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The icy giant worlds Uranus and Neptune are the least studied planets in the Solar System. Of all the space probes only Voyager 2 visited them, and their great distance from the Sun (and therefore Earth) makes them difficult to study with ground-based telescopes. As a result many aspects of the planets are mysterious, including the strong winds in their atmospheres.
by Claude Lafleur Monday, March 8, 2010 Everybody knows that the Apollo program costs $20 billion in 1970s dollars—the equivalent of $100 billion in today’s money. But that’s about all most of us know about piloted program costs. For instance, who knows how much the Space Shuttle and the International Space Station programs cost? How much does each Shuttle flight cost?
In late March last year, the people operating the Fermi Gamma-ray Space Telescope got a bit of a scare. Their hardware was one week away from a close encounter with a defunct Russian spy satellite. A week might seem like short notice for one-of-a-kind hardware like Fermi, but in some ways the team was lucky to have any warning at all. Prior to 2007, NASA didn't even have a policy in place to identify threats to unmanned hardware.
By Craig Pearson on May 10th, 2013 at 4:00 pm. My application to be an astronaut was turned down because it was written in crayon, and now that I read it back in the cold light of day I notice it appeared pretty threatening. Sorry, NASA! My aluminum hat must have slipped and enabled an alien to take control of my writing arm.
A new dark matter detector has gone online today, using a rather clever method of searching for signs of rare interactions between dark and regular matter. The tool uses a liquid that's kept poised on the edge of boiling, such that even the tiniest bit of additional energy—say, caused by the impact of a dark matter particle—will create a bubble of vapor in the detector. The new detector is called COUPP , for Chicagoland Observatory for Underground Particle Physics. Although it was organized by Fermilab outside of Chicago, the detector resides in Canada's SNOLAB , deep in a mine near Sudbury, Ontario. This location shields it from a lot of the background noise of particles that come from the atmosphere and radioactive substances.
In the Newtonian view of the world, binary star systems should remain in a stable orbit in perpetuity, no matter how massive the objects or how close the orbit. But with general relativity, that changes; energy gets carried away from the system in the form of gravity waves, which gradually causes the orbit to decay, ultimately leading to a merger. By observing binary systems of massive objects, we've determined that general relativity gets it right .
Gamma-ray bursts are some of the most violent phenomena in the Universe: the explosions of extremely massive stars. Early in the morning of April 27, 2013, an exceptionally bright gamma-ray burst (GRB) triggered the automatic detection system aboard the orbiting Fermi Gamma Ray Telescope. The system located the explosion within the constellation Leo. Observations by Fermi, the Swift X-ray observatory, and ground-based visible-light observatories determined the GRB was about 3.6 billion light-years away—relatively close for such an incident. The event, labeled GRB 130427A, was the most energetic gamma-ray burst yet seen . It also had the longest duration.
The general theory of relativity is a remarkably successful model for gravity. However, many of the best tests for it don't push its limits: they measure phenomena where gravity is relatively weak. Some alternative theories predict different behavior in areas subject to very strong gravity, like near the surface of a pulsar—the compact, rapidly rotating remnant of a massive star (also called a neutron star). For that reason, astronomers are very interested in finding a pulsar paired with another high-mass object. One such system has now provided an especially sensitive test of strong gravity.
Asteroids are old. Really, really old. They formed at the same time as the planets, so when their pieces fall to Earth, they deliver 4.56 billion- year-old mementos that allow us to touch the birth of the Solar System. But some small bits in those meteorites are even older , if you’re limber enough for a little more mind-bendingly deep time. Some mineral grains that ended up in the Solar System formed in other stars. Most that have been found so far formed in certain types of red giant stars.
Vous connaissez très certainement Stargate ou Portal. Tous deux font la part belle aux portails, comme « moyen de transport ». Si l’on n’est pas prêt d’utiliser un tel système, la NASA étudie en tout cas des portails bien particuliers de notre système solaire.
When we think of NASA, we mainly think of exploration beyond Earth, but the agency is just as dedicated to exploring and studying scientific processes here on our planet. NASA has been especially vigilant when it comes to monitoring the environment and collecting data on the effects of climate change. From high tech tools aboard satellites to specialized drones, the following are ten cool projects the space agency has taken on over the past few years that are giving us a better understanding of how our world works and what we can do to protect it.
I have to say, although I actually like the style of music that plays over top here, it just doesn't fit. A few days ago when a friend of mine linked to this video on Facebook, I took a minute and swapped in the first song that came to mind that *did* fit (a bit of a snide choice, even, since the same artist often does glitchier, more electronic music) and it confirmed for me that the music selection here was sub-optimal. 11/20/11 12:13am <p style="text-align:right;color:#A8A8A8"></p>
Pour mettre un satellite en orbite ou envoyer une capsule ravitailler la Station spatiale internationale , il n’y a plus besoin que des gouvernements forts demandent un effort national. Il suffit simplement de décrocher son téléphone et de demander à des sociétés privées si elles ont un vol libre dans les 10 prochaines années. Aujourd’hui, Orbital Sciences Corp vient de réussir son premier vol d’essai en envoyant sa fusée Antares embarquant 3,8 tonnes de charge en orbite autour de la Terre. Orbital Sciences est une des 2 sociétés (l’autre s’appelle SpaceX ) à avoir décroché un contrat avec la NASA pour ravitailler la Station spatiale internationale tant que les États-Unis n’ont pas de navette ou de capsule exploitable.
Liquid water is one of the essential ingredients of life on Earth and it has properties conducive to life in general, so researchers have defined the concept of a habitable zone with water as its focus. For astronomers, the habitable zone is the area far enough from a host star that a planet would be cool enough to support liquid water, but not so far that the water would be frozen. Although there are many caveats to this definition—everything from the presence of greenhouse gasses to clouds will shift a planet's average surface temperature—the concept helps drive the search for a planet capable of supporting life. The caveats, however, have led to a number of arguments over whether a given exoplanet is likely able to host liquid water, with some candidates shifting in and out of the habitable zone more than once. Still, it's pretty clear that given the large number of reported candidate exoplanets , the odds suggest we've already spotted one.
Par Korben Le budget 2014 de la NASA est voté et la mission de capture et de remorquage d'un astéroïde à des fins d'études fait partie de ce budget. Excellente nouvelle ! En apprenant à capturer des astéroïdes, nous pourrons en apprendre plus sur ces corps rocheux et exploiter leurs ressources minières.