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Enfin de serieuses éruptions font leur apparition sur le Soleil.
Seules deux taches sont répertoriées pour l'instant. 1633 au Nord et 1634 au Sud.
Si ça reste en l'état, à peu de choses près, ça va nous faire un beau triangle en face de la Terre pour le 21 décembre.
NASA’s All Sky Fireball Network
The NASA All-sky Fireball Network is a network of cameras set up by the
NASA Meteoroid Environment Office (MEO) with the goal of observing
meteors brighter than the planet Venus, which are called fireballs. The
collected data will be used by the MEO in constructing models of the
meteoroid environment, which are important to spacecraft designers.
The network currently consists of 8 cameras, 6 of which are placed in
locations in north Alabama, north Georgia, southern Tennessee, and
southern North Carolina. The remaining 2 are located in southern New
Mexico. The network is growing all the time, with plans to place a total
of 15 cameras in schools, science centers, and planetaria in the United
States, predominantly east of the Mississippi River, where there are
few such systems.
“What was that bright light in the sky last night?”
Cameras in the network are specialized black and white video cameras
with lenses that allow for a view of the whole night sky overhead.
cameras have overlapping fields of view, which means that the same
fireball can be detected by more than one camera. This allows us to
calculate the height of the fireball and how fast it is going. We can
even work out the orbit of the meteoroid responsible for creating the
fireball, which gives us clues about whether it came from a comet or an
asteroid. If the fireball is traveling slow enough, and makes it low
enough, it is possible that it can survive to the ground as a meteorite.
This website displays fireball data in the form of images, movies,
diagrams, and text files. The data is organized by date. Click on a
date in the list on the left to see the fireballs detected that night.
If the page appears blank that means no fireballs were detected,
probably because of bad weather. The website is automatically updated
every morning at 8:00 am Central Time. Only the last 3 weeks of data is
For more information, contact Dr. Bill Cooke or check out the MEO website.
Space Weather2012-12-13 14:25:00
Du nom de "Luna Ring", l'idée pour le moins originale s'appuie sur une
"ceinture solaire" de 10 920 kms où la lumière du soleil serait au final
convertie en électricité. Afin d'assurer la production en continue
d'énergie, "un réseau de cellules solaires d'une largeur comprise
entre quelques kilomètres à 40 kms s'étendrait comme une ceinture tout
autour de l'équateur lunaire".
Des câbles se chargeraient de transférer l'énergie produite à partir des
cellules solaires lunaires aux installations de transport. Des antennes
de 20 kilomètres de diamètre transmettraient ainsi l'énergie aux
stations terrestres de réception. D'autres installations de transmission
comme le laser à haute densité énergétique seraient également
utilisées. Dans tous les cas, une balise de guidage (radio beacon)
permettrait d'en assurer une transmission exacte.
Les ressources lunaires seraient exploitées dans la mesure du possible
pour réaliser la construction de la ceinture solaire. Selon Shimizu,
l'eau pourrait être produite sur place en combinant des éléments du sol
lunaire avec de l'hydrogène importé de la Terre. Des matériaux servant à
la cimentation pourraient également provenir de ressources lunaires.
Des briques, des fibres de verre et d'autres matériaux de construction
pourraient être fabriqués par des processus de chaleur solaire.
Enfin, les robots joueraient un rôle essentiel dans la construction
de l'anneau solaire, où ils seraient télé-opérés 24 heures par jour à
partir de la Terre.
Les avantages du concept dans l'espace :
- Élimine les inconvénients liés aux mauvaises conditions météorologiques
- Fourniture d'énergie 24/24h et 7/7j
- L'énergie solaire serait disponible, quelque soit le lieu sur terre
NASA moon probes are slated to slam into the rim of a lunar crater
today (Dec. 17), and the space agency will give viewers a
behind-the-scenes look at the dramatic action.
these surprise radio jets observed in Hercules A Galaxy, to a stunning
meteor shower and view of our Earth on 12/12/12, don't miss these
amazing space pictures.
Read More »
A new video captures the giant asteroid 4179 Toutatis tumbling through space on its flyby of Earth earlier this week.
The moon serves as a graveyard for the remains of at least 71 space vehicles that landed or crashed there over the years.
by Nancy Atkinson on December 18, 2012
Want to stay on top of all the space news? Follow @universetoday on Twitter
The planned path of the GRAIL spacecrafts’ final orbit. Credit: NASA
“So long, Ebb and Flow, and we thank you,” said GRAIL project manager
David Lehman of NASA’s Jet Propulsion Laboratory after the twin GRAIL
spacecraft completed a planned formation-flying double impact into the
southern face of 2.5-kilometer- (1.5-mile-) tall mountain on a crater
rim near the Moon’s north pole. Mission team members estimate the two
spacecraft were traveling at a speed of 1.7 kilometers per second (3,760
mph), and likely broke apart on impact. NASA said that most of what
remains of the washing machine-sized spacecraft are probably buried in
shallow craters, and the size of those craters will hopefully be
determined when NASA’s Lunar Reconnaissance Orbiter is able to image the
impact site in about two weeks.
NASA has honored the GRAIL team’s request to name Ebb and Flow’s
impact sites after astronaut Sally Ride, who passed away earlier this
year. She was America’s first woman in space and a member of the GRAIL
A simulation of the GRAIL impacts:
Impact occurred at 10:28:51 UTC (5:28:51 p.m. EST) and 10:29:21 UTC
(5:29:21 p.m. EST). Right now it is night at the impact site, so
sunlight should return within two weeks, enabling imaging of the site.
LRO also took “before” images of the site during previous daylight
The impact marked a successful end to the GRAIL(Gravity Recovery and
Interior Laboratory)mission, which in just a 90-day prime mission
generated the highest-resolution gravity field map of any celestial body
— including Earth — and determined the inner crust of the Moon is
“Ebb and Flow have removed a veil from the Moon,” said GRAIL
principal investigator Maria Zuber during a televised commentary of the
impacts today, adding that the mission will enable discoveries for years
Data from GRAIL’s extended mission and main science instruments are
still being analyzed, and the findings will provide a better
understanding of how Earth and other rocky planets in the solar system
formed and evolved.
GRAIL was NASA’s first planetary mission to carry cameras fully
dedicated to education and public outreach. Ride, who died in July after
a 17-month battle with pancreatic cancer, led GRAIL’s MoonKAM (Moon
Knowledge Acquired by Middle School Students) Program through her
company, Sally Ride Science. The camera took more than 115,000 total
images of the lunar surface, and imaging targets were proposed by middle
school students from across the country and the resulting images
returned for them to study.
“Sally was all about getting the job done, whether it be in exploring
space, inspiring the next generation, or helping make the GRAIL mission
the resounding success it is today,” said Zuber. “As we complete our
lunar mission, we are proud we can honor Sally Ride’s contributions by
naming this corner of the Moon after her.”
Last Friday, Ebb and Flow, the two spacecraft comprising NASA’s
Gravity Recovery and Interior Laboratory (GRAIL) mission, were commanded
to descend into a lower orbit that would result in an impact Monday on a
mountain near the Moon’s north pole.
Fifty minutes prior to impact, the spacecraft fired their engines
until the propellant was depleted. The maneuver was designed to
determine precisely the amount of fuel remaining in the tanks. This will
help NASA engineers validate computer models to improve predictions of
fuel needs for future missions.
Screenshot of engineering data showing trajectory of the two GRAIL spacecraft about 2 minutes before Ebb’s impact. Via NASA TV.
“Ebb fired its engines for 4 minutes 3 seconds, and Flow fired its
for 5 minutes 7 seconds,” Lehman. “It was one final important set of
data from a mission that was filled with great science and engineering
Launched in September 2011, Ebb and Flow had been orbiting the moon
since Jan. 1, 2012. The probes were intentionally crashed into the lunar
surface because they did not have sufficient altitude or fuel to
continue science operations.