Moon to Make Last Appearance Until 2033

A rare astronomical phenomenon Sunday night will produce a moon that will appear slightly bigger than usual and have a reddish hue, an event known as a super blood moon.
It’s a combination of curiosities that hasn’t happened since 1982, and won’t happen again until 2033. A so-called supermoon, which occurs when the moon is closest to earth in its orbit, will coincide with a lunar eclipse, leaving the moon in Earth’s shadow. Individually, the two phenomena are not uncommon, but they do not align often.
Most people are unlikely to detect the larger size of the supermoon. It may appear 14 percent larger and 30 percent brighter, but the difference is subtle to the plain eye. But the reddish tint from the lunar eclipse is likely to be visible throughout much of North America, especially on the East Coast.

“You’re basically seeing all of the sunrises and sunsets across the world, all at once, being reflected off the surface of the moon,” said Dr. Sarah Noble, a program scientist at NASA.

Stargazers are excited. Though the celestial show will be visible by simply looking toward the sky, the Intrepid Museum in New York will host a free viewing from its perch at Pier 86 on the Hudson River with astronomers and high-powered telescopes on hand. The Amateur Astronomers Association of New York will be holding several free events in the city, including at the High Line, offering telescopes and binoculars for better views.

“People can ask questions, and we can answer the questions right there,” said Marcelo Cabrera, the club’s president.

The eclipse will begin at 9:07 p.m. Eastern time, as the Earth’s shadow moves across the moon, according to the association. At 10:11 p.m., the entire moon should be in the Earth’s shadow, at which point it will adopt the reddish color. It will remain fully in the shadow until 11:23 p.m., and the eclipse will end at 12:27 a.m.

If time or attention spans run short, Mr. Cabrera suggested looking up just before the moon descends fully into the Earth’s shadow at 10:11 p.m., as it turns color.

Dr. Noble said such events tend to get more people interested in astronomy, as it creates an opportunity to take children outside and get them looking up at the sky. “It leads to conversations about what else is up there,” she said.

Source:http://www.nytimes.com/2015/09/26/science/super-blood-moon-to-make-last-appearance-until-2033.html

What’s the deal with Antarctica and the Arctic? by NASA

writen by Laura Faye Tenenbaum a science communicator at NASA’s Jet Propulsion Laboratory and teaches oceanography at Glendale Community College.

NASA

Most people I meet don’t spend much time thinking about the polar regions on planet Earth; the poles just seem too far away. I mean, Antarctica, really? Only extreme explorers and a few scientists spend time thinking about those frozen places. Most of us live in areas with moderate temperatures, fantasize about tropical vacations and have barely checked out what the far reaches of our planet look like on a map. And even maps neglect the far north and south by stretching them so much that many people have no real idea what the ends of the Earth look like.

I became interested, and then obsessed, with Earth’s icy regions during a particularly hot Los Angeles summer a couple of years ago when I createdNASA’s Global Ice Viewer. Sitting in my office scouring NASA vaults for the most intriguing views of our planet’s ice was like going on a wild interstellar journey to someplace beyond my wildest imagination; it changed my view of our planet forever.

These days, I frequently give public speeches and show audiences what the Arctic and Antarctic look like from space. It surprises me how little people know about these portions of our world. Perhaps their biggest misunderstanding is that the Arctic and Antarctic are similar. You know, one’s in the north and the other is in the south; but other than that, they’re the same, right? No, this couldn’t be more wrong. These polar opposites are literally polar opposites.

For starters, the Arctic is a small, shallow ocean surrounded by land: Eurasia, Greenland, Canada and the United States. It’s only about 5 ½ million square miles, which is five times smaller than the Atlantic and 11 times smaller than the Pacific. Antarctica, on the other hand, is a continent surrounded by the entire Southern Ocean.

This may seem like no big deal, but it makes all the difference in the world. It takes a lot of energy to change water temperature compared to what it takes to change land temperature, which means Arctic seawater isn’t as cold as the continental ice sheet covering Antarctica. So, the Arctic sea ice (frozen sea water) is about 10 feet thick, whereas the Antarctic ice sheet (compacted freshwater ice) is over a mile thick.

In the winter, the Southern Ocean around the Antarctic continent also becomes covered with sea ice. But every summer most of this sea ice melts. That’s because the ice edge around Antarctica is exposed to open ocean, and every direction you go is north. So, during the summer, the sea ice moves north and melts away. This means that very little Antarctic sea ice is more than two years old. But Arctic sea ice is trapped inside the landlocked ocean. This means that during the summer months, even though much of the sea ice melts, it doesn’t melt completely.

More than opposites

Is this complicated enough? Consider one more comparison: The amount of Arctic sea ice is way down, while the amount of Southern Ocean sea ice is up by a tiny bit. If you’ve been reading closely, by now you’ll know that those two types of sea ice are probably super duper different because, yup, you guessed it: The two poles are much more than opposites.

Since 1979, NASA satellite measurements have observed an overall decline in Arctic sea ice due to climate change. Climate change warms the ocean water and melts the sea ice. Climate change has also caused some of the Antarctic ice shelves (which are part of Antarctica’s fresh water ice sheet that extends into the ocean, surrounding the continent) to collapse.

But the story of the sea ice floating around Antarctica in the Southern Ocean is even more complex. This sea ice is not just frozen seawater, like the Arctic sea ice. There’s more snow in the Southern Ocean — that ice is made of sea ice, covered by snow ice (frozen snow), covered by snow. It’s a snowman ice cream sandwich! And the strong winds down there easily blow this mixture across an expanding area.

The fact that our Earth is a crazy complicated place makes it difficult to understand, but that same truth also makes it amazing. Earth is never boring, which is why we keep paying attention to and never tire of learning more about it.

Test how much you know and learn more about Earth’s frozen places with these fun quizzes:

source: climate.NASA.gov

Analyse de la planète Vénus

Pendant que les USA étudiaient Mars, la Russie en 1970 ont envoyé Vénéra 7 une sonde russe vers Vénus pour l’étudier.

Elle fut le premier engin à atterrir sur le sol vénusien.

Le 27/03/1972, sonde Venera 8, URSS. Elle mesure les variations de vitesse des vents vénusiens.

Le 8/06/1975, sonde Venera 9, URSS. Elle photographie les nuages de Vénus.

Le 14/06.1975, sonde Venera 10, URSS. Elle photographie les nuages de Vénus.

Le 20/05/1978, sonde Pioneer Vénus 1, USA. Premier engin à utiliser le radar pour prendre des images de la surface vénusienne.

Le 08/08/1978,Pioneer Vénus 2, USA. Analyse atmosphérique et la sonde se consume dans la haute atmosphère.

Par la suite, URSS: Venera 11, 12, 13, 14, 15, 16. Vega 1 et Vega 2 de 1977 à 1984.

Plus tard, La sonde Magellan, appelée aussi le radar Mapper Vénus, était un 1035-kg (£ 2,282) robotique sonde spatiale lancée par la NASA le 4 mai 1989, avait pour mission de cartographier la surface de Vénus en utilisant un radar à synthèse d’ouverture et de mesurer le planétaire champ gravitationnel.

La sonde Magellan était la première mission interplanétaire à être lancé à partir de la navette spatiale, le premier à utiliser l’ inertie étage supérieur booster pour le lancement, et le premier vaisseau spatial pour tester aérofreinage comme méthode de circularisation de son orbite. Magellan était le quatrième succès de la NASA mission vers Vénus, et il a fini un écart de onze ans dans des États-Unis lancements de sondes interplanétaires.

Le 9 novembre 2005, une sonde russe a été lancée, sa mission, franchir des millions de kms pour trouver l’énigme de Vénus.

Huit sondes interplanétaires russes seront lancées jusqu’en 2020.

La sonde Venera-D, sera lancée vers Vénus en 2016.

Sa mission consistera à prendre des photos de la surface de la planète, à faire l’étude de la composition chimique de son atmosphère et son activité sismique.

Egalement la température et la pression qui y règnent seront mesurées.

Vénus-Étoile du Berger, un petit aparté, par Nathalie Lacladère

Vénus-Étoile du Berger est la seconde planète du système solaire. Un important effet de serre y fait régner une chaleur torride, de 470°C en moyenne. Suffisant pour faire fondre du plomb. Outre quelques plaines, dépressions et monts, dont le mont Maxwell qui culmine à 11 000 mètres, la planète est sous le sceau du volcanisme, avec plusieurs dizaines de milliers de volcans.

L’atmosphère de Vénus est principalement composée de dioxyde de carbone, avec un peu d’azote et des traces d’autres composés. La quantité d’azote dans l’atmosphère est relativement faible par rapport à la quantité de dioxyde de carbone, mais puisque l’atmosphère vénusienne est plus épaisse que l’atmosphère terrestre, la quantité d’azote totale est quatre fois supérieure à celle de la Terre (où l’azote représente 78% de l’atmosphère).

Le Maat Mons est le plus haut volcan de Vénus, c’est son bouclier.
Point culminant: 8 km
Dimensions caldeira: 31×28 km
Diamètre: 395 km

Il est à l’origine de la présence du méthane CH4 dans l’atmosphère de Vénus.

162804main_Magellan_venus

Le Maat Mons Bouclier sacré de Vénus-Etoile Du Berger

Transit de Vénus Étoile du Berger, le 5-6 juin 2012, par Nathalie Lacladère

Le 5-6 juin 2012 Vénus-Etoile du berger est passée devant le Soleil durant 6h51 dans la région de l’Asie-Pacifique et s’est achevée à 6h55 heure française.

En France, Vénus-Etoile du Berger était visible le mercredi 6 juin 2012 entre 5h50 et 6h55.

Pour regarder ce magnifique phénomène voici le lien NASA / SDO Vénus Transit.

Prochain Transit en 2117 pour les prochaines générations.

Très bonne journée à vous,

Très cordialement,
Vénus-Étoile du Berger