Astro Blog

https://www.mercury-messenger.org/history-culture/galileo-telescope By Shanil Virani, Astronomical Society of the Pacific - Mercury online Excerpt: Between January 7 and January 13, 1610, a series of observations was made that would forever change how we would view the cosmos. The observer detailed in this log book a discovery made using a relatively new invention at that time. The observer had discovered four small, point sources of light very close to the (giant) planet Jupiter. On January 10, one of them disappeared for a short period. The observer attributed the disappearance of the object as being hidden behind Jupiter. Given his extensive observations, he was now forced to conclude that these four points of light were orbiting Jupiter and not Earth. The observer, Galileo Galilei, and his two small pieces of glass would usher in a scientific revolution that reverberates to this day. Until this discovery, and for some 1,500 years prior to Galileo, our ancestors accepted the m...

https://exoplanets.nasa.gov/news/1704/discovery-alert-a-flood-of-new-planets-plus-hint-of-an-exomoon/ By Pat Brennan, NASA's Exoplanet Exploration Program.  Excerpt: Data from NASA’s now-retired Kepler Space Telescope reveals an eclectic assortment of new planets and planetary systems that promises to deepen understanding of how exoplanets form. Some of the newly-discovered planets might make tempting targets for the James Webb Space Telescope, now being fine-tuned for its first observations this summer. The Webb telescope is expected to search for signs of atmospheres around some exoplanets, and potentially determine some of the gases and molecules present. This raft of new planets also helped push NASA’s tally of confirmed exoplanets past the 5,000 mark in March 2022. ...Combing through Kepler data also revealed another potentially significant find: a possible exomoon. ...The new possible exomoon, Kepler-1708 b-i, would be very large for a moon, about 2.6 times as big around as E...

https://skyandtelescope.org/astronomy-news/kepler-retrospective-earth-like-planets-common/ Source:  Sky and Telescope Magazine.  Excerpt: ...NASA’s Kepler telescope was retired a few years ago, but ongoing analyses of its data, both by professional astronomers and  citizen scientists , are still producing new results. ...Kepler has found more than 2,600 exoplanets (and counting). Now, an international collaboration led by Steve Bryson, a researcher at NASA Ames, has announced a refined estimate. The team, including NASA scientists, SETI researchers, academics, former-Keplerites, and other planet hunters, performed a statistical analysis that combined Kepler’s planet catalog and stellar data from the European Space Agency’s Gaia observatory. They found that about half of the Sun-like stars in our galaxy could have a rocky planet in their habitable zones. ... The study , soon to be published in The Astronomical Journal, predicts that there are at least 300 million habitab...

https://www.bbc.com/news/science-environment-49648746 Source:   By Pallab Ghosh, BBC News. Excerpt: Astronomers have for the first time discovered water in the atmosphere of a planet orbiting within the habitable zone of a distant star. The finding makes the world - which is called K2-18b - a plausible candidate in the search for alien life. ...Details were published in the scientific journal Nature Astronomy [ https://www.nature.com/articles/s41550-019-0878-9 ]. ...K2-18b is 111 light-years - about 650 million million miles - from Earth, too far to send a probe. ...The team behind the discovery looked through the planets discovered by the Hubble Space Telescope between 2016 and 2017. The researchers determined some of the chemicals in their atmosphere by studying the changes to the starlight as the planets orbited their suns. The light filtered through the planets' atmospheres was subtly altered by the composition of the atmosphere.Only K2-18b revealed  the molecular sign...

https://www.sciencenews.org/article/first-planet-kepler-finally-confirmed-10-years-later Source:   By Lisa Grossman, Science News. Excerpt: A decade after being found, the first exoplanet candidate spotted by the Kepler space telescope has been confirmed as a real world. The planet orbits a star initially dubbed KOI 4, for Kepler Object of Interest 4 (KOIs 1 through 3 were known before Kepler launched in March 2009). ...The Kepler team originally thought the star was about 1.1 times the width of the sun, which would make the planet about the size of Neptune. But then astronomers saw a second dip in starlight as the world passed behind the star, called a secondary eclipse. That second dip shouldn’t be visible for such a small planet, so the exoplanet candidate was dismissed as a false alarm. ...KOI 4 is actually about three times the width of the sun, meaning its planet would be about three times as large as first estimated — or a bit larger than Jupiter, the team found. That’s ...

https://www.nasa.gov/press-release/nasa-retires-kepler-space-telescope-passes-planet-hunting-torch Source:   NASA RELEASE 18-092. Excerpt: After nine years in deep space collecting data that indicate our sky to be filled with billions of hidden planets – more planets even than stars – NASA’s Kepler space telescope has run out of fuel needed for further science operations. NASA has decided to retire the spacecraft within its current, safe orbit, away from Earth. Kepler leaves a legacy of more than 2,600 planet discoveries from outside our solar system, many of which could be promising places for life. "As NASA's first planet-hunting mission, Kepler has wildly exceeded all our expectations and paved the way for our exploration and search for life in the solar system and beyond," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate in Washington. ...The most recent analysis of Kepler’s discoveries concludes that 20 to 50 percent of the...

https://www.sciencemag.org/news/2018/10/first-moon-outside-solar-system-could-be-big-neptune Source:   By Joshua Sokol, Science Magazine. Excerpt: With help from the Hubble Space Telescope, astronomers say they have found compelling evidence for the first known moon outside the solar system. ...this first reported “exomoon” is also strange: a Neptune-size megamoon, some 8000 light-years away, that looms over a giant planet, twice as large in the sky as Earth’s moon. ...Most theoretical models of planet formation struggle to produce such a hefty satellite. However, searches are biased toward the largest moons that might be out there, because bigger things are easier to detect. ...The first hints for the exomoon came from archival data from the Kepler probe, a NASA planet-hunting spacecraft, which looks for dips in brightness caused by unseen planets transiting in front of their suns. Alex Teachey and David Kipping, both of Columbia University, found that three dips, attributed t...

https://eos.org/features/the-kepler-revolution Source:   By Kimberly M. S. Cartier, Eos/AGU. Excerpt: The Kepler Space Telescope will soon run out of fuel and end its mission. Here are nine fundamental discoveries about planets aided by Kepler in the 9 years since its launch. ...Kepler Space Telescope, a small spacecraft that opened a large window to the many thousands of exoplanets strewn throughout the Milky Way ...was exhibiting the first signs of low fuel and ... would be functional for only a few more months. Its fuel tank hit critically low levels on 2 July, and mission scientists put Kepler into a no-fuel hibernation mode until its latest round of data can be downloaded on 2 August. ...1. Planets Are Everywhere, Equally. ...Through its unblinking gaze, Kepler discovered 4,571 planetary signatures, 2,327 of which have been confirmed as actual exoplanets. . ..2. The Solar System May Not Be Unique. ...With the help of an artificial intelligence algorithm, Kepler discover...

https://www.nasa.gov/press-release/artificial-intelligence-nasa-data-used-to-discover-eighth-planet-circling-distant-star  [includes video] Source:   NASA RELEASE 17-098 Excerpt: Our solar system now is tied for most number of planets around a single star, with the recent discovery of an eighth planet circling Kepler-90, a Sun-like star 2,545 light-years from Earth. The planet was discovered in data from NASA’s Kepler Space Telescope. The newly-discovered Kepler-90i – a sizzling hot, rocky planet that orbits its star once every 14.4 days – was found using machine learning from Google. Machine learning is an approach to artificial intelligence in which computers “learn.” In this case, computers learned to identify planets by finding in Kepler data instances where the telescope recorded signals from planets beyond our solar system, known as exoplanets. “Just as we expected, there are exciting discoveries lurking in our archived Kepler data, waiting for the right tool or tech...

Source:   By JoAnna Wendel, Earth & Space Science News, EoS, AGU Excerpt: NASA introduced 219 exoplanet candidates to the world on Monday. Ten of these are roughly Earth sized and orbit their stars in the so-called habitable zone, a distance at which temperatures could be ripe for liquid water. The candidate exoplanets appear in the eighth and newest catalog from the agency’s exoplanet-hunting Kepler space telescope and the final catalog from Kepler’s observations of the Cygnus constellation. The new catalog includes 4034 exoplanet candidates overall. Past “Kepler catalogs have shown us that small exoplanets are common,” Susan Thompson, lead author on the catalog study and a research scientist at the SETI Institute in Mountain View, Calif., told Eos. “With this [latest] catalog, we can show whether this is also true for exoplanets that are in orbital periods similar to those of the Earth.” Accompanying research also reveals that the majority of known exoplanets fall into t...

Source:   By Dennis Overbye, The New York Times 2017-06-19. . . For GSS A Changing Cosmos chapter 8. Excerpt: ...astronomers released a list on Monday of 4,034 objects they are 90 percent sure are planets orbiting other stars. The new list is the final and most reliable result of a four-year cosmic census of a tiny region of the Milky Way by NASA’s Kepler spacecraft. ... The catalog — the eighth in the endeavor — was released at a meeting of exoplanet astronomers here at the Ames Research Center that represents a last hurrah for the survey mission, which will end on Sept. 30. The space telescope itself is doing fine, and it has embarked on a new program of short-term searches called K2. Among other things, Dr. Batalha said, for the first time there is at least one planet, known as KOI 7711 (for Kepler Object of Interest), that almost matches the Earth, at only 30 percent wider and with an orbit of almost exactly one year. In all, there are 219 new planet candidates in the catal...

Source:   NASA Excerpt: 550 of the 1,284 new Kepler planets are small possibly rocky; 9 of those reside in habitable zone.... http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=415

Source:  Jonathan Corum, New York Times                  This is an interactive showing more than 100 Kepler planet discoveries with a known size and orbit, including five planets orbiting Kepler 62, announced on April 18.  http://www.nytimes.com/interactive/science/space/keplers-tally-of-planets.html

Source:  NASA Kepler Mission Excerpt:  ...We're a step closer to knowing if our galaxy is home to a multitude of planets like Earth or if we are a rarity. The three habitable zone super-Earth-size planets are in two systems containing a total of seven newly discovered planets...Star Kepler-62 is not Sun-like: just 2/3 the size of the Sun, cooler, older, and only 1/5 as bright. Planet Kepler-62f, 40% larger than Earth, the smallest known habitable zone exoplanet, orbits every 267 days. Planet Kepler-62e, about 60% larger than Earth, orbits every 122 days in the the habitable zone's inner edge. http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=243

Source:   Dan Vergano, USA TODAY Excerpt: …some solace comes from the Kepler space telescope team's estimate that just in our Milky Way galaxy alone, some 500 million planets likely orbit inside their star's habitable zone. "We have many candidates in that region," said Kepler principal scientist William Borucki of NASA's Ames Research Center in Moffett Field, Calif., at a briefing unveiling Kepler-22b to his colleagues earlier this month. At his briefing, Borucki showed a chart depicting more than 50 possible habitable zone planets, … www.usatoday.com/tech/science/columnist/vergano/story/2011-12-18/kepler-habitable-planets/52031444/1

Source:   Ron Cowen, Nature Excerpt:  The Kepler spacecraft has hit an unexpected obstacle as it patiently watches the heavens for exoplanets: too many rowdy young stars. The orbiting probe detects small dips in the brightness of a star that occur when a planet crosses its face. But an analysis …has found that the stars themselves flicker more than predicted, with the largest number varying twice as much as the Sun. That makes it harder to detect Earth-sized bodies. …the analysis suggests that Kepler will need more than double its planned mission life of three-and-a-half years to achieve its main goal of determining how common Earth-like planets are in the Milky Way.... "We need an extended mission because the detection of Earth-sized planets hangs in the balance," says Geoff Marcy ... a member of the Kepler team....  www.nature.com/news/2011/110906/full/477142a.html

Source:  Madeleine Amberge, Deutsche Welle Excerpt: Astronomers have made a quantum leap in the search for other life forms in the universe thanks to NASA's new Kepler space telescope, which has identified more than 700 potential exosolar planets. ...Geoff Marcy...is the most successful planet hunter of all time, discovering more than 70 exosolar planets, most of them gas giants like our own Jupiter. "It's true that finding a Jupiter is a little bit ho-hum," he told Deutsche Welle. "Saturns don't get me up in the morning, nor do Neptunes. But with this Kepler telescope, we're getting so close to finding new Earths that the hairs on the back of my neck are standing up." www.dw-world.de/dw/article/0,,5742970,00.html

Source:  NASA/JPL Excerpt: NASA's Kepler Mission has released 43 days of science data on more than 156,000 stars. These stars are being monitored for subtle brightness changes as part of an ongoing search for Earth-like planets outside of our solar system. Astronomers will use the new data to determine if orbiting planets are responsible for brightness variations in several hundred stars. http://www.jpl.nasa.gov/news/news.cfm?release=2010-200