An artist's illustration of an Earth-like planet. The search for planets that are similar to Earth is one of NASA's main goals. Many planets have already been discovered orbiting other stars, but so far only larger planets (the size of Jupiter or larger) have been found. New missions are being planned by NASA which will be able to detect smaller Earth-sized planets. Some of these missions will also try to detect signs of life on these planets by studying emissions in their atmospheres.


Odds of Life on Newfound Earth-Size Planet '100 Percent,' Astronomer Says

29 September 2010

An Earth-size planet has been spotted orbiting a nearby star at a distance that would makes it not too hot and not too cold — comfortable enough for life to exist, researchers announced today (Sept. 29).

If confirmed, the exoplanet, named Gliese 581g, would be the first Earth-like world found residing in a star's habitable zone — a region where a planet's temperature could sustain liquid water on its surface. [Illustration of planet Gliese 581g.]

And the planet's discoverers are optimistic about the prospects for finding life there.

"Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say, my own personal feeling is that the chances of life on this planet are 100 percent," said Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz, during a press briefing today. "I have almost no doubt about it."

Read the full story here:

For more information:

New Earth-like planet discovered
Gliese 581g is in the 'Goldilocks zone' of its solar system, where liquid water could exist, and is a strong contender to be a habitable world

Earth-Like Planet Can Sustain Life
Located in a solar system that parallels our own, the new world could be habitable -- or even inhabited.

New Planet: There's Life! See Video!
Michio Kaku: Earth-Like Planet Discovered See Video!
Newly discovered planet to save human race See Video!

To learn more about: Gliese 581 Solar System.


Can We Spot Volcanoes on Alien Worlds? Astronomers Say Yes

SOURCE: Harvard-Smithsonian Center for Astrophysics
September 07, 2010

Cambridge, MA - Volcanoes display the awesome power of Nature like few other events. Earlier this year, ash from an Icelandic volcano disrupted air travel throughout much of northern Europe. Yet this recent eruption pales next to the fury of Jupiter's moon Io, the most volcanic body in our solar system.

Now that astronomers are finding rocky worlds orbiting distant stars, they're asking the next logical questions: Do any of those worlds have volcanoes? And if so, could we detect them? Work by theorists at the Harvard-Smithsonian Center for Astrophysics suggests that the answer to the latter is a qualified "Yes."

"You would need something truly earthshaking, an eruption that dumped a lot of gases into the atmosphere," said Smithsonian astronomer Lisa Kaltenegger. "Using the James Webb Space Telescope, we could spot an eruption 10 to 100 times the size of Pinatubo for the closest stars," she added.

Read the full story here:


706 Earthlike Planets Discovered By NASA Spacecraft‏

18 June 2010

NASA's Kepler spacecraft hunting for Earth-like planets around other stars has found 706 candidates for potential alien worlds while gazing at more than 156,000 stars packed into a single patch of the sky.

If all 706 of these objects pass the stringent follow-up tests to determine if they are actually planets, and not false alarms, they could nearly triple the current number of known extrasolar planets. They were announced as part of a huge release of data from the mission's first 43 days by NASA's Kepler science team this week.

The Kepler space observatory monitors stars for subtle changes in their brightness, which could indicate the presence of alien planets passing in front of them as seen from Earth. Astronomers will use the newly-released data from Kepler to determine if orbiting planets are responsible for the variation in brightness of several hundred stars.

Read the full story here:

For more information:

Millions of Earths? Talk causes a stir See Video!
A World of Difference between 'Earth-Like' and 'Earth-Sized'
140 Earth-like planets discovered in the Milky Way by Kepler See Video!
Dimitar Sasselov: How we found hundreds of Earth-like planets See Video!


NASA's Kepler Space Telescope Discovers Five Exoplanets

January 04, 2010

PASADENA, Calif. -- NASA's Kepler space telescope, designed to find Earth-size planets in the habitable zone of sun-like stars, has discovered its first five new exoplanets, or planets beyond our solar system.

Kepler's high sensitivity to both small and large planets enabled the discovery of the exoplanets, named Kepler 4b, 5b, 6b, 7b and 8b. The discoveries were announced Monday, Jan. 4, by members of the Kepler science team during a news briefing at the American Astronomical Society meeting in Washington.

"These observations contribute to our understanding of how planetary systems form and evolve from the gas and dust disks that give rise to both the stars and their planets," said William Borucki of NASA's Ames Research Center in Moffett Field, Calif. Borucki is the mission's science principal investigator. "The discoveries also show that our science instrument is working well. Indications are that Kepler will meet all its science goals."

Read the full story here:

For more information:

The First Five Worlds of Kepler See Video!
Searching for Alien Earths: The Kepler Space Telescope


Earth-like planets could be found soon: astronomers

January 8, 2010

Astronomers say they are on the verge of finding planets like Earth orbiting other stars, a key step in determining if we are alone in the universe.

A top NASA official and other leading scientists say that within four or five years they should discover the first Earth-like planet where life could develop, or may have already. A planet close to the size of Earth could even be found sometime this year if preliminary hints from a new space telescope pan out.

At the annual American Astronomical Society conference this week, each discovery involving so-called "exoplanets" — those outside our solar system — pointed to the same conclusion: Quiet planets like Earth where life could develop probably are plentiful, despite a violent universe of exploding stars, crushing black holes and colliding galaxies.

NASA's new Kepler telescope and a wealth of new research from the suddenly hot and competitive exoplanet field generated noticeable buzz at the convention. Scientists are talking about being at "an incredible special place in history" and closer to answering a question that has dogged humanity since the beginning of civilization.

"The fundamental question is: Are we alone? For the first time, there's an optimism that sometime in our lifetimes we're going to get to the bottom of that," said Simon (Pete) Worden, an astronomer who heads NASA's Ames Research Center. "If I were a betting man, which I am, I would bet we're not alone — there is a lot of life."

Read the full story here:
Astronomers: We could find Earth-like planets soon


Our Milky Way Galaxy

This is our home galaxy called "Milky Way" This arrow shows us where our sun is in the galaxy.

The Milky Way is a galaxy that contains at least 200 billion stars and their planetary systems. It is an average-size galaxy of the barred spiral class. This means that there is a central bulge, with arms, which extend for several light-years*. However, the term "barred" means that its central bulge is elongated; in the Milky Way, this elongation is at a ratio of 2:3, meaning that it is about one and a half times as long as it is wide.
The Milky Way has five distinct arms protruding from the central bulge. Their names are as follows: the Cygnus Arm, Centarus Arm, Sagittarius Arm, Orion Arm, and Perseus Arm. Our solar system lies in the Orion Arm.
The Milky Way belongs to a group of galaxies that is known as the Local Group. The Local Group contains about 30 galaxies, two of which are the Andromeda Galaxy and the Triangulum Galaxy. The Local Group is 9 million light-years in diameter.
In turn, the Local Group belongs to a much larger group of galaxies which known as the Virgo Supercluster. The Milky Way lies on the outer edge of the supercluster. The Virgo Supercluster is about 100 million light-years in diameter.
The Milky Way is 100 thousand light-years in diameter. The Milky Way takes approximately 225 million years to rotate, clockwise, even though the arm that we are in is whipping around the center at about 465,000 miles an hour. At that speed, a space ship from Earth would only need a half an hour to get to the moon!

This image is of the night sky the Milky Way Galaxy.
When we look up at the night sky we can see part of the Milky Way galaxy stretching across the night sky even though we are part of the Milky Way. That is because we are located at one small part of the Milky Way Galaxy and from our position we can see the dense cloud of stars formin another piece of the Milky Way.

  Properties of the Milky Way
Diameter of the Galaxy 100,000 light years
Classification of the Galaxy SBbc
Number of stars in the Galaxy 200 billion
Mass of the Galaxy 1 trillion solar masses
Length of the central bar 25,000 light years
Distance of the Sun from the centre 26,000 light years
Thickness of the Galaxy at the Sun 2,000 light years
Velocity of Sun around the Galaxy 220 km/s
Orbital period of Sun around the Galaxy 225 million years

Below - four galaxies which look like the Milky Way. NGC 3953 (top left) is 55 million light years away and 95,000 light years in diameter. NGC 5970 (top right) is 105 million light years away and 85,000 light years in diameter. NGC 7329 (bottom left) is even further at a distance of 140 million light years but it is larger with a diameter of 140,000 light years. NGC 7723 (bottom right) is 80 million light years away with a diameter of 90,000 light years.

 How many galaxies are in the Universe?
The known universe consists of about 200 to 300 billion galaxies.
Visit this great site "We Are Not Alone" for more information about stars and galaxies.

How the Milky Way Worksclick here, here & here.
The Stars of the Milky Way
Galactic Habitable Zone

What is a light year?
*One light year is about 5,878,499,000,000 miles.

New Tourist's Guide to the Milky Way
The picture of our galaxy is constantly changing as technology improves.

Travel 10 million light years.....In 1 minutes. (Video)
Travel through your universe from outside the milky way down into the atoms which make up your world.