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aries1988 : astro   35

BepiColombo, une mission dans le barbecue de Mercure
Selon Alvaro Gimenez, directeur scientifique de l’Agence spatiale européenne, BepiColombo « est probablement la mission scientifique la plus compliquée que l’ESA ait menée ».

Au bout du compte, BepiColombo, tout de blanc et d’argent vêtu, est un monstre de complexité. Ce qui explique les nombreux retards qu’il a subis, les 70 % d’innovations qui le composent et aussi un budget de 1,3 milliard d’euros.
astro  europe  planet  mercury 
july 2017 by aries1988
Cluster analysis
First, the clusters’ very age means that life will have had the best chance of coming into existence and then climbing the ladder of complexity to the point where it can travel from star to star. Second, that age also means clusters have stopped being disrupted by life-destroying stellar explosions like supernovae and gamma-ray bursts. Third, the proximity of a cluster’s stars to one another means interstellar travel is not nearly as onerous as it would be for humanity. A spacefaring cluster-inhabitant would have to travel, on average, only about 1,000 times the distance from Earth to the sun to get to its nearest stellar neighbour. For humans, that distance is 275,000 times the Earth-sun distance. Not only does this make travel easier, it also makes communication practical. Messages between a home planet and its outposts could be sent and received with the same sort of delay as those between European countries and their colonies before the invention of the electric telegraph.
astro  idea  et  life  interstella 
january 2016 by aries1988
Dans le désert d’Atacama, l’Observatoire astronomique de Paranal - RFI
Au Chili, à 1200 km au Nord de Santiago, se trouve le VLT, le plus grand Observatoire astronomique européen, le plus grand Observatoire du monde appartenant à une seule organisation, l’ESO. En plein désert d’Atacama,...
astro  scientist  story  latino 
january 2016 by aries1988
Retrograde Beliefs
In defense of magical thinking.
astro 
july 2015 by aries1988
科学圈怎么吐槽《星际穿越》? | 科学人 | 果壳网 科技有意思
“科学方面我最大的意见是当船员抵达其他星系的时候。明明没有足够的燃料拜访所有行星,却要肉身亲自前往。这引发了船员之间的有趣讨论,因为他们要决定拜访哪颗行星、按照什么顺序。可是现实中,未来的宇航员会先架起望远镜,从远处研究行星大气。使用光谱学,他们能快速而高效低决定哪些星球的环境更适合人类居住。事实上,如果国会肯掏钱,NASA在接下来十年里就能在地球上建起这样一台望远镜——‘类地行星发现者’(TPF)。如果库帕的船员在太空船上架设一台类似望远镜,他们就不必浪费时间在头两个星球上了。当然,省去了登陆也就意味着失去了剧情最富戏剧性的几个瞬间……

“电影制作者花了很大的工夫渲染出科学上准确的黑洞,包括光的弯曲。但是他们好像忽略了多普勒效应和相对论性射束效应。吸积盘快速环绕着黑洞旋转,其中总会有些面向观察者飞来、另一些远离观察者而去,飞来的那些物质看起来应该更蓝也更亮才对。而且虽然电影展现了明亮的吸积盘,可是这些被吸过来的物质却没有显而易见的来源(比如附近的恒星)。”

吸积盘发出的光在我们看来其实是不对称的:因为灼热气体环绕黑洞的速度太快,所以假如图中气体俯视是逆时针旋转,那么左边的气体会向我们飞来,而右边的气体则会离我们而去。这张图只显示了相对论性射束效应(亮暗变化),没有显示多普勒效应(红蓝变化)。图片来源:Chris Reynolds
movie  critic  science  astro 
november 2014 by aries1988
What Our Telescopes Couldn't See - NYTimes.com
I left the world of professional astronomy some time ago. In the years since, I have often thought of how astronomy is seen as a benign, unbiased science. Its sole function is to increase our understanding of how the universe works: astronomers receive and record, but they do not experiment or perturb. They are not tainted by any application to, say, energy development or military technologies. Astronomy is, essentially, a passive science.

I remember realizing when I was a student that I could make a measurement of an object in the sky, and how extraordinary that felt to me, as if it were a way of reaching out and connecting with something so far away. But maybe I found distant galaxies easier to understand than the people around me, and I wonder if my work became a substitute for any true connection. I still look to the edge of the universe, but I try to remember always to keep one eye focused here on earth.
essay  astro  human  science  society  politics  telescope  astronomy  life  americas 
september 2013 by aries1988
Why We Can't Solve Big Problems | MIT Technology Review
July 21, 1969, Buzz Aldrin climbed gingerly out of Eagle, Apollo 11’s lunar module, and joined Neil Armstrong on the Sea of Tranquility. Looking up, he said, “Beautiful, beautiful, magnificent desolation.” They were alone; but their presence on the moon’s silent, gray surface was the culmination of a convulsive collective effort. On July 21, 1969, Buzz Aldrin climbed gingerly out of Eagle, Apollo 11’s lunar module, and joined Neil Armstrong on the Sea of Tranquility. Looking up, he said, “Beautiful, beautiful, magnificent desolation.” They were alone; but their presence on the moon’s silent, gray surface was the culmination of a convulsive collective effort. Kennedy’s words, spoken at Rice University in 1962, provide a better clue:  “But why, some say, the moon? Why choose this as our goal? . . . Why climb the highest mountain? Why, 35 years ago, fly the Atlantic? . . . We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard; because that goal will serve to organize and measure the best of our energies and skills . . .”
http://www.instapaper.com/read/338960349
question  future  nation  astro  human  usa  moon  today 
november 2012 by aries1988
P042412PS-1469 | Flickr - Photo Sharing!
President Barack Obama stops to view the moon and Venus before boarding Marine One in Boulder, Colo., April 24, 2012. (Official White House Photo by Pete Souza)
obama  photo  astro  feelgood 
november 2012 by aries1988
Watch Live: Harvest Moon Meets Up With Uranus in Opposition | Wired Science | Wired.com
Uranus, discovered in 1781 by astronomer William Herschel, is the seventh planet from the sun. The planet is an ice giant, about four times the size of Earth, with an atmosphere composed of hydrogen, helium, and methane, the last of which gives Uranus its familiar blue-green color. Uranus is a strange planet in many ways, not least of which because it orbits on its side — its “North Pole” is about where Earth’s equator is — and it is host of a spectacular array of thin rings and 27 moons. Uranus has only been visited by a spacecraft from Earth once, Voyager 2, which flew by in 1986 and took spectacular images.
googlereader  astro 
october 2012 by aries1988
星系动物园
有15万名天文爱好者参与了星系分类工作。结果,业余人士发现了一些专业天文学家未曾注意到的东西。
googlereader  astro  photo 
september 2012 by aries1988
How to locate where Apollo 11 landed
In tribute to Neil Armstrong who sadly passed away on 25th August 2012, I've put together a quick
guide to locating the landing site of Apollo 11 on the Moon's surface.
astro  howto  moon  history 
august 2012 by aries1988
Obituary: Neil Armstrong | The Economist
"I am, and ever will be, a white-socks, pocket-protector, nerdy engineer, born under the second law of thermodynamics, steeped in steam tables, in love with free-body diagrams, transformed by Laplace and propelled by compressible flow."
googlereader  usa  nasa  engineer  astro  story 
august 2012 by aries1988
Loom Junior • Your morning dose of cosmic perspective: a...
A more realistic simulation of the cosmos (with moving mesh algorithms) via
video  astro  physics 
august 2012 by aries1988
CfA Press Room
One of Arepo's key advantages is the geometry it uses. Previous simulations divided space into a bunch of cubes of fixed size and shape. Arepo uses a grid that flexes and moves in space to match the motions of the underlying gas, stars, dark matter, and dark energy.

The simulations ran on Harvard's Odyssey high-performance supercomputer, using in total 1024 processor cores. This fast machine allowed the scientists to compress 14 billion years into only a few months - an endeavor that would have kept a desktop computer busy for hundreds of years!
simulation  astro 
august 2012 by aries1988
India’s Planned Mars Mission Receives Mixed Reactions | World | TIME.com
The country's planned mission to Mars has prompted strong reactions, particularly among those concerned about domestic issues on the ground
india  astro  nation  people 
august 2012 by aries1988
载人航天有什么用?
我的答案是:天下没有不蒙人的政治,但也许可以有不骗人的政治?如果你脸皮没有厚到去宣传太空实验、“太空育种”的程度,那就使劲宣传靠谱得多的“技术反哺社会”吧!比如观察者网上马平的文章《技术制高点必须自己爬》,就是这样的好宣传文章。
http://www.instapaper.com/read/299906600
thinking  nation  astro  debate  science  public  politics 
july 2012 by aries1988

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