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Mysteries of the Universe

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Moons of the planets
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Matter and particles
Light and photons
Earth
Planets and dwarf planets
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Stars
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Probes and satellites
Galaxies
Black holes
Exoplanets
Nebulas
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Hubble images
Signs of the Zodiac
Universe
Astronomy for children
Rosetta et Philae November 12, 2014: For ten years, Rosetta and Philae traveled together to reach their destination...
   
MOM Indian spacecraft October 24, 2014 : MOM is the first Martian spacecraft developed by India, a real feat of ISRO (Indian Space Agency)...
   
Chariklo asteroid and its amazing rings March 28, 2014 : The planetoid Chariklo (10199) is also a centaur asteroid about 250 km in diameter particularly surprising, it has 2 rings.
   
BICEP-2 to search for gravitational waves March 16, 2014: BICEP-2 to search for gravitational waves. What is a gravity wave?
 
Rosetta and the comet  January 20, 2014: Rosetta, beyond the orbit of Jupiter, has a rendezvous with Comet Churyumov-Gerasimenko.
   
simulator planets orbit Online simulator.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Saturn from all angles with the Astronoo simulator.
   
diable de poussière sur Mars Unusual images of astronomy.
"It's better to see once than hear a hundred times."
 

Astronomy - The curiosity that characterizes humanity, has enabled man to understand the major astronomical phenomena and it now gives a dramatic sense stronger what is happening before our eyes.
At the heart of a nebula of gas and dust, the gravitational pressure and heat will initiate nuclear reactions. A star is born and around the system, revolve planets, asteroids, comets, small objects, gas and residual dust. The matter is organized around the universe in the same way and nevertheless the diversity of objects and stellar systems is surprising. The dust are the building blocks of planets, they stick together to form small bolides, that collision in collision form objects, which grow to the detriment of their neighbors.

 

Their masses and gravity increase, attracting themselves more matter. Collisions liberate large amounts of heat, the atoms disintegrate themselves and expect cooling to assemble molecules.
On a stable planet, much later, there will be assembly of simple molecules and complex molecules to reach this wonderful DNA molecule will now reproduce and store information, opening the way for biological evolution that we know.

« It is entirely possible that behind the perception of our senses, worlds are hidden of which we are unaware. »
Albert Einstein (1879-1955), Nobel Prize in Physics in 1921 for his interpretation of the photoelectric effect.

 
 

World population...

GAIA satellite, mapping the Milky WayQuantum tunneling of quantum mechanics
GAIA satellite
mapping the Milky Way...
Quantum tunneling of
quantum mechanics...
  
Disaster of great eruptionImage of pure gold atom seen by Scanning Tunneling Microscope
Super eruption or
global catastrophe...
Closer to the matter
image of the atom...
  
entropy effects, the passage of TimeSouth Atlantic Anomaly (SAA)
The passage of Time...
South Atlantic
Anomaly (SAA)...
  
Impact craters on EarthSpectroscopy, emission lines, absorption lines
Impact craters
on Earth
Spectroscopy inexhaustible
source of information...
12 particles of matter and bosonsThe problem of the rotation curve of a galaxy
12 particles of matter...MOND theory
and its contradiction...
atomic orbitals or electronic orbitalsEclipses, the orbital plane of the Moon
The atomic orbital
or image atom...
Eclipses explained by
plan lunar orbit...
 
Apophis, the next disasterearthshine from the Moon
Apophis,
the next disaster...
Earthshine,
evidence of the life...
  
Atomic clock fountain of cesium atomsChimborazo volcano in Ecuador, the highest mountain of the world
The incredible precision
of the second...
Chimborazo, highest
mountain of the world...
  
Bioluminescence of living organismsAberration of light
Bioluminescence of
living organisms
Effects of aberration
of light...
  
Merope nebula IC 349 and stellar windsPluton and its satellites
Stellar winds of
the Merope nebula...
Pluto system...
bullet cluster and dark matterPrinciple of absorption and emission of a photon
Bullet cluster,
evidence of dark matter...
Principle of atomic
absorption and emission...
Cycle de Saros et ExeligmosSensitivity to initial conditions, lorenz attractor
Saros cycle
and Exeligmos...
Chaos and sensitivity
to initial conditions...
 
Thème de la semaine

Exoplanets

Exoplanets are by definition located outside our solar system. The search for extrasolar planets is a real challenge for humanity, the underlying question that scientists are trying to answer is "are we alone in the Universe?".
Since the first discovery of extrasolar planets in 1995 (51 Pegasi b), a large number of space projects such as HARPS (2003), CoRoT (2006), Kepler (2009), JWST (2018) to Darwin (2020) have obtained funding.
Until 2020, the methods used to find exoplanets, are indirect methods (effect of transit effect on the radial velocity, microlens effect ...), that is to say that exoplanets are detected only by the effects that it induces on their star. But from 2020, with the DARWIN space project, all humanity will see an extrasolar planet directly and perhaps a exoterre.
How to detect exoplanets?
Transit (periodic micro-eclipse) occurs every time the planet passes between the star and the observer. At that time, the planet obscures some of the light from the star, producing a detectable periodic dimming. This remarkable idea is used to detect the planet and directly determine its size and its orbit. The diameter of Jupiter is 10 times smaller than the Sun, Jupiter mask so 1% of the luminosity of the Sun as it passes in front of a distant observer. Earth it is 100 times smaller than the Sun, so do mask 1/10000th of its brightness.
How to see exoplanets?
With Darwin, we'll see the planet or rather its atmosphere that reflects light from its star. Any light that is perfectly aligned with the telescopes (that of the star) will be extinguished and so the planet can be seen without being dazzled by the nearby star.
What are the biosignatures that will reveal the presence of life on distant exoplanets?
By analyzing the spectrum of light from the atmosphere of a planet, it is possible to detect the presence of chemical compounds such as carbon dioxide (CO2), water (H2O), ozone (O3), oxygen (O2) or other ionic assembly, and therefore no organic compounds based on a carbon skeleton. CO2 in large quantities and the water would be the signature of photosynthetic activity. Oxygen has a specific feature. This aggressive atom may not remain in a gaseous envelope around a planet because it binds very easily with metals and rocks, to make oxides. If there is oxygen in quantity around a planet that means biotic phenomena exist.
 
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L'astronomie pour les enfants
Astronomy for children...
 
Simulator, rotation and position of the planets (dynamic graphic)
Simulator, the
revolution of the planets...
 
Simulator revolution and orbits of asteroids
Simulator the round
of asteroids...
 
Definition of astronomical terms in SMS format
Astronomical terms
in SMS format...
 
 
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