Earth-like planets are fairly common in our Universe?

NASA's Kepler Mission that started three years ago has already discovered thousands of potential Earth-like planets, the so called exoplanets. This pioneer mission could hold great future importance as the astronomers look for new habitable planets outside our solar system.

It is very likely that one day space travel will be as common as taking a plane flight but prior to going further to space we need to gather as much of useful data as possible. As always, preparation is the key for successful travel, and in space travel even the small mistakes aren't allowed.

The NASA scientists have recently stated that „17 percent of all sun-like stars have planets one to two times the diameter of Earth orbiting close to their host stars.“ However, the current limitation of Kepler's detection capability suggests that this percentage could be lot bigger, some say even up to 50 percent.

The U.S. astronomer Andrew Howard from the University of Berkeley made the interesting observation by saying that „the frequency of planets increases as you go to smaller sizes, but it doesn't increase all the way to Earth-size planets as it stays at a constant level below twice the diameter of Earth“.

One other important fact is that planet doesn't have to be necessarily habitable just because it is one to two times the size of Earth and orbits around its Sun. Planets could turn out to be worlds with rocky core, similar to Uranus or Neptune, or could even turn out to be water worlds, covered with extremely deep oceans.

How does Kepler telescope work? In order to find planets, the Kepler telescope captures repeated images of 150,000 stars in a region of the sky in the constellation Cygnus, and afterwards the captured images are being analyzed by the advanced computer software.

Many astronomers believe it’s only a matter of time before new Superearth will be discovered. The road to space colonization is long and hard but the pioneering work of Kepler telescope will no doubt be forever remembered in the history of the human race.

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Huge stars in space - The biggest one yet

Today's astronomy news are all about scientists detecting the most massive star of all time, and they have named it R136a1, not very original name if I may add.

If you thought that our Sun is enormous you better think again because this star has a mass about 265 times that of our own Sun, and to make things even more interesting scientists believed that at the time when this star was born its mass was even bigger, at about 320 times that of the Sun's mass.

The biggest star in the universe - Our Sun looks so small compared to this massive star.

Professor Paul Crowther from UK's Sheffield University said that "if it (this star) replaced the Sun in our Solar System, it would outshine our Sun by as much as the Sun currently outshines the full Moon.

This star as many stars before them, and even more after them will one day explode as supernova to seed the Universe with heavy elements.

It is also very interesting to add that astronomers also detected several stars with surface temperatures over 40,000 degrees - more than seven times hotter than our Sun.

Scientists are also convinced that no planet can exist in orbit around such huge stars. Professor Crowther explained this on very funny way by saying that "planets take longer to form than these stars take to live and die, and even if there were planets, there would be no astronomers on them because the night sky would be almost as bright as the day in these clusters".

Previously observed huge stars had been seen to get as big as 150 times the mass of our Sun but these latest findings will no doubt raise interesting questions about upper limits of size these colossal stars have.

Many scientists support the theory that stars must have some physical barrier of their growth because their growth should come to a moment where the pressure from all the radiation emitted by a stellar behemoth pushes back against any further infall of gas and dust.

Most astronomers will agree that very early Universe has lots of these massive stars, and when these colossal stars blew apart, their cataclysmic demise was so violent they may not have left behind a remnant core of material as is often the case following a supernova; or even a black hole which is another common consequence, too. Instead, they simply have dumped all their contents back into space, dispersing heavy elements like iron equivalent to the mass of 10 of our Suns.

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Interesting science facts - Space & astronomy

Term "spacetime" was first used by Albert Einstein in his paper on a "Special theory of relativity", in which he proposed that space and time should be combined into a single construct known as "spacetime".

Word astronomy comes from two Greek words "astron" meaning star and "nomos" meaning law, and would basically mean law of the stars.

The defining feature of every black hole is the so called "event horizon". Event horizon is a surface in spacetime that marks a point of no return, and once an object crosses this surface, it cannot return to the other side.

In theory, there is no smallest size for a black hole.

Almost 90% of all the incoming cosmic ray particles are protons.

Dark matter is matter that is undetectable by its emitted radiation, and its presence can be inferred from gravitational effects on visible matter. The dark matter component has much more mass than the "visible" component of the universe.

Each galaxy consists of stars and stellar remnants, an interstellar medium of gas and dust, and dark matter. Dark matter account for around 90% of the mass of most galaxies.

There are probably more than 100 billion galaxies in the observable universe. Galaxies come in three main types: ellipticals, spirals, and irregulars.

Nebula is an interstellar cloud of dust, hydrogen gas and plasma. Some nebulae are formed as the result of supernova explosions.

Extrasolar planets, or sometimes called exoplanets are planets beyond our solar system, orbiting a star other than our Sun.

Big bang theory is the most common theory of Universe origin. According to this theory universe has expanded some 12-14 billions years ago from a primordial hot and dense initial condition at some finite time in the past, and continues to expand to this day.

Asteroids are space bodies primarily found in the inner Solar System — that are smaller than planets but larger than meteoroids, with the exclusion of comets.

Comets are small Solar System Bodies that orbit the Sun and once close enough to the Sun, exhibit a visible coma (atmosphere) or a tail — as a result of solar radiation upon the comet's nucleus.

Meteor is visible part of the meteoroid that enters Earth's atmosphere. Once meteor reaches the ground it is called a meteorite.

Jupiter is the largest planet within our Solar system, primarily composed of hydrogen with a small proportion of helium.

Saturn is the second largest planet in Solar system. It has unique system of surrounding rings, consisting mostly of ice particles with a smaller amount of rocky debris and dust.

Evidence suggests that planet Mars was once significantly more habitable than it is today, but whether living organisms ever existed there is still unclear.

Venus is the hottest planet in our solar system with surface temperatures of over 460 °C.

Until 2006 Pluto was considered as one of our solar system's planets, but since 2006 it is classified into new category called "dwarf planets".

Mercury is the smallest planet in our solar system, it is also planet the closest to Sun.

There are There are three main types of telescopes:

* The refracting telescope which uses lenses to form an image.
* The reflecting telescope which uses an arrangement of mirrors to form an image.
* The catadioptric telescope which uses mirrors combined with lenses—either in front of the mirror or somewhere within the optical path—to form an image.

Moon is the Earth's only natural satellite and the fifth largest natural satellite in the Solar System.

Millions of people worldwide believe they have seen UFOs, and tens of thousands of UFO reports have been cataloged.

Popular phrase "Houston we have a problem" comes from the words of Commander James A. Lovell, commanding officer at the infamous Apollo 13 who during the radio transmission with NASA said: "Houston, we've had a problem".

NASA (National Aeronautics and Space Administration) was established on July 29, 1958. NASA's headquarters is located in Washington, D.C.

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