Earth-size Planet Discovered Orbiting Within Habitable Zone of Star

Earth-sized planets could be more common than we first assumed

This artists conception of Kepler-186f is elegant, but still imagination at work
This artist’s conception of Kepler-186f is elegant, but still imagination at work

Space news (astrophysics: exoplanets; Kepler-186f )

NASA astronomers working with the Kepler Space Telescope have discovered the first Earth-sized planet orbiting within the ‘habitable zone’ of its host star. Kepler-186f, as its name implies, is in the Kepler-186 star system, around 500 light-years from Sol in the constellation Cygnus. A discovery that implies planets the size of Earth, residing within their host star’s habitable zone, could be more common than we first thought.

Space scientists believe there’s a good chance Kepler-186f is a rocky planet, similar in many ways to the Earth. The fact it resides within the habitable zone implies liquid water could exist on the surface of this planet and possibly life based on the same principles as on Earth. The M dwarf, or red dwarf, sun it orbits is a common star making up about 70 percent of the suns in our home galaxy and is only half the volume and mass of Sol. This star is also orbited by four other planets, according to the latest information, but this number could change as more data is obtained.

“The discovery of Kepler-186f is a significant step toward finding worlds like our planet Earth,” said Paul Hertz, NASA’s Astrophysics Division director at the agency’s headquarters in Washington. “Future NASA missions, like the Transiting Exoplanet Survey Satellite and the James Webb Space Telescope, will discover the nearest rocky exoplanets and determine their composition and atmospheric conditions, continuing humankind’s quest to find truly Earth-like worlds.”

NASA astronomers have no idea, yet, what Kepler-186f is made of, or even its mass. They’ll now focus more instruments and time to look into some of these facts, and hopefully, soon we’ll know a lot more about this possible twin-Earth.

“We know of just one planet where life exists — Earth. When we search for life outside our solar system we focus on finding planets with characteristics that mimic that of Earth,” said Elisa Quintana, a research scientist at the SETI Institute at NASA’s Ames Research Center in Moffett Field, Calif., and lead author of the paper published today in the journal Science. “Finding a habitable zone planet comparable to Earth in size is a major step forward.”

Earth-size planets are more familiar to scientists than the larger planets discovered lying within the habitable zone of their host stars. It will be easier to understand the data they obtain concerning Kepler-186f, and hopefully, this translates into a better picture of the planet.

M dwarfs are the most numerous stars,” said Quintana. “The first signs of other life in the galaxy may well come from planets orbiting an M dwarf.”

What would a day on Kepler-186f be like? This planet is near the outer boundary of its host star’s habitable zone, which results in it receiving about 30 percent of the energy Earth gets from Sol. Viewed from the surface of the planet at high noon, the host star would only be as bright as Sol an hour before sunset. A day on Kepler-186f isn’t going to be a walk in the park on a sunny day.

“Being in the habitable zone does not mean we know this planet is habitable. The temperature on the planet is strongly dependent on what kind of atmosphere the planet has,” said Thomas Barclay, a research scientist at the Bay Area Environmental Research Institute at Ames, and co-author of the paper. “Kepler-186f can be thought of as an Earth-cousin rather than an Earth-twin. It has many properties that resemble Earth.”

What’s next for the team?

The next step for NASA astronomers is to find Earth-size planets that are a true twin for Earth, which will be a day to remember. Determining the chemical composition of any planets found will be an exciting time for both astronomers and humankind. A planet with a similar chemical composition to Earth would open up eyes and change the prospect of the possibility of alien life in the galaxy and universe.

It would truly be something to experience.

What is the possibility of alien life existing in the universe? Read “The Possibility of Intelligent Lifeforms Existing in the Universe”.

What has Kepler discovered lately? Read “Kepler Mission Introduces 715 New Planets

Read about “The Search for Life Beyond Earth Takes a Turn at Jupiter

Watch this YouTube video on Kepler-186f

This artists conception of depicts multiple-transiting planet systems seen edge-on from the vantage point of the viewer

Kepler Mission Introduces 715 New Planets

This artists conception of depicts multiple-transiting planet systems seen edge-on from the vantage point of the viewer
This artist’s conception of depicts multiple-transiting planet systems seen edge-on from the vantage point of the viewer

Astronomy News –

NASA announced recently the Kepler mission had found another 715 planets orbiting distant stars. Astronomers determined these planets orbit a total of 305 stars, but this total could change after all the facts are in. This points to a lot more multiple planet-star systems, like our own solar system existing in the Milky Way.

NASA announced recently the Kepler mission had found another 715 planets orbiting distant stars. Astronomers determined these planets orbit a total of 305 stars, but this total could change after all the facts are in. This points to a lot more multiple planet-star systems, like our own solar system existing in the Milky Way.

NASA announced recently the Kepler mission had found another 715 planets orbiting distant stars. Astronomers determined these planets orbit a total of 305 stars, but this total could change after all the facts are in. This points to a lot more multiple planet-star systems, like our own solar system existing in the Milky Way.

Kepler-62f looks dark and foreboding in this artists conception of the exo-planet
Kepler-62f looks dark and foreboding in this artist’s conception of the exo-planet

Astronomers believe around 95 percent of these newly discovered planets are smaller than Neptune, which is nearly four times larger than Earth. This means Earth-size planets outside our own solar system are a lot more common than astronomers first thought.

Kepler-62e is depicted in this artists conception
Kepler-62e is depicted in this artist’s conception

“The Kepler team continues to amaze and excite us with their planet hunting results,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “That these new planets and solar systems look somewhat like our own, portends a great future when we have the James Webb Space Telescope in space to characterize the new worlds.”

Work still to be done

Astronomers have had two decades to work out a new way to identify planets among the thousands of star systems they examine using the Kepler Space Telescope and other instruments. The initial process involves laboriously doing a planet-by-planet analysis to determine if a candidate is a planet. Astronomers now use a statistical technique, which they apply to star systems they think have more than one planet.

Jack Lissauer, a planetary scientist at NASA’s Ames Research Center, and a team of scientists analyzed star systems they think have more than one planet. All of these planet candidates were initially found in the first two years of the Kepler Mission – May 2009 to March 2011.

The statistical technique they used is called verification by multiplicity and it partly uses mathematical probability to determine if a candidate is a planet. Astronomers have observed that planets tend to be found together while stars like to roam on their own. If they find a candidate has two or more planet candidates, then it’s probably a star, with orbiting planets. Using these statistical technique astronomers were able to find these 715 new planets.

“Four years ago, Kepler began a string of announcements of first hundreds, then thousands, of planet candidates –but they were only candidate worlds,” said Lissauer. “We’ve now developed a process to verify multiple planet candidates in bulk to deliver planets wholesale, and have used it to unveil a veritable bonanza of new worlds.”

At least four of these new planets astronomers believe are only 2.5 bigger than Earth and orbit their home sun at a distance compatible with the possibility of life. Planets that fall within the habitable zone, or goldilocks zone, of their home star, are planets where water could exist in its various forms. Astronomers believe the temperature and conditions on these four planets could be suitable for biological life forms to exist.

This artists conception is of Kepler-69 and its possible solar system
This artist’s conception is of Kepler-69 and its possible solar system

The home star of one of these new planets called Kepler-296f, astronomers believe is only half the mass and 5 percent of our own Sun. Kepler-296f astronomers believe is at least twice the size of Earth and they’re wondering if it could be a gaseous world, with a thick soupy atmosphere, or possibly a water planet, with a life-sustaining ocean of water.

What’s next?

“From this study, we learn planets in these multi-systems are small and their orbits are flat and circular — resembling pancakes — not your classical view of an atom,” said Jason Rowe, a research scientist at the SETI Institute in Mountain View, Calif., and co-leader of the research. “The more we explore the more we find familiar traces of ourselves amongst the stars that remind us of home.”

With the latest planets discovered, this puts the total number of planets the Kepler mission has found at around 1,700. Around 961 of these candidates, NASA is sure are planets. One day we will venture out into the unknown of space and land on one of these distant planets. Each planet we discover brings us closer to this day.

You can view the Stream feed here www.ustream.tv/channel/NASA-arc

For more information on the Kepler Space Telescope and its mission to discover planets visit: http://www.nasa.gov/kepler

Read this article on the year ahead for the human journey to the beginning of space and time

Read this article on the Chelyabinsk meteorite

Read this article on a supernova NASA thinks could have given birth to a black hole

Sources:

http://www.nasa.gov/ames/kepler/digital-press-kit-kepler-planet-bonanza

NASA Hosts Media Teleconference to Announce Latest Kepler Discoveries

NASA’s Kepler Mission Announces a Planet Bonanza, 715 New Worlds

All images and diagrams provided by NASA.

Searching for Extraterrestrial Moons

NASA astronomers are optimistic that they'll eventually be able to detect transiting exomoons
NASA astronomers are optimistic that they’ll eventually be able to detect transiting exomoons

Question: Is it possible to detect moons orbiting distant exoplanets? How would this be accomplished?

Questions from the kids (2013-12-30) – If we use our own solar system as an example, we would expect exoplanets to have bodies similar to our own Moon orbiting them. Exomoons, as we’ll refer to them, would be small in comparison to their host planets, and this fact is going to make it more difficult to detect them at the extreme distances involved.

NASA scientists believe exomoons could be a good place for life to start and thrive in many solar systems
NASA scientists believe exomoons could be a good place for life to start and thrive in many solar systems

Despite this fact, astronomers believe exomoons should be detectable, using the same techniques and for the same reasons exoplanets are detected. Exomoons have mass, which means they’ll interact gravitationally with their host planet and sun, causing the exoplanet to move in a mathematically predictable manner in response to the force of gravity. The exomoon will constantly pull on the planet gravitationally, which changes the amount of time it takes the planet to pass in front of its host sun. If an exomoon lines up with its home sun from our point of view here on Earth, this would cause a resulting collection of dips in measured sunlight, just before or after the much more significant transits of the host planet in front of its star. Astronomers believe they can use this fact in the future, along with any new techniques they develop, to search for and find distant exomoons orbiting their home planets.

This detection technique is the most practical way astronomers have developed in order to search for and find distant exomoons. This method provides astronomers with a more direct technique to use in the search for exomoons and at present is the best way to do the job. Currently, NASA’s Kepler telescope, which is looking for smaller transiting exoplanets, is probably our best chance of finding a distant exomoon orbiting its home planet. The Kepler telescope really isn’t designed to search for and find distant exomoons, which makes the job a truly daunting task using this telescope. If we use the largest moon in our solar system, Jupiter’s Ganymede, as an example, we would find Ganymede’s diameter is only about 40 percent of Earth’s. This means Ganymede would only block about 0.0014 percent of the Sun’s light during any transit, which is around six times less than the amount blocked by an Earth transit.

The human journey to the beginning of space and time could one day discover an exomoon looking like this
The human journey to the beginning of space and time could one day discover an exomoon looking like this

All of this is based upon the data and information astronomers have concerning our own solar system, which could be too general, or just wrong. It could be Earth-sized moons orbit transiting planets as large as Jupiter or Saturn, which would mean Kepler would just be able to detect them, and make it possible to search for and find distant exomoons orbiting their home planets.

The best bet astronomers have of finding exomoons orbiting their home planets light-years away will probably be the James Webb Space Telescope once it comes online. This will be when the human journey to the beginning of space and time has the best chance of searching for and finding exomoons orbiting their home planets.

Read about NASA’s Messenger spacecraft and its mission to Mercury

Have you heard about the recent meteorite that exploded near the Ural Mountains

Read about the supernova astronomers are studying looking for a black hole they think was created during the explosion