Red Dwarf Stars Host Billions of Habitable Planets?

Written by The Night Sky Guy on July 5, 2013 – 6:00 am -

planet_orbiting_red_dwarf_large
Red Dwarf stars may be the best place to look for Earth-like planets., according to a new study.

The most common, humble star in the universe could be a mecca when it comes to astronomers hunting for planets hospitable to life. That’s because a new study is suggesting that red dwarfs – stars that are smaller, dimmer and cooler than our Sun – may have twice as many planets that are in the habitable zone than ever thought. In fact the number of these worlds- ones that have just the right temperature to support liquid water – may number as much as 60 billion. And that’s just in our own Milky Way galaxy.

Read more about this amazing new finding and what impact it will have on exoplanet research in my new article for National Geographic News.


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Video: Weekly Space News Interview

Written by The Night Sky Guy on November 18, 2012 – 3:18 pm -

Check out some of the cool space news coming out this week I highlight on my weekly CTV News channel interview.


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Earth-sized Exoplanets Detected!

Written by The Night Sky Guy on December 20, 2011 – 5:16 pm -

Newly discovered Earth-sized exoplanets. Credit: NASA

Size comparison of newly discovered exoplanets that now hold record as smallest yet detected. Credit: NASA

We have just gotten a whole lot closer to finding that Holy Grail in astronomy- that elusive sister Earth. NASA announced that its Kepler spacecraft has spied the telltale light signatures of two of the smallest planets ever found – Earth sized rocky planets around a sun-like star 950 light years from us in the summertime constellation Lyra.

NASA says that “Kepler-20e is slightly smaller than Venus, measuring 0.87 times the radius of Earth while Kepler-20f is slightly larger than Earth, measuring 1.03 times its radius.” Both planets call the five-planet system  Kepler-20 home. But before we begin dreaming of vacations on these worlds, astronomers believe both have scorching surface temps measuring probably well over 600 degrees Celsius, orbiting their parent star way too close. So this means that neither planet is within the Goldilocks or habitable zone – and probably means it’s not ideal place for looking for any life there.

But this discovery is VERY exciting because it does signal the beginning of a whole new era in exoplanet hunting because now it has been proved that we have the technology and methods needed to find Earth-like planets. And i think the best is yet to come from Kepler. We might just see Earth’s twin being found in 2012.

“In the cosmic game of hide and seek, finding planets with just the right size and just the right temperature seems only a matter of time,” said Natalie Batalha, Kepler deputy science team lead and professor of astronomy and physics at San Jose State University. “We are on the edge of our seats knowing that Kepler’s most anticipated discoveries are still to come.”

Here is a great little NASA video summary of today’s announcement…

-with quotes from NASA/JPL news release


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Possible Earth-sized Exoplanets Found

Written by The Night Sky Guy on February 2, 2011 – 2:51 pm -

NASA’s Kepler mission has discovered its first Earth-size planet candidates and its first candidates in the habitable zone, a region where liquid water could exist on a planet’s surface. Five of the potential planets are near Earth-size and orbit in the habitable zone of smaller, cooler stars than our Sun.

Candidates require follow-up observations to verify they are actual planets. Kepler also found six confirmed planets orbiting a Sun-like star, Kepler-11. This is the largest group of transiting planets orbiting a single star yet discovered outside our solar system.

“In one generation we have gone from extraterrestrial planets being a mainstay of science fiction, to the present, where Kepler has helped turn science fiction into today’s reality,” said NASA Administrator Charles Bolden. “These discoveries underscore the importance of NASA’s science missions, which consistently increase understanding of our place in the cosmos.”

Kepler-11 is a sun-like star around which six planets orbit. Image credit: NASA/Tim Pyle

The discoveries are part of several hundred new planet candidates identified in new Kepler mission science data, released on Tuesday, Feb. 1. The findings increase the number of planet candidates identified by Kepler to-date to 1,235. Of these, 68 are approximately Earth-size; 288 are super-Earth-size; 662 are Neptune-size; 165 are the size of Jupiter and 19 are larger than Jupiter.  Of the 54 new planet candidates found in the habitable zone, five are near Earth-sized. The remaining 49 habitable zone candidates range from super-Earth size — up to twice the size of Earth — to larger than Jupiter.

The findings are based on the results of observations conducted May 12 to Sept. 17, 2009, of more than 156,000 stars in Kepler’s field of view, which covers approximately 1/400 of the sky.

“The fact that we’ve found so many planet candidates in such a tiny fraction of the sky suggests there are countless planets orbiting Sun-like stars in our galaxy,” said William Borucki of NASA’s Ames Research Center in Moffett Field, Calif., the mission’s science principal investigator. “We went from zero to 68 Earth-sized planet candidates and zero to 54 candidates in the habitable zone, some of which could have moons with liquid water.”

Among the stars with planetary candidates, 170 show evidence of multiple planetary candidates. Kepler-11, located approximately 2,000 light years from Earth, is the most tightly packed planetary system yet discovered. All six of its confirmed planets have orbits smaller than Venus, and five of the six have orbits smaller than Mercury’s.

The only other star with more than one confirmed transiting planet is Kepler-9, which has three. The Kepler-11 findings will be published in the Feb. 3 issue of the journal Nature.

his artist’s conception shows the Kepler-11 planetary system and our solar system from a tilted perspective to demonstrate that the orbits of each lie on similar planes. Image credit: NASA/Tim Pyle

“Kepler-11 is a remarkable system whose architecture and dynamics provide clues about its formation,” said Jack Lissauer, a planetary scientist and Kepler science team member at Ames. “These six planets are mixtures of rock and gases, possibly including water. The rocky material accounts for most of the planets’ mass, while the gas takes up most of their volume. By measuring the sizes and masses of the five inner planets, we determined they are among the lowest mass confirmed planets beyond our solar system.”

All of the planets orbiting Kepler-11 are larger than Earth, with the largest ones being comparable in size to Uranus and Neptune. The innermost planet, Kepler-11b, is ten times closer to its star than Earth is to the Sun. Moving outward, the other planets are Kepler-11c, Kepler-11d, Kepler-11e, Kepler-11f, and the outermost planet, Kepler-11g, which is half as far from its star as Earth is from the Sun.

The planets Kepler-11d, Kepler-11e and Kepler-11f have a significant amount of light gas, which indicates that they formed within a few million years of the system’s formation.

“The historic milestones Kepler makes with each new discovery will determine the course of every exoplanet mission to follow,” said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington.

Kepler, a space telescope, looks for planet signatures by measuring tiny decreases in the brightness of stars caused by planets crossing in front of them. This is known as a transit.

Since transits of planets in the habitable zone of Sun-like stars occur about once a year and require three transits for verification, it is expected to take three years to locate and verify Earth-size planets orbiting Sun-like stars.

The Kepler science team uses ground-based telescopes and the Spitzer Space Telescope to review observations on planetary candidates and other objects of interest the spacecraft finds.

The star field that Kepler observes in the constellations Cygnus and Lyra can only be seen from ground-based observatories in spring through early fall. The data from these other observations help determine which candidates can be validated as planets.

More information about the Kepler mission:

http://www.nasa.gov/kepler


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Space News This Week

Written by The Night Sky Guy on January 22, 2011 – 12:19 pm -

This week in space news we talk about the hottest and smallest exoplanet discoveries to date and a unprecedented storm of comets has been seen to bombard the Sun. Check out my national news interview below…


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Carbon Exoplanet Interview

Written by The Night Sky Guy on December 12, 2010 – 2:41 pm -

This week astronomers announced finding a planet rich in carbon orbiting a star 1200 light years away. WASP12b is a gas giant 1.4 times the mass of Jupiter with atmospheric temperatures of 2300 degrees Celcius. Life is unlikely but it is the most carbon rich planet ever seen. This astronomers say have implications for finding life in the universe since carbon is a vital building block of life. It also shows that planet forming chemistry can be very different from how Earth and all the planets in our solar system formed. There is so much carbon on this planet that its interior may even include diamonds. Herei s an TV news interview I did this weekend on this discovery…


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Potentially Habitable Exoplanet Found

Written by The Night Sky Guy on September 29, 2010 – 6:18 pm -

his artists conception shows the inner four planets of the Gliese 581 system and their host star. Image Credit: Lynette Cook.

This artist's conception shows the inner four planets of the Gliese 581 system and their host star. Image Credit: Lynette Cook.

A team of planet hunters has announced the discovery of a planet with three times the mass of Earth orbiting a nearby star at a distance that places it squarely in the middle of the star’s “habitable zone.”

This discovery was the result of more than a decade of observations using the W. M. Keck Observatory in Hawaii, one of the world’s largest optical telescopes. The research placed the planet in an area where liquid water could exist on the planet’s surface. If confirmed, this would be the most Earth-like exoplanet yet discovered and the first strong case for a potentially habitable one.

To astronomers, a “potentially habitable” planet is one that could sustain life, not necessarily one where humans would thrive. Habitability depends on many factors, but having liquid water and an atmosphere are among the most important. The new findings are based on 11 years of observations of the nearby red dwarf star Gliese 581 using the HIRES spectrometer on the Keck I Telescope. The spectrometer allows precise measurements of a star’s radial velocity (its motion along the line of sight from Earth), which can reveal the presence of planets. The gravitational tug of an orbiting planet causes periodic changes in the radial velocity of the host star. Multiple planets induce complex wobbles in the star’s motion, and astronomers use sophisticated analyses to detect planetsand determine their orbits and masses.

“Keck’s long-term observations of the wobble of nearby stars enabled the detection of this multi-planetary system,” said Mario R. Perez, Keck program scientist at NASA Headquarters in Washington. “Keck is once again proving itself an amazing tool for scientific research.” Steven Vogt, professor of astronomy and astrophysics at UC Santa Cruz, and Paul Butler of the Carnegie Institution lead the Lick-Carnegie Exoplanet Survey.

“Our findings offer a very compelling case for a potentially habitable planet,” said Vogt. “The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common.”

The paper reports the discovery of two new planets around Gliese 581. This brings the total number of known planets around this star to six, the most yet discovered in a planetary system outside of our own. Like our solar system, the planets around Gliese 581 have nearly-circular orbits.

The planetary orbits of the Gliese 581 system compared to those of our own solar system. Image Credit: NSF

The planetary orbits of the Gliese 581 system compared to those of our own solar system. click image to enlarge; Image Credit: NSF

The new planet designated Gliese 581g has a mass three to four times that of Earth and orbits its star in just under 37 days. Its mass indicates that it is probably a rocky planet with a definite surface and enough gravity to hold on to an atmosphere. Gliese 581, located 20 light years away from Earth in the constellation Libra, has two previously detected planets that lie at the edges of the habitable zone, one on the hot side (planet c) and one on the cold side (planet d). While some astronomers still think planet d may be habitable if it has a thick atmosphere with a strong greenhouse effect to warm it up, others are skeptical. The newly-discovered planet g, however, lies right in the middle of the habitable zone.

The planet is tidally locked to the star, meaning that one side is always facing the star and basking in perpetual daylight, while the side facing away from the star is in perpetual darkness. One effect of this is to stabilize the planet’s surface climates, according to Vogt. The most habitable zone on the planet’s surface would be the line between shadow and light (known as the “terminator”).

- adapted from a NASA news announcement


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Most Earth-like Planet Yet Found

Written by The Night Sky Guy on September 17, 2009 – 10:06 am -

Using a planet-hunting space telescope called CoRoT, astronomers have discoverd the most Earth-like world – one that has a rocky surface. Every 20.4 hours, the planet eclipses a small fraction of the light of the star for a little over one hour by one part in 3000.

This planet, designated CoRoT-7b, is only 2.5 million kilometers away from its host star, or 23 times closer than Mercury is to the Sun. It has a radius that is about 80% greater than the Earth’s.

Click image to enlarge

Click image to enlarge

With a mass much closer to that of Earth than, for example, ice giant Neptune’s 17 Earth masses, CoRoT-7b belongs to the category of “super-Earth” exoplanets. About a dozen of these bodies have been detected, though in the case of CoRoT-7b, this is the first time that the density has been measured for such a small exoplanet. The calculated density is close to Earth’s, suggesting that the planet’s composition is similarly rocky. CoRoT-7b earns another distinction as the closest known exoplanet to its host star, which also makes it the fastest — it orbits its star at a speed of more than 750,000 kilometers per hour, more than seven times faster than the Earth’s motion around the Sun. “In fact,CoRoT-7b is so close that the place may well look like Dante’s Inferno, with a probable temperature on its ‘day-face’ above 2000 degrees and minus 200 degrees on its night face. Theoretical models suggest that the planet may have lava or boiling oceans on its surface. With such extreme conditions this planet is definitively not a place for life to develop,” says one of the co-discoverers.

Doorstep Astronomy: The parent star, now known as CoRoT-7, is and 11th magnitude star located in the constellation of Monoceros (the Unicorn) (see starchart above) at a distance of about 500 light-years. Slightly smaller and cooler than our Sun, CoRoT-7 is also thought to be younger, with an age of about 1.5 billion years. It is faintly visible through a backyard telescope, but you can easily find its location in the eastern early morning sky with the naked eye located between the  bright star-like Venus and the brilliant constellation Orion.


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Earth-Hunting Space Scope Ready for Action

Written by The Night Sky Guy on August 6, 2009 – 5:02 pm -

NASA’s new Kepler space telescope has detected the atmosphere of a known giant gas planet, demonstrating the telescope’s extraordinary scientific capabilities….these new data indicate the mission is indeed capable of finding Earth-like planets, if they exist….”When the light curves from tens of thousands of stars were shown to the Kepler science team, everyone was awed; no one had ever seen such exquisitely detailed measurements of the light variations of so many different types of stars,” said William Borucki, the principal science investigator….

The observations were collected from a planet called HAT-P-7, known to transit a star located about 1,000 light years from Earth. The planet orbits the star in just 2.2 days and is 26 times closer than Earth is to the sun. …It is so close to its star, the planet is as hot as the glowing red heating element on a stove.

…”This early result shows the Kepler detection system is performing right on the mark,” said David Koch, deputy principal investigator of NASA’s Ames Research Center at Moffett Field, Calif. “It bodes well for Kepler’s prospects to be able to detect Earth-size planets.”

- adapted from material taken from a NASA news announcement.

click image to enlarge

click image to enlarge

Backyard Astro Hunt: Try your hand at hunting down where in the sky this alien world is located. No chance in seeing the planet but its neat to be able to point out where it is in the sky. The parent star HAT-P 7 goes by another more widely used but even less romantic designation TYC 3547-1402-1. The star’s coordinates are RA: 19h 28m 59s ; Dec: +47 58m 10s which lies in the constellation Cygnus, the swan, otherwise known as the northern Cross. Those of you with planetarium softwares might be able to find it using this other name and position. Cygnus dominates the southern overhead skies at night during the entire summer. HAT-P 7 is located just underneath the right arm of the cross.

click to enlarge

While we can only imagine what this 1000 light year distant world looks like, I think its kind of cool to find the general area in the night sky with just the naked-eye where these kind of discoveries are being made.

The parent star is classified as a yellow dwarf quite similar to our own Sun – hence all the interest in observing it for planets. It has a magnitude 10.4 which makes it possible to spot the general area where it is located if not the diminutive star itself in small telescopes.


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