir canvis deguts a l’activitat bacteriana.

En tot cas, ha de servir per comprendre millor les condicions climàtiques d’aquella part del planeta, molt més influenciades per la presència de l’aigua en forma de gel.

I la segona notícia de la NASA (gràcies Jacme per l’avís)... doncs la veritat és que encara no se de que es tracta. Han anunciat que avui, a les cinc de la tarda hora d’aquí, donaran una roda de premsa en la que “s’anunciarà el descobriment d’un objecte a la nostra galàxia que els astrònoms han estat buscant durant més de cinquanta anys”.... ?????

De quin objecte parlen? La veritat és que a altres blogs fins i tot han muntat una porra per veure qui endevina de que es tracta. Tampoc hi ha tantes possibilitats. Potser un nou planeta al sistema solar? Potser Nemesi, la hipotètica estrella que hi ha qui creu que acompanya al nostre Sol? Un senyal extraterrestre? (mmm això seria massa). Un planeta realment tipus Terra, amb aigua líquida a la superfície, orbitant un altre Sol?

No crec que sigui el Monstre Volador d’Espagueti, però mai se sap.

La resposta d’aquí a unes hores. Amb una mica de sort serà prou important perquè en parlin a les notícies. Ja és mala sort, perquè avui marxo de viatge i estaré uns dies fora. Quan torni, potser ho comentarem.

9 comentaris :

Carquinyol ha dit...

A mi em sembla una mica trist que la NASA hagi d'utilitzar aquestes tècniques de marketing, la veritat...

Bé, a veure quin objecte serà !! Home, Némesis quedaria molt friki, sincerament... jo em decanto més per un monolit negre... o un stargate !!

;)

Bon viatge !!

Alasanid ha dit...

Si ha estat el Chandra crec que es tractarà d'un forat de cuc i no pas de cap planeta.

Pel que fa a anys ja quadra, els va introduir en Wheeler fa 51 anys.

Que vagin bé aquests dies.

Anna ha dit...

tens un desfasament horari de 2 hores amb la matgala. Espero que tinguis raó tu, que ho sabrem més d'hora!

I mm... les opcions d'en carquinyol m'agraden! tot i que voto pel monolit, que els stargates ja sabem que els hem de descobrir a la Terra!

Jacme ha dit...

pos sí que molaria que fos Némesis (i un mnolit també: així farem a Arthur C. Clarke el nostre profeta!

:D

Anna ha dit...

ho he sentit en directe, ueeeee! ha estat molt emocionant. Acabo d'explicar el que he entès al blog, espero no haver dit gaires barbaritats!

sants ha dit...

Discovery of Most Recent Supernova in Our Galaxy WASHINGTON -- The most recent supernova in our galaxy has been discovered by tracking the rapid expansion of its remains. This result, using NASA's Chandra X-ray Observatory and the National Radio Astronomy Observatory's Very Large Array, will help improve our understanding of how often supernovae explode in the Milky Way galaxy.

The supernova explosion occurred about 140 years ago, making it the most recent in the Milky Way. Previously, the last known supernova in our galaxy occurred around 1680, an estimate based on the expansion of its remnant, Cassiopeia A.

Finding such a recent, obscured supernova is a first step in making a better estimate of how often the stellar explosions occur. This is important because supernovae heat and redistribute large amounts of gas, and pump heavy elements out into their surroundings. They can trigger the formation of new stars as part of a cycle of stellar death and rebirth. The explosion also can leave behind, in addition to the expanding remnant, a central neutron star or black hole.

The recent supernova explosion was not seen with optical telescopes because it occurred close to the center of the galaxy and is embedded in a dense field of gas and dust. This made the object about a trillion times fainter, in optical light, than an unobscured supernova. However, the remnant it caused can be seen by X-ray and radio telescopes.

"We can see some supernova explosions with optical telescopes across half of the universe, but when they're in this murk we can miss them in our own cosmic backyard," said Stephen Reynolds of North Carolina State University in Raleigh, who led the Chandra study. "Fortunately, the expanding gas cloud from the explosion shines brightly in radio waves and X-rays for thousands of years. X-ray and radio telescopes can see through all that obscuration and show us what we've been missing."

Astronomers regularly observe supernovae in other galaxies like ours. Based on those observations, researchers estimate about three explode every century in the Milky Way.

"If the supernova rate estimates are correct, there should be the remnants of about 10 supernova explosions that are younger than Cassiopeia A," said David Green of the University of Cambridge in the United Kingdom, who led the Very Large Array study. "It's great to finally track one of them down."

The tracking of this object began in 1985, when astronomers, led by Green, used the Very Large Array to identify the remnant of a supernova explosion near the center of our galaxy. Based on its small size, it was thought to have resulted from a supernova that exploded about 400 to 1000 years ago.

Twenty-two years later, Chandra observations revealed the remnant had expanded by a surprisingly large amount, about 16 percent, since 1985. This indicates the supernova remnant is much younger than previously thought.

That young age was confirmed in recent weeks when the Very Large Array made new radio observations. This comparison of data pinpoints the age of the remnant at 140 years - possibly less if it has been slowing down - making it the youngest on record in the Milky Way.

Besides being the record holder for youngest supernova, the object is of considerable interest for other reasons. The high expansion velocities and extreme particle energies that have been generated are unprecedented and should stimulate deeper studies of the object with Chandra and the Very Large Array.

"No other object in the galaxy has properties like this," Reynolds said. "This find is extremely important for learning more about how some stars explode and what happens in the aftermath."

These results are scheduled to appear in The Astrophysical Journal Letters. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

Additional information and images about this discovery is available on the Web at:


http://www.nasa.gov/chandra


and


http://chandra.harvard.edu

Assenyat ha dit...

Escolta, et volia sindicar però no trobo cap enllaç per poder-ho fer. No en tens?

JOAN CALSAPEU ha dit...

L'enhorabona per "La catosfera literària".

peperines ha dit...

I ara que?sabem masses coses