Recently, NASA gave an extremely encouraging press release concerning, quoted below, concerning the discovery of planets within the “habitable zone” around stars in our universe.
By refining the orbit of the planet Gliese 581 d, first discovered in 2007, a team of astronomers has shown that it lies well within the habitable zone, where liquid water oceans could exist. This diagram shows the distances of the planets in the Solar System (upper row) and in the Gliese 581 system (lower row), from their respective stars (left). The habitable zone is indicated as the blue area, showing that Gliese 581 d is located inside the habitable zone around its low-mass red star. Based on a diagram by Franck Selsis, Univ. of Bordeaux.
The habitable zone, sometimes called the “circumstellar habitable zone,” is the region around stars within which planetary-mass objects with sufficient atmospheric pressure could support liquid water at the surface. Or more simply put, it the region of space around any given star where planets might support extraterrestial life, or any other form of life as we currently understand living organisms to operate.
Personally, I think the video below entitled “NASA’s Kepler Discovers Its Smallest ‘Habitable Zone’ Planets to Date,” the photos, and the press release will explain it all considerably better then I can, so I’ll get out of the way and let you all sort it out for yourselves.
Size of Habitable Zone Planets
The only other thing I will mention is that according to the Telegraph’s science article “There Could Be 100 Billion Earth-like Planets Say Astronomers,” by Richard Gray, Science Correspondent:
Scientists at the University of Auckland… claim that by combining data from a Nasa space telescope that is currently searching the heavens for other planets with a ground based technique called gravitational microlensing, it will be possible to identify smaller Earth-like planets in the right orbit. They estimate there could be as many as 100 billion of these planets in the Milky Way, our own galaxy. With roughly 300 billion stars in our galaxy, this figure may not be as unlikely as it first seems…
Location Habitable Zone Planets
The NASA Press Release concerning habitable zone planets:
April 18, 2013
J.D. Harrington
Headquarters, Washington
202-358-5241
j.d.harrington@nasa.govMichele Johnson
Ames Research Center, Moffett Field, Calif.
650-604-4789
michele.johnson@nasa.govRELEASE: 13-112
NASA’S KEPLER DISCOVERS ITS SMALLEST ‘HABITABLE ZONE’ PLANETS TO DATE
WASHINGTON — NASA’s Kepler mission has discovered two new planetary systems that include three super-Earth-size planets in the “habitable zone,” the range of distance from a star where the surface temperature of an orbiting planet might be suitable for liquid water.
The Kepler-62 system has five planets; 62b, 62c, 62d, 62e and 62f. The Kepler-69 system has two planets; 69b and 69c. Kepler-62e, 62f and 69c are the super-Earth-sized planets.
Two of the newly discovered planets orbit a star smaller and cooler than the sun. Kepler-62f is only 40 percent larger than Earth, making it the exoplanet closest to the size of our planet known in the habitable zone of another star. Kepler-62f is likely to have a rocky composition. Kepler-62e, orbits on the inner edge of the habitable zone and is roughly 60 percent larger than Earth.
The third planet, Kepler-69c, is 70 percent larger than the size of Earth, and orbits in the habitable zone of a star similar to our sun. Astronomers are uncertain about the composition of Kepler-69c, but its orbit of 242 days around a sun-like star resembles that of our neighboring planet Venus.
Scientists do not know whether life could exist on the newfound planets, but their discovery signals we are another step closer to finding a world similar to Earth around a star like our sun.
“The Kepler spacecraft has certainly turned out to be a rock star of science,” said John Grunsfeld, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. “The discovery of these rocky planets in the habitable zone brings us a bit closer to finding a place like home. It is only a matter of time before we know if the galaxy is home to a multitude of planets like Earth, or if we are a rarity.”
The Kepler space telescope, which simultaneously and continuously measures the brightness of more than 150,000 stars, is NASA’s first mission capable of detecting Earth-size planets around stars like our sun.
Orbiting its star every 122 days, Kepler-62e was the first of these habitable zone planets identified. Kepler-62f, with an orbital period of 267 days, was later found by Eric Agol, associate professor of astronomy at the University of Washington and co-author of a paper on the discoveries published in the journal Science.
The size of Kepler-62f is now measured, but its mass and composition are not. However, based on previous studies of rocky exoplanets similar in size, scientists are able to estimate its mass by association.
“The detection and confirmation of planets is an enormously collaborative effort of talent and resources, and requires expertise from across the scientific community to produce these tremendous results,” said William Borucki, Kepler science principal investigator at NASA’s Ames Research Center at Moffett Field, Calif., and lead author of the Kepler-62 system paper in Science. “Kepler has brought a resurgence of astronomical discoveries and we are making excellent progress toward determining if planets like ours are the exception or the rule.”
The two habitable zone worlds orbiting Kepler-62 have three companions in orbits closer to their star, two larger than the size of Earth and one about the size of Mars. Kepler-62b, Kepler-62c and Kepler-62d, orbit every five, 12, and 18 days, respectively, making them very hot and inhospitable for life as we know it.
The five planets of the Kepler-62 system orbit a star classified as a K2 dwarf, measuring just two-thirds the size of the sun and only one-fifth as bright. At seven billion years old, the star is somewhat older than the sun. It is about 1,200 light-years from Earth in the constellation Lyra.
A companion to Kepler 69c, known as Kepler 69b, is more than twice the size of Earth and whizzes around its star every 13 days. The Kepler-69 planets’ host star belongs to the same class as our sun, called G-type. It is 93 percent the size of the sun and 80 percent as luminous and is located approximately 2,700 light-years from Earth in the constellation Cygnus.
“We only know of one star that hosts a planet with life, the sun. Finding a planet in the habitable zone around a star like our sun is a significant milestone toward finding truly Earth-like planets,” said Thomas Barclay, Kepler scientist at the Bay Area Environmental Research Institute in Sonoma, Calif., and lead author of the Kepler-69 system discovery published in the Astrophysical Journal.
When a planet candidate transits, or passes in front of the star from the spacecraft’s vantage point, a percentage of light from the star is blocked. The resulting dip in the brightness of the starlight reveals the transiting planet’s size relative to its star. Using the transit method, Kepler has detected 2,740 candidates. Using various analysis techniques, ground telescopes and other space assets, 122 planets have been confirmed.
Early in the mission, the Kepler telescope primarily found large, gaseous giants in very close orbits of their stars. Known as “hot Jupiters,” these are easier to detect due to their size and very short orbital periods. Earth would take three years to accomplish the three transits required to be accepted as a planet candidate. As Kepler continues to observe, transit signals of habitable zone planets the size of Earth orbiting stars like the sun will begin to emerge.
Ames is responsible for Kepler’s ground system development, mission operations, and science data analysis. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development.
Ball Aerospace Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.
The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA’s 10th Discovery Mission and was funded by the agency’s Science Mission Directorate.
For more information about the Kepler mission, visit:
http://www.nasa.gov/kepler
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“NASA’s Kepler Discovers Its Smallest ‘Habitable Zone’ Planets to Date”
