Tag Archives: habitable zone

Kepler Space Telescope Discovers More Potentially Habitable Planets

Yesterday researchers from the NASA’s Kepler Space Telescope announced the discovery of 833 more candidate planets, 104 of which have the potential to harbor life. Included in that 104 in their respective Goldilocks Zones are 10 that are roughly the same size as Earth. As of this announcement, the total number of exoplanets discovered by Kepler since its launch in 2009 is now at 3,538. Its mission is to explore exoplanets and discover which ones are similar in size to Earth and are capable of supporting life. The announcement is coming from Kepler Science Conference, which is hosting over 400 scientists representing 30 countries.


According to William Borucki, the principal investigator for Kepler’s science mission, these discoveries “[open] a new era of exploration of our galaxy.” The first potentially habitable planet was announced two years ago, and since astronomers now believe there that most stars in the galaxy have at least one planet there is the possibility of many more potentially life-harboring discoveries to come.


This spring, Kepler’s mission was changed when two out of the four wheels used to point the telescope toward its targets broke, and NASA scientists were unable to repair them. Kepler completed its initial mission in 2012, and is currently completing an extended mission. Despite this, there is still a full year’s worth of data that has not been processed yet as Kepler monitored 150,000 stars and recorded data once every half hour for those four operational years. 


One analysis of Kepler’s data suggests that around 20% of sun-like stars have an Earth-like planet. So far, there have not been any reports of any such planet that completely mirrors Earth in terms of habitability and revolution length around a star like ours, but astronomers will continue to search. 

Read more: http://www.iflscience.com/space/kepler-space-telescope-discovers-more-potentially-habitable-planets

Exozodiacal Light Could Hinder Direct Imaging of Earth-Like Exoplanets

Finding life on exoplanets in a star’s habitable zone would, arguably, be the biggest event that has ever happened in human history. Unfortunately, an international team of astronomers using the Very Large Telescope discovered exozodiacal light around nearby stars, which would make imaging Earth-like exoplanets in those systems quite difficult. Steve Ertel from ESO and the University of Grenoble in France was lead author of the paper, which was published in the journal Astronomy & Astrophysics

Zodiacal dust can be generated by comet disintegration, collisions between asteroids or small planetary bodies, and through general space weathering of these bodies. When the tiny dust particles reflect sunlight or become heated enough to glow on their own, it produces a faint white light that can be widely seen throughout the solar system. When this phenomenon occurs in solar systems outside of our own, it’s called exozodiacal dust. 

Ertel’s team studied the exozodiacal dust near the habitable zones of 92 nearby stars, including 14 known to have exoplanets. Observations were made in near-infrared wavelengths using the Very Large Telescope’s Interferometer (VLTI). In order to produce a contrast high enough to view the dust, the VLT was given additional light from the four 1.8 meter Auxiliary Telescopes, allowing it to be ten times more powerful than any other similar instrument in the world. 

“If we want to study the evolution of Earth-like planets close to the habitable zone, we need to observe the zodiacal dust in this region around other stars,” Ertel said in a press release. “Detecting and characterizing this kind of dust around other stars is a way to study the architecture and evolution of planetary systems.”

Radiation from the star tends to push the tiny particles of zodiacal dust away, and a disc is formed past the habitable zone. It was assumed that the amount of dust in the clouds would decrease as the star and its system grew older, as there would be fewer asteroids to collide and create the dust. Interestingly, the stars with the brightest exozodiacal light came from older stars.

This blinding exozodiacal light could be problematic for future studies of each star’s potential planetary system. As if the glare from the star’s light wasn’t bad enough, the dust exacerbates that glare, becoming 1000 times brighter than zodiacal light in our solar system. The 14 stars known to have exoplanets all have extremely bright exozodiacal dust near the habitable zone, which will make it very difficult to directly image those planets. Further studies of the dust are needed to better understand its properties. This is necessary to find a way to circumvent it in order to image potential Earth-like planets in the habitable zone.

“The high detection rate found at this bright level suggests that there must be a significant number of systems containing fainter dust, undetectable in our survey, but still much brighter than the Solar System’s zodiacal dust,” adds co-author Olivier Absil from the University of Liège in Belgium. “The presence of such dust in so many systems could therefore become an obstacle for future observations, which aim to make direct images of Earth-like exoplanets.”

Read more: http://www.iflscience.com/space/exozodiacal-light-could-hinder-direct-imaging-earth-exoplanets

Ranking Exoplanets By Their Ability To Support Life

To date, 1,780 planets have been confirmed to exist beyond our solar system. But how many of these hold the potential to support life? National Geographic have compiled the planets discovered so far into a graph, organizing them by mass and temperature, which are two important limiting factors for the potential to support life. The temperature has to be within a range that can maintain any water present in a liquid state, and the mass needs to be within a range that supports a suitable atmosphere.

Of those 1,780 planets, 16 may have the right conditions to support life. Considering how incredibly vast the universe is it’s certainly likely that many more planets will be discovered over time, but this is a pretty encouraging starting figure. The newly discovered Kepler-186f, the first confirmed Earth-size planet orbiting a star in the habitable zone, was included in the list. 

Check out the image below to see the graphic. An interactive version is available on the National Geographic webpage

Read more: http://www.iflscience.com/space/ranking-exoplanets-their-ability-support-life