Ça bouge dans l'espace
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Les informations que vous trouverez sur cette page viennent des sources suivantes :
et de plusieurs sites de la NASA et l’ESA
La page est organisée en deux sections. Dans la première section vous pouvez lire une synthèse des événements astronomiques et spatiaux de la semaine écoulée et dans la deuxième section les événements à ne pas manquer dans la semaine qui vient.
Comme ce le troisieme lundi du mois, vous trouverez, en bas du page, un dossier PowerPoint. Cette mois, comme il avait le premier soirée mondiale d'observation de Saturne, le présentation est sur "Cassini" et je vous invite de l'utiliser avec vos élèves ou dans votre club d'astronomie.
Si vous avez des informations intéressantes que vous voulez partager, n’hésitez pas à me les envoyer à l’adresse suivante : boblarcher@yahoo.com
La semaine dernière dans l’espace ! In English this week!!
The latest photograph taken by the Spitzer Space Telescope shows a bizarre false colour view of the Helix Nebula. Located around 700 light years from Earth, in the constellation of Aquarius, this beautiful nebula used to be a star similar to our own Sun. As it died, it sloughed off its outer layers, creating the view we see today. Enjoy the view while you can. Astronomers think that it’ll disappear within 10,000 years or so. The colourful clouds will fade, and all we’ll see is tiny white dwarf ember slowly cooling to the ambient temperature of the Universe. A fate that our Sun will eventually share. For more information, click here: http://www.spitzer.caltech.edu/Media/releases/ssc2007-03/release.shtml.
Astronomers have taken 4,000 of the brightest quasars and figured out just how much dark matter surrounds them. As we’re starting to learn, wherever there’s matter, there’s 10x as much dark matter. These quasars back that theory up. The survey was done using the Sloan Digital Sky Survey (SDSS-II); a detailed data set that will eventually contain more than 25% of the sky. Astronomers are continuously poring through this data, and finding nuggets of information for their theories. With this latest research, a team of astronomers led by Yue Shen from Princeton University determined the position of 4,000 bright quasars. Quasars are some of the brightest objects in the Universe, and they’re thought to be the radiation emitted by actively feeding supermassive black holes at the hearts of distant galaxies. They’re so bright, they can be seen from billions of light-years away, at a time when the Universe was only a few billion years old. For more information, click here: http://www.sdss.org/news/releases/20070209.quasar.html.
A new image from NASA's Hubble Space Telescope shows the colorful "last hurrah" of a star like our sun. The picture was taken with Hubble's Wide Field and Planetary Camera 2. The planetary nebula in the image is called NGC 2440. The white dwarf at the center of NGC 2440 is one of the hottest known, with a surface temperature of nearly 200,000 degrees Celsius. The nebula's chaotic structure suggests that the star shed its mass episodically. During each outburst, the star expelled material in a different direction. This can be seen in the two bow tie-shaped lobes. The nebula also is rich in clouds of dust, some of which form long, dark streaks pointing away from the star. NGC 2440 lies about 4,000 light-years from Earth in the direction of the constellation Puppis. For more information click here:
http://www.spacedaily.com/reports/The_Colorful_Demise_of_a_Sun_Like_Star_999.html.
A ne pas manquer la semaine prochaine
Lundi 19 février: Beau rapprochement du fin croissant lunaire avec Vénus, à voir en début de soirée.
Jeudi 22 février: La sonde Cassini survole Titan à une distance prévisionnelle de 950 km. Site de la mission : saturn.jpl.nasa.gov/home/index.cfm
Vendredi 23 février: La lune occulte l'amas des Pléiades.
Samedi 24 février : Élongation maximale de Titan à l’ouest de Saturne - essayez de réperer la sonde Cassini!!
