[Luis França]

Space Cloud to Collide With Our Galaxy

Cosmic Cloud on Collision Course

AUSTIN, TEXAS--It's large, it's fast, and it's heading toward the Milky Way. Less than 40 million years from now, a giant cloud of hydrogen gas, clocked at 250 kilometers per second, will smash into our home galaxy, likely setting off a huge burst of star formation. In fact, the cloud contains enough gas to form a million stars like our sun, astronomers reported here today at the 211th meeting of the American Astronomical Society. The finding also indicates that pristine material is still entering the relatively mature Milky Way.

Many clouds of hydrogen surround the Milky Way. But astronomers didn't start spotting them until a half-century ago--after the advent of radio telescopes, which are able to detect cold, neutral hydrogen gas. The early observations were not accurate enough to determine the clouds' distances, masses, or directions of motion, however.


Source of Mysterious Antimatter Found



Antimatter, which annihilates matter upon contact, seems to be rare in the universe. Still, for decades, scientists had clues that a vast cloud of antimatter lurked in space, but they did not know where it came from.
The mysterious source of this antimatter has now been discovered — stars getting ripped apart by neutron stars and black holes.
While antimatter propulsion systems are so far the stuff of science fiction, antimatter is very real.

[Luis França]

Milky Way Has Mysterious Lopsided Cloud Of Antimatter: Clue To Origin Of Antimatter



ScienceDaily (Jan. 14, 2008) — The shape of the mysterious cloud of antimatter in the central regions of the Milky Way has been revealed by ESA’s orbiting gamma-ray observatory Integral. The unexpectedly lopsided shape is a new clue to the origin of the antimatter.

The new results give astronomers a valuable new clue and point away from dark matter as the origin of the antimatter. Beyond the galactic centre, the cloud is not entirely spherical. Instead it is lopsided with twice as much on one side of the galactic centre as the other. Such a distribution is highly unusual because gas in the inner region of the galaxy is relatively evenly distributed.

Equally importantly, Integral found evidence that a population of binary stars is also significantly off-centre, corresponding in extent to the cloud of antimatter. That powerfully suggests these objects, known as hard (because they emit at high energies) low mass X-ray binaries, are responsible for a major amount of antimatter.

[Luis França]

Ora vejam esta imagem captada pela Spirit (no original são 43mb - link [save link as]) que aparece nalguns jornais desta semana:

Faz-me lembrar "O Pensador" de Rodin...





THESE amazing pictures seem to prove something geeks and Sci-Fi fans have suspected for years - there's life on Mars.
Nasa's Mars Explorer Spirit sent us these images from the surface of the Red Planet four years ago.
After intense scrutiny, pictures that could be a living being have finally been found.
An amateur astronomer commented: "As far as I'm concerned, this is proof.
"What else could it be but a human-like creature?"
A pile of rocks, perhaps?

Pictures show life on Mars

[Luis França]

Spectacular Sky Show: Venus, Jupiter and the Moon



The most spectacular celestial sights over the next couple of weeks are reserved for the early morning sky. Two bright planets will converge, then be joined by the moon.
Such an eloquent description certainly fits our current morning sky, for these final days of January and the first days of February will be an exceptional time for predawn sky watchers with a beautiful pairing of the two brightest planets, Venus and Jupiter. They will appear closest together in the dawn sky of Friday, Feb. 1, and a few mornings later, the waning crescent moon will later drop by to join them.


Giant Particle Accelerator Discovered In The Sky



ESA’s orbiting gamma-ray observatory, Integral, has made the first unambiguous discovery of highly energetic X-rays coming from a galaxy cluster. The find has shown the cluster to be a giant particle accelerator.
The Ophiuchus galaxy cluster is one of brightest in the sky at X-ray wavelengths. The X-rays detected are too energetic to originate from quiescent hot gas inside the cluster and suggest instead that giant shockwaves must be rippling through the gas. This has turned the galaxy cluster into a giant particle accelerator.

[Luis França]

Space Weather Forecasts May Be Wiped Out In UK



The field of science dedicated to understanding "space weather" - which can pose hazards to satellites and aircraft - may be wiped out in the UK.

That is the verdict of experts responding to UK physics and astronomy cuts made as administrators seek to plug an £80m hole in their finances.
The UK is recognised as a world leader in solar-terrestrial physics (STP).
The science is crucial for protecting our communications networks against powerful outbursts from the Sun.
The organisation MIST (Magnetosphere, Ionosphere and Solar-Terrestrial) which represents the STP community in the UK, has issued a damning statement in which it says the cuts will prove catastrophic to this area of research.

[Luis França]

Acid House smiley face found on Mars



Astronomers have been having a funny time of it lately. We have had reports of Bigfoot (or possibly a Danish mermaid) on Mars, and a "spider" on the fiery planet of Mercury. You would be forgiven, therefore, for thinking the universe is laughing at us.
And it turns out you'd be right. The Sun newspaper reports that a satellite orbiting Mars has now spotted what looks suspiciously like a big smiley face drawn crudely onto the surface of the red planet.

[iceworld]

Post Original de Luis França

Acid House smiley face found on Mars



Astronomers have been having a funny time of it lately. We have had reports of Bigfoot (or possibly a Danish mermaid) on Mars, and a "spider" on the fiery planet of Mercury. You would be forgiven, therefore, for thinking the universe is laughing at us.
And it turns out you'd be right. The Sun newspaper reports that a satellite orbiting Mars has now spotted what looks suspiciously like a big smiley face drawn crudely onto the surface of the red planet.

Já fui lá fora sorrir lá para cima!! Espero que tenham aprendido o que é um grande sorriso.

[Luis França]

Mysterious Symbols Projected in Night Sky
by Aerial Disc Near Stephenville, Texas, Local Airport









David began running the camera at 10:10 PM Central, on Saturday, January 19, 2008, while standing on his home porch near the Stephenville local airport on the east side of town. David braced his arm and camera against a wooden post on the porch. The total videotape runs for nearly 12 minutes. Occasionally David's voice can be heard, so audio was functioning. But David told Steve Allen he could not hear any sound from the original disc that suddenly began projecting the colorful symbols that pulsed two per second, changing every 15 video frames. Thirty video frames equals one second.

[Luis França]

NASA plans to smash spacecraft into the moon

Scientists are priming two spacecraft to slam into the moon's South Pole to see if the lunar double whammy reveals hidden water ice.

The Earth-on-moon violence may raise eyebrows, but NASA's history shows that such missions can yield extremely useful scientific observations.

"I think that people are apprehensive about it because it seems violent or crude, but it's very economical," said Tony Colaprete, the principal investigator for the mission at NASA's Ames Research Center in Moffett Field, Calif.

Another planet may be beyond Neptune: researchers

Scientists concluded in 2006 that Pluto is too small to be defined as a planet, but a research group at Japan's Kobe University said Wednesday that their research indicates the possible existence of another solar system planet beyond Neptune.
The unidentified planet is likely to meet the definition of a planet in the solar system set by the International Astronomical Union in 2006, according to Tadashi Mukai, a professor at Kobe University's Graduate School of Science.
"We might well find it within a decade if we launch a large-scale study," said Mukai.
According to the research conducted by Mukai and Patryk Lykawka, the planet is about 30-70 percent of Earth's mass and located more than 12 billion kilometers from Earth.

[Luis França]

Wandering Poles May Explain Ups And Downs Of Ancient Mars Shoreline

A paper in this week's issue of Nature by University of California, Berkeley, geophysicists demolishes one of the key arguments against the past presence of large oceans on Mars. Even from Earth, a large plain surrounding the planet's north pole looks like a sediment-filled ocean basin. In the 1980s, Viking spacecraft images revealed two possible ancient shorelines near the pole, each thousands of kilometers long with features like those found in Earth's coastal regions.
In the 1990s, however, NASA's Mars Global Surveyor mapped the Martian topography to a resolution of 300 meters, and found that the shoreline varies in elevation by several kilometers (more than a mile), rising and falling like a wave with several thousand kilometers from one peak to the next. Because shoreline elevations on Earth, measured relative to sea level, are typically constant, many experts rejected the notion that Mars once had oceans.

UC Berkeley scientists have now discovered that these undulating Martian shorelines can be explained by the movement of Mars' spin axis, and thus its poles, by nearly 3,000 kilometers along the surface sometime within the past 2 or 3 billion years. Because spinning objects bulge at their equator, this so-called "true polar wander" could have caused shoreline elevation shifts similar to those observed on Mars.

"When the spin axis moves relative to the surface, the surface deforms, and that is recorded in the shoreline," said study coauthor Michael Manga, UC Berkeley professor of earth and planetary science.

"On planets like Mars and Earth that have an outer shell, or lithosphere, that behaves elastically, the solid surface will deform differently than the sea surface, creating a non-uniform change in the topography," added primary author Taylor Perron, a former UC Berkeley graduate student now a postdoctoral fellow in Harvard University's Department of Earth and Planetary Sciences.

[Luis França]

Japanese scientists eye mysterious 'Planet X'


This illustration released by Kobe University shows a planet -
- half the size of Earth -- which is believed to be in the outer
reaches of the solar system. The researchers at Kobe University
have said that their theoretical calculations using computer
simulations lead them to conclude it was only a matter of time
before the long-awaited "Planet X" was found.
Photograph by : AFP/HO

Kyoko Hasegawa , AFP
Published: Thursday, February 28, 2008

Scientists at a Japanese university said Thursday they believed another planet up to two-thirds the size of the Earth was orbiting in the far reaches of the solar system.

The researchers at Kobe University in western Japan said calculations using computer simulations led them to conclude it was only a matter of time before the mysterious "Planet X" was found.

"Because of the very cold temperature, its surface would be covered with ice, icy ammonia and methane," Kobe University professor Tadashi Mukai, the lead researcher, told AFP.

[Gilmet]

Deep Hole Found on Mars



A very dark spot on Mars could be an entrance to a deep hole or cavern, according to scientists studying imagery taken by NASA's Mars Reconnaissance Orbiter.

The geological oddity measures some 330 feet (100 meters) across and is located on an otherwise bright dusty lava plain to the northeast of Arsia Mons, one of the four giant Tharsis volcanoes on the red planet.

The hole might be the sort of place that could support life or serve as a habitat for future astronauts, researchers speculated.

Must be deep

The Mars Reconnaissance Orbiter (MRO) used its High Resolution Imaging Science Experiment (HiRISE) instrument to draw a bead on the apparent deep hole — a feature that may cause more scientists to ponder about potential subsurface biology on Mars.

Because the spot lacks a raised rim or tossed out material called ejecta, researchers have ruled out the pit being an impact crater. No walls or other details can be seen inside the hole, and so any possible walls might be perfectly vertical and extremely dark or — more likely — overhanging.

HiRISE image specialists said the pit must be very deep to prevent detection of the floor from natural daylight, which is quite bright on Mars.

In April, it was announced that the NASA Mars Odyssey and its Thermal Emission Imaging System (THEMIS) found near the equator seven dark spots that scientists think could be entrances to underground caves.

Meanwhile, MRO is ready to target the dark spots on Mars over the coming months as opportunities arise, explained HiRISE principal investigator, Alfred McEwen, of the University of Arizona in Tucson.

"We especially want oblique images from the west, to see illuminated walls. These are deep holes with overhanging walls, but perhaps not long caves," McEwen told SPACE.com.



Fonte: http://www.space.com/scienceastronom...mars_hole.html



Que coisa estranha, esta...

[Sueste]

Caros amigos do forúm,

Peço ajuda aos entendidos na matéria, para a seguinte questão:

À noite, perto das 21h +/-, vejo um ponto luminoso que se destaca no céu a sul. Será um planeta? Será que alguem me pode ajudar nesta duvida?

E já agora, onde posso encontrar informações sobre os planetas visiveis a olho nú no céu nocturno?


Obrigado pela vossa ajuda.

Cumprimentos

[Vince]

Post Original de Sueste

À noite, perto das 21h +/-, vejo um ponto luminoso que se destaca no céu a sul. Será um planeta? Será que alguem me pode ajudar nesta duvida?

Este é o mapa do céu para a Fuzeta às 20:00 UTC (21:00 PT) de ontem. Para sul não estou a ver o que seria assim de mais óbvio. Não seria Marte em WSW ?

Post Original de Sueste

E já agora, onde posso encontrar informações sobre os planetas visiveis a olho nú no céu nocturno?

Vai ao Heavens Above:
http://www.heavens-above.com/

Seleciona a tua posição por país/localidade na Base de dados, ou por coordenadas num mapa.
Se te registares (gratuito) não precisas de estar sempre a inserir a tua posição.

Uma vez escolhida a tua posição tens acesso a tudo, o mapa do céu (Whole sky chart) para a data/hora que quiseres, bem como as passagens da ISS, satélites, cometas, planetas, etc,etc e respectivos dados como a magnitude, etc.

[Sueste]

Obrigado Vince pela rápida resposta...

Se me permite, não é tão para W, mas sim S. Ao ver o mapa que me indicou, penso que seja Jupiter. Talvez a hora que indiquei não seja a mais correcta, pois podia ser mais perto das 22h.

Vou tentar pesquisar mais o tal site que me indicou.