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An image released shows a huge moving cloud almost half the size of United States over Titan’s northern pole. This cloud is made up of ethane, methane, and other organic material which could be a source of methane lakes spotted near the pole last summer.

NASA’s Cassini spacecraft captured this image of the 1,490-mile-diameter (2,400-kilometer-diameter) cloud on December 29, 2006. The cloud’s presence fits predictions that the Titan has a “methane cycle” which is similar to Earth’s water cycle, with bodies of liquid methane evaporating and forming clouds that causes rain.

The cloud system changes position according to the moon’s seasons, experts predict, and it will eventually migrate from the north pole to the south pole.

Ground-based observations suggest that the total cloud activity on Titan will last for about 25 years, then vanishes for a 4- to 5-year period. The massive cloud over the pole should be around for some more years before it disappears.

The Hubble Space Telescope is still proving helpful, they are capturing a new round of amazing pictures with its camera. NASA released new pictures of a dying star a white dwarf that is shown in the form of a bright dot at the center of nebula NGC 2440—that was once similar to the sun.

Low- to medium-size stars like the sun usually end their life as white dwarfs. Once most of a star’s hydrogen gets converted to helium, the star enters the red giant phase, finally throwing the outer material to form a nebula of stellar debris. The hot core left behind is called a white dwarf.

Spied by the telescope’s Wide Field and Planetary Camera 2, this white dwarf is 4,000 light-years away from the Earth. It is also one of the hottest known, with a surface temperature of around 400,000°F (200,000°C).

Ultraviolet light that comes from the dying star is what light’s up the gaseous matter that gets cast off from the star’s core. Our sun will also burn out and become a white dwarf surrounded by a vivid nebula but this will not happen for another five billion years.

It seems that nature is going through desperate times that are calling for desperate measures. According to experts, global warming can be tackled with a giant dust cloud that will be placed in space to block out the sun.

The sun shield made with the dust mined from the moon is the idea Curtis Struck at Iowa State University conceived in Ames and will be used only if the governments fail to tackle the greenhouse effect.

These lunar dust particles(the picture shows moon dust) are the right size that helps in scattering sunlight, Struck says. If these particles are injected at two precise positions along the moon’s orbit, they will form a pair of stable clouds that would pass in front of the sun at least once in a month, blocking the sunlight for around 20 hours every month.

“If we’re facing real threats to civilization, then you might resort to this sort of thing,” says Struck.

The others have criticized this theory on the basis that the clouds may reflect extra light onto the Earth during this time when they are not directly in front of the sun. Struck also says that even if more light is reflected, there would still be an overall decrease in the amount of sunlight reaching Earth.

Usually there is no worry of getting blind when looking at comets passing close to Earth. But according to astronomers that can happen if people are not careful when they look at the sky to get a glimpse of “comet McNaught”.

The comet was visible in the Southern Hemisphere near the horizon from dawn to dusk. It passed very close to the sun, so many of the observers are being cautioned not to look directly at the rising or setting of the star.

This fiery apparition that was seen in the morning through a gap in the clouds above Christchurch, New Zealand is claimed to be the brightest comet seen in 40 years. Because of this, the officials trained the crowds to look at the comet in a safe way.

The Australian astronomer Robert McNaught had seen the comet last August through a telescope at Siding Spring Observatory in New South Wales, Australia. This celestial body’s orbit was close to the sun and thus became visible to the eye in the northern hemisphere.

McNaught has had the nearest brush with the sun and became visible only to Southern Hemisphere sky-watchers. This comet is right now, 6.2-mile-wide (10-kilometer-wide) comet and is around 74.5 million miles (120 million kilometers) away from Earth and is traveling at around 62 miles (100 kilometers) a second. This once-in-a-lifetime view will be available for a few more days.

Black diamonds that are seen only in few places on Earth may have crashed down from space in a kilometre-sized rock, according to new research.These diamonds are also called as carbonado, and are only found in Brazil and the Central African Republic. Unlike the other diamonds, they are made of millions of diamond crystals that get stuck together.

They are also porous, which is still a puzzle. Scientists say it would have been difficult for gas to get trapped in rocks at depths of around 200 kilometres below the Earth’s surface. This extreme pressure under the earth turns carbon into normal diamonds.

“This is the feature that first led some of us to think, well, perhaps there has to be a different alternative,” says Stephen Haggerty, a geologist at Florida International University in Miami, US, and an author of the new study.

Because usually this kind of diamonds are rare and can never be found in traditional diamond fields, some scientists suspect that they crash to Earth from space.Researchers claim that this might have came from a large, diamond-bearing asteroid that may have fallen to Earth many billions of years ago, when the planet and the Moon were being heavily hit by space rocks.

This Carbonado has been dated to be between 2.6 billion and 3.8 billion years old. The researchers believe that the diamond is ancient, they also found hydrogen in the carbonado that indicates that the diamonds came from a hydrogen-rich interstellar space. The diamond dust from which they formed were released when a star exploded in the supernova many billions of years ago.

The diamond dust then became part of the cloud of gas and dust from which our solar system condensed. Over time, it coalesced into larger clumps that became embedded in asteroids “like plums in pudding”, Haggerty says.

The recent discoveries made around the past two years almost doubled the number of neighbors in the Milky Way. Seven of the newly discovered galaxies are in the Milky Way, at a distance of around 100,000 to 700,000 light-years away from earth, according to Daniel Zucker, an astronomer at the University of Cambridge in England.

The new dwarfs are extremely faint and diffuse and contain at most a few million stars each, Zucker noted. In fact, they are so small that he suggested calling them “hobbit galaxies.” The Milky Way, where these dwarf orbits have been found contain around 200 billion stars.

Zucker said that the present theories of galaxy formation and the mysterious substance known as dark matter say that the Milky Way could have around hundred or more surrounding dwarfs, but till the past few years only 12 of them have been known. These newly detected galaxies were found as part of the Sloan Digital Sky Survey, a project to create a high-resolution map of more than a quarter of the sky.

Eighth Dwarf

The eighth dwarf galaxy is located roughly around 1.4 million light-years away and is more exciting.

“It is far enough from the Milky Way that it has probably not really been affected much by the Milky Way’s gravity,” he said. “It’s actually free floating.” “This is basically the smallest, faintest, star-forming galaxy known by orders of magnitude,” Zucker said.

More to go?

There are many more such galaxies existing around the universe. When the first few stars were found it was a surprise, but soon it was realized that there were many others that were present perhaps even in dozens.