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Système solaire

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PGJ - Date de Passage au périhélie des Comètes. Suivez le plongeon d’une comète vers le Soleil. Depuis quelques heures, l’observatoire spatial SOHO observe la vaporisation spectaculaire d’un noyau cométaire qui plonge vers notre étoile.

Suivez le plongeon d’une comète vers le Soleil

La comète fonce vers le Soleil (cercle blanc) dans le champ du coronographe LASCO C2 de la sonde SOHO (ESA/NASA). L’éclat éblouissant de notre étoile est occulté (disque rouge) ; sur le côté gauche, une éruption solaire est bien visible, elle n’est absolument pas provoquée par l’arrivée de la comète. Here's What The Sun Looks Like From Every Planet In Our Solar System. Our Solar System is a seriously beautiful place.

Here's What The Sun Looks Like From Every Planet In Our Solar System

Whether it’s the pockmarked volcanic surface of Mercury, the dusty crimson plains of Mars, the beautiful rings of Saturn, or even the blues and viridians of our own world, it’s a diverse place full of remarkable sights and natural wonders. We’d be nowhere without the Sun, mind you, and a series of truly stunning visualizations of our local star – as seen from each planet, and poor demoted Pluto – by artist and illustrator Ron Miller serve to remind you of this fact.

He’s spent more than 40 years illustrating the dark realms of space, both near and far, and has come up with the most realistic depictions of the Sun as seen from these far-flung worlds as possible. “I've taken care in not only making sure the Sun is depicted realistically, but also the surfaces of the planets and satellites as well,” Miller told IFLScience.

Thanks to the laws of physics, the brightness of the Sun is equivalent to the square of the relative distance from it. Système solaire. Tous sur Mars ! - L'Esprit Sorcier - Dossier #14. Regardez l’émission qui accompagne ce dossier : L’aventure martienne Retrouvez toutes nos vidéos sur la chaîne Youtube de l’Esprit Sorcier Suivez-nous sur Facebook et Twitter Soutenez-nous sur Tipeee !

Tous sur Mars ! - L'Esprit Sorcier - Dossier #14

Un dossier préparé parBarbara Gineau Delyon Rédaction en chef Frédéric Courant Direction artistique et technique Pascal Léonard Direction de productionJoël Guillemet Assistante de réalisationAnaïs Van Ditzhuyzen Assistant de productionPatrick Berger Documentaliste Laurence Lebon Montage/Prise de vueTimothée Coignus. Construction d'un système stellaire ; vitesse+distance+masse modulables. Animation Système Solaire - P. Cosentino. Earth Blamed for Cracks in Moon. Photo The moon is shrinking, and is to blame for how the ’s crust has cracked.

Earth Blamed for Cracks in Moon

Scientists reported the shrinkage in 2010, when researchers, led by Thomas R. Watters of the Smithsonian’s National Air and Space Museum, picked out cracks in images taken by ’s Lunar Reconnaissance Orbiter. They counted 14 ridges, formed when one side of the fracture slips over the other, but the orbiter’s high-resolution camera had covered only about 10 percent of the moon’s surface. Five years later, more than three-quarters of the surface has been photographed, and the scientists now count more than 3,200 ridges, most quite small — less than six miles long and tens of yards high. If the moon were shrinking uniformly, then the cracks and ridges should be pointed every which way.

What they figured out is that the tidal forces of the Earth pulling on the moon, while small, generated enough stress to break the moon’s crust in the observed pattern. To Scale: The Solar System. P/1999 R1 (SOHO) at perihelion, September 2015 – Comet P/1999 R1 (SOHO) will make its closest approach to the Sun, at a distance of 0.05 AU.

P/1999 R1 (SOHO) at perihelion, September 2015 –

From Ottawa (click to change) however, it will not be readily observable since it will be very close to the Sun, at a separation of only 2° from it. For more information about its path across the sky, see's ephemeris page for comet P/1999 R1 (SOHO). This event was automatically generated on the basis of orbital elements published by the Minor Planet Center (MPC), and is updated daily (last update, 11 Sep 2015). Note that the future positions of comets are typically known with a high degree of confidence, but their brightnesses are often much more unpredictable, since it is impossible to predict with certainty how they will respond as they move closer to the Sun.

Magnitude estimates should be assumed to be highly provisional more than a few weeks in advance. The exact position of comet P/1999 R1 (SOHO) will be: The coordinates are given in J2000.0. Preds15.pdf. Comet observations table. 2015 August 18 - Announcing Comet Catalina. Discover the cosmos!

2015 August 18 - Announcing Comet Catalina

Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2015 August 18 Explanation: Will Comet Catalina become visible to the unaided eye? Given the unpredictability of comets, no one can say for sure, but it seems like a good bet. The comet was discovered in 2013 by observations of the Catalina Sky Survey. What's Up in Space: Comet Catalina previews a bright future. Scott Sutherland Meteorologist/Science Writer Wednesday, August 19, 2015, 3:02 PM - A celestial wanderer gives us a preview of a potentially bright future, a violent origin for one of Saturn's rings and The Martian visits NASA's Jet Propulsion Laboratory.

What's Up in Space: Comet Catalina previews a bright future

It's What's Up In Space! Comet Catalina glows green A first-time visitor to the solar system is getting closer to its one-and-only swing by the inner planets, and even though it's still farther away from the Sun than the planet Mars, it is already showing up beautifully in telescopes. Kepler-452b, une cousine de la Terre à 1400 années-lumière. La Nasa vient d'annoncer la découverte d'une exoplanète de 1,6 rayon terrestre située dans la zone habitable d'une étoile comparable au Soleil.

Kepler-452b, une cousine de la Terre à 1400 années-lumière

La zone habitable est la région ni trop proche ni trop éloignée, autour d'une étoile, où la température à la surface d'une planète permet la présence d'eau liquide. Si les propriétés de Kepler-452b sont encore trop floues pour estimer sa composition (sa masse, notamment, est inconnue), il s'agit tout de même, avec Kepler-186f, d'une étape intéressante vers la découverte d'une « Terre 2.0 ». Clin d'œil stellaire Kepler-452b a été découverte par le satellite américain Kepler par la méthode dite « des transits ».

Space Images.