Astro Blog

Source:   Writer's Almanac Excerpt: ...Before he made his discovery, everyone thought that our Milky Way galaxy was the only galaxy in the universe, and that there wasn’t much outside it besides the Magellanic Clouds, which are visible by the naked eye in the Southern Hemisphere, and which were thought to be clouds of gas or dust. ...Hubble first published his discovery in a paper called “Extragalactic Nature of Spiral Nebulae,” which was presented on this date, in his absence, at a joint meeting of the American Astronomical Society and the American Association for the Advancement of Science. ...Hubble had written his doctoral dissertation on “Photographic Investigations of Faint Nebulae.” With older or smaller telescopes, nebulae just looked like clouds of glowing gas, but with the Hooker telescope — the most powerful telescope in the world at that time — Hubble was able to see that there were actually stars within the nebula. One of the stars in the Andromeda Nebula turned ou...

Source:   By National Radio Astronomy Observatory Excerpt: Astronomers now know that our galaxy is teeming with planets, from rocky worlds roughly the size of Earth to gas giants bigger than Jupiter. Nearly every one of these exoplanets has been discovered in orbit around a mature star with a fully evolved planetary system. New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) contain compelling evidence that two newborn planets, each about the size of Saturn, are in orbit around a young star known as HD 163296. These planets, which are not yet fully formed, revealed themselves by the dual imprint they left in both the dust and the gas portions of the star’s protoplanetary disk. [see image https://public.nrao.edu/wp-content/uploads/2016/12/imagespr2016cbnrao16cb25nrao16cb25a_nrao-1170x600.jpg ]... https://public.nrao.edu/news/2016-alma-planets-disk/

Source:   By Kenneth Chang, The New York Times Excerpt: An ice sheet with more water than Lake Superior may slake the thirst of future astronauts living on Mars. Using radar soundings from NASA’s Mars Reconnaissance Orbiter spacecraft, scientists probed what lies in Utopia Planitia, a 2,000-mile-wide basin within an ancient impact crater. For decades, the region looked intriguing because of polygonal cracking and scalloped depressions in the landscape. In places on Earth like the Canadian Arctic, patterns like these arise from ice beneath the surface. The ground cracks as ice underneath expands and contracts with the changing temperatures; the scallops, as if carved by an ice cream scoop, are places where the surface sinks as the ice melts. “We’d say, ‘It looks like there’s ground ice there,’” Cassie Stuurman, a graduate student at the University of Texas at Austin, said about Utopia Planitia. “What we haven’t known is how much is there.”n ...Ms. Stuurman, the lead author of an...

Source:   By Eric Hand, Science Excerpt: Today, scientists published their first results from a drilling expedition into Chicxulub crater, the buried remnants of an asteroid impact off the Yucatán Peninsula in Mexico that killed off the dinosaurs 66 million years ago. Their discovery of shocked, granite rocks from deep in the crust placed “out of order” on top of sedimentary rocks validates the dynamic collapse theory of formation for Chicxulub’s peak ring, the scientists says. Chicxulub is the only well-preserved crater on Earth with a peak ring, but they abound elsewhere in the inner solar system. Last month, scientists using instruments on a NASA lunar mission showed that the peak rings within the Orientale impact basin were likely to have formed in a similar way as at Chicxulub.... http://www.sciencemag.org/news/2016/11/update-drilling-dinosaur-killing-impact-crater-explains-buried-circular-hills

Source:   By Paul Voosen, Science Excerpt: Some 3.8 billion years ago... A 930-kilometer-wide impact basin perched on the moon’s visible edge, [Mare] Orientale resembles a bull’s-eye, with a smooth interior encircled by three rough rings. ...Do any of the rings match the original crater rim left by the striking asteroid or comet? Now, a new subsurface moon map from NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission, published today in Science, suggests that the answer is no. ...GRAIL’s two spacecraft...measured Orientale from a scant altitude of 2 kilometers. At such close range, the spacecraft were exceptionally sensitive to tiny changes in the moon’s gravity caused by buried rocks of different density–giving the GRAIL team a picture of the subsurface, and a better idea of how the impact actually went down. They found that the Orientale strike hollowed out a crater some 320 to 460 kilometers wide—smaller than any of the rings. Within an hour, the crater’s steep wa...

Source:    By   Robert Sanders , UC Berkeley Media relations Excerpt: Tabby’s star has provoked so much excitement over the past year, with speculation that it hosts a highly advanced civilization capable of building orbiting megastructures to capture the star’s energy, that UC Berkeley’s Breakthrough Listen project is devoting hours of time on the Green Bank radio telescope to see if it can detect any signals from intelligent extraterrestrials. ...“The Breakthrough Listen program has the most powerful SETI [Search for Extraterrestrial Intelligence] equipment on the planet, and access to the largest telescopes on the planet,” said Andrew Siemion, director of the Berkeley SETI Research Center and co-director of Breakthrough Listen. “We can look at it with greater sensitivity and for a wider range of signal types than any other experiment in the world. ” ...“Everyone, every SETI program telescope, I mean every astronomer that has any kind of telesco...

Source:   Lee Billings, Scientific American Excerpt: Follow the pioneering spacecraft’s final descent to the bizarre surface of the distant space traveler.... Shortly before 5 A.M. Eastern time on Friday, the European Space Agency’s Rosetta spacecraft [did] gently fire its thrusters for a few minutes and begin a 14-hour descent to Comet 67P, a mountain-size, snowy dust ball drifting through the darkness that reigns more than half a billion kilometers from the sun. Starved of solar power, Rosetta’s mission is coming to an end after more than a decade of operations, concluding with a crash into the comet it has shadowed through deep space for two years.  [Includes links to other articles about Rosetta's successes.] See also Silence, hugs, and applause as Rosetta’s 12-year mission ends with landing on comet , by Daniel Clery, and  New York Times article  Rosetta Mission Ends With Spacecraft’s Dive Into Comet http://www.scientificamerican.com/article/...

Source:   NASA RELEASE 16-096 Excerpt: Astronomers using NASA's Hubble Space Telescope have imaged what may be water vapor plumes erupting off the surface of Jupiter's moon Europa. ...The observation increases the possibility that missions to Europa may be able to sample Europa’s ocean without having to drill through miles of ice. “Europa’s ocean is considered to be one of the most promising places that could potentially harbor life in the solar system,” said Geoff Yoder, acting associate administrator for NASA’s Science Mission Directorate in Washington. “These plumes, if they do indeed exist, may provide another way to sample Europa’s subsurface.” The plumes are estimated to rise about 125 miles (200 kilometers) before, presumably, raining material back down onto Europa's surface. Europa has a huge global ocean containing twice as much water as Earth’s oceans, but it is protected by a layer of extremely cold and hard ice of unknown thickness. ...If confirmed, Europa wo...

Source:  By Shannon Hall, Earth & Space News (EOS; AGU) Excerpt: ...A new hypothesis might reconcile two opposing theories that have tried to explain Mars's mysterious history... suggests that lush periods just long enough to form water-created surface features, such as canyons, punctuated much longer, planet-wide frozen spells. ...In the 1970s, images of Mars taken by the Mariner and Viking spacecraft revealed enormous channels and valley networks—both of which are reminiscent of catastrophic floods and river drainage systems on Earth. The fluvial features were the first sign that 3.8 billion years ago, the planet was once a lush oasis, awash with oceans, lakes, and rivers. ...a 40-year-long debate that has divided planetary astronomers into two camps: those that think Mars must have once contained a thicker and warmer atmosphere—which made the Red Planet hospitable to liquid water and potentially the evolution of life—and those that think Mars was mostly cold save for sho...

Source:   By Jonathan Corum, The New York Times Excerpt: NASA’s mission to grab pieces of an asteroid and bring them back to Earth took off on Thursday night. “You’ll be glad to know we got everything just exactly perfect,” Dante Lauretta, the mission’s principal investigator, said at a news conference after the launch of the Osiris-Rex spacecraft. The craft began its journey on top of an Atlas 5 rocket that lifted off into the summer sky above Cape Canaveral, Fla. Seven years from now, the craft is to return and parachute a capsule with the asteroid bits into a Utah desert, giving scientists a window to some of the material that made up the early solar system, including some of the molecules that gave rise to life on Earth.... http://www.nytimes.com/interactive/2016/09/08/science/space/nasa-osiris-rex-launch.html

Source:   By Jonathan Corum, The New York Times Excerpt: NASA’s mission to grab pieces of an asteroid and bring them back to Earth took off on Thursday night. “You’ll be glad to know we got everything just exactly perfect,” Dante Lauretta, the mission’s principal investigator, said at a news conference after the launch of the Osiris-Rex spacecraft. The craft began its journey on top of an Atlas 5 rocket that lifted off into the summer sky above Cape Canaveral, Fla. Seven years from now, the craft is to return and parachute a capsule with the asteroid bits into a Utah desert, giving scientists a window to some of the material that made up the early solar system, including some of the molecules that gave rise to life on Earth.... http://www.nytimes.com/interactive/2016/09/08/science/space/nasa-osiris-rex-launch.html

Source:   By Nicholas St. Fleur, The New York Times Excerpt: the very first close-up of Jupiter’s big blue north pole. NASA released several images taken by its Juno spacecraft during its initial orbit around the largest planet in our solar system. For NASA’s astronomers, the images reveal a hardly recognizable picture of the gas giant known for its Great Red Spot. “It’s bluer in color up there than other parts of the planet, and there are a lot of storms,” Scott Bolton, the principal investigator for Juno, said in a statement. “It looks like nothing we have seen or imagined before.”... http://www.nytimes.com/2016/09/03/science/juno-nasa-jupiter.html

Source:   European Southern Observatory eso1629 — Science Release Excerpt: Astronomers using ESO telescopes and other facilities have found clear evidence of a planet orbiting the closest star to Earth, [a red dwarf star] Proxima Centauri [just over four light-years from the Solar System]. The long-sought world, designated Proxima b, orbits its cool red parent star every 11 days and has a temperature suitable for liquid water to exist on its surface. This rocky world is a little more massive than the Earth and is the closest exoplanet to us — and it may also be the closest possible abode for life outside the Solar System. A paper describing this milestone finding was published in the journal Nature on 25 August 2016. ...Proxima Centauri ...cool star in the constellation of Centaurus is too faint to be seen with the unaided eye and lies near to the much brighter pair of stars known as Alpha Centauri AB. Although Proxima b orbits much closer to its star than Mercury does to t...

Source:   By JoAnna Wendel   Earth & Space News EoS (AGU) Excerpt: 1. Dwarf Planets Are as Complex as Regular Planets. ...2. Dwarf Planets Reveal Neptune’s Orbital Origins. ...3. Dwarf Planets Give Us a Peek into the Early Solar System. ...4. Dwarf Planet Candidates Helped Scientists “Find” Planet 9. ...5. Ceres (We Hope) Will Help Us Understand Icy Ocean Moons. ...6. Dwarf Planets Are Prolific.... https://eos.org/articles/six-things-dwarf-planets-have-taught-us-about-the-solar-system

Source:   By Shannon Hall, Scientific American Excerpt: Venus is—without a doubt—Earth’s toxic sibling. Although both worlds are similar in size and density, our planetary neighbor has temperatures so high they can melt lead, winds that whip around it some 60 times faster than the planet itself rotates and an atmosphere that slams down with more than 90 times the pressure found on Earth’s atmosphere. But there have been a few tantalizing hints that billions of years ago Venus might have been more akin to Earth’s twin. ...But a few billion years ago a slightly fainter sun might have allowed for a relatively cool Venus, one where liquid water could have pooled in vast oceans that were friendly to life. A new study recently accepted in Geophysical Research Letters suggests that not only was Venus habitable in the distant past, it could have remained habitable for billions of years. Michael Way from NASA’s Goddard Institute for Space Studies and his colleagues applied the fir...

Source:   By Kevin Carey, WIRED. Excerpt: History will note that the guy who discovered liquid water on Mars was an undergraduate at the University of Arizona, a 20-year-old who played guitar in a death-metal band and worked in a planetary science lab. ...he noticed something odd: a set of dark streaks in the soil that grew in the Martian summer and shrank in the winter. They seemed to flow down the crater’s slope, like a spill. ...in September of 2015, [NASA] called a big press conference. It confirmed ... That was water in that crater. ...About a month after the press conference, a NASA administrator named Cassie Conley was sitting in her office, staring into her computer screen at a crudely designed website called UFO Sightings Daily. ...The item that Conley had come looking for was a photograph taken by the Curiosity rover and annotated by the website’s author. ...that streak in the soil descending from a crook between two rocks? The guy had labeled it “water.” And it reall...

Source:   By Randy Showstack, Earth & Space News EoS (AGU). Excerpt: The U.S. Federal Aviation Authority (FAA) announced on 3 August that on 20 July it had approved the first commercial space payload intended to land on the Moon. The agency granted a “favorable payload determination” for Moon Express, a privately funded commercial space company based in Moffett Field, Calif., to launch its coffee-table-sized robotic MX-1E spacecraft. The approval “is a landmark decision by the U.S. government and a pathfinder for private sector commercial missions beyond the Earth’s orbit.” said company cofounder and CEO Bob Richards. “We are now free to set sail as explorers to Earth’s eighth continent, the Moon, seeking new knowledge and resources to expand Earth’s economic sphere for the benefit of all humanity.” ...In 2014, NASA partnered with Moon Express and two other U.S. companies to advance lander capabilities to enable payload delivery to the surface of the Moon. In 2015, the compa...

Source:   By Daniel Clery, Science Excerpt: ...The planet hunt accelerated with the launch of NASA’s Kepler spacecraft in 2009, and the 2500 worlds it has discovered added statistical heft to the study of exoplanets—and yet more confusion. Kepler found that the most common type of planet in the galaxy is something between the size of Earth and Neptune—a “super-Earth,” which has no parallel in our solar system and was thought to be almost impossible to make.  ...Other planetary systems looked nothing like our orderly solar system, challenging the well-worn theories that had been developed to explain it. ...The traditional model of how stars and their planets form dates back to the 18th century, when scientists proposed that a slowly rotating cloud of dust and gas could collapse under its own gravity. ...This scenario naturally produces a planetary system just like our own: small, rocky planets with thin atmospheres close to the star, a Jupiter-like gas giant just beyond the...

Source:   NASA RELEASE 16-076 Excerpt: Using NASA’s Hubble Space Telescope, astronomers have conducted the first search for atmospheres around temperate, Earth-sized planets beyond our solar system and found indications that increase the chances of habitability on two exoplanets. ...the exoplanets TRAPPIST-1b and TRAPPIST-1c, approximately 40 light-years away, are unlikely to have puffy, hydrogen-dominated atmospheres usually found on gaseous worlds. ...The planets orbit a red dwarf star at least 500 million years old, in the constellation of Aquarius. They were discovered in late 2015 through a series of observations by the TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST), a Belgian robotic telescope located at ESA’s (European Space Agency’s) La Silla Observatory in Chile. TRAPPIST-1b completes a circuit around its red dwarf star in 1.5 days and TRAPPIST-1c in 2.4 days. The planets are between 20 and 100 times closer to their star than the Earth is to the sun. B...

Source:   Kenneth Chang, The New York Times Excerpt: Susan G. Finley began working on rockets before NASA existed. And now at age 79, instead of watching fireworks on the Fourth of July, she will be at her post in NASA’s Jet Propulsion Laboratory in Pasadena, Calif., waiting for confirmation that the latest of its space adventures has succeeded. Ms. Finley, an engineering specialist for the Deep Space Network of radio telescopes, will monitor radio signals, waiting for one critical beep — a signal sent from Juno , the solar-powered planetary explorer — that announces it has finally reached Jupiter , the largest planet in the solar system, after a five-year journey. [See also  NASA’s Juno Spacecraft Enters Into Orbit Around Jupiter  ] http://www.nytimes.com/2016/07/04/science/space/nasa-juno-susan-finley.html

Source:   By Kenneth Chang, New York Times Excerpt: After traveling for five years and nearly 1.8 billion miles, NASA’s Juno spacecraft will announce its arrival at Jupiter with the simplest of radio signals: a three-second beep. ...Juno’s mission is to explore the enigmas beneath the cloud tops of Jupiter. How far down does the Big Red Spot storm that has swirled for centuries extend? What is inside the solar system’s largest planet? ...“One of the primary goals of Juno is to learn the recipe for solar systems,” said Scott Bolton, a scientist at the Southwest Research Institute in San Antonio who is the principal investigator for the $1.1 billion mission. “How do you make the solar system? How do you make the planets in our solar system?”... http://www.nytimes.com/2016/06/28/science/nasa-jupiter-juno.html   See also  video  http://www.nytimes.com/video/science/100000004498333/juno-piercing-jupiters-clouds.html

Source:   By Bryan Lufkin, Scientific American Excerpt:  It will be the first spacecraft to probe deep below the planet’s thick cloud decks. ...the NASA orbiter will collect data that could elucidate the planet's origins and evolution, gather details about its long-lived storm (the Great Red Spot) and send back the highest-resolution color images of Jupiter to date. Jupiter was apparently born from the leftover gas and dust of the primordial nebula that formed our sun, yet exactly how that birth occurred, or even whether the planet has a solid core, is unknown. ...the NASA team has programmed the sensor-laden Juno to measure the chemical composition of the planet's atmosphere and to map its gravitational and magnetic fields. The craft's microwave radiometer will also “see” about 550 kilometers below the clouds covering Jupiter's surface. http://www.scientificamerican.com/article/nasa-s-juno-spacecraft-is-scheduled-to-arrive-at-jupiter-on-july-4/

Source:  The New York Times Excerpt:  Set foot on [Pluto] an alien world, three billion miles from the warmth of the sun. Download the NYT VR [virtual reality] app for Android or iPhone. [Different views are seen by moving the smart phone to different viewing angles. Or use cardboard viewer for effect]... http://www.nytimes.com/interactive/2016/05/19/science/space/seeking-plutos-frigid-heart-nytvr.html

Source:   By Shannon Hall, EoS-Earth & Space Science News (AGU) Excerpt: Massive meteorites likely slammed into a Martian ocean billions of years ago, unleashing tsunami waves up to 120 meters tall, a close study of a region of the Red Planet's terrain has found.... https://eos.org/articles/tsunamis-splashed-ancient-mars

Source:   By JoAnna Wendel, EoS-Earth & Space Science News (AGU) Excerpt: Scientists searching for life in the universe now have a new target: the once-icy worlds orbiting red giants. There’s some good news and bad news for Europa colonization enthusiasts. As our Sun gets older, brighter, and bigger over the next several billion years, it will expand into a red giant so large that its heat could melt ice on the surface of Europa and other moons of Jupiter, as well as those around Saturn. Liquid water flowing freely would not only be a boon for would-be space explorers, but it could provide a stable environment ripe for fostering life. The bad news is Earth will be burnt to a crisp. It may even get engulfed by the fiery wall of the expanding star, along with Mercury and Venus, so anyone that remains on Earth probably won’t live to see that day. For right now, however, humans who study planets orbiting other stars stand to benefit from the grim future prospects of our solar s...

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:  By Phil Plait, Bad Astronomy 2016-03-29. Jupiter Got Whacked by Yet Another Asteroid/Comet! By Phil Plait, Bad Astronomy. For GSS A Changing Cosmos chapter 1. Excerpt: On March 17, Gerrit Kernbauer, an amateur astronomer in Mödling, Austria, was taking video of Jupiter using a 20 cm telescope. ...he got more than he expected. At 00:18:33 UTC he captured what looks very much like the impact of a small comet or asteroid into Jupiter! [see video] ...On average ...an object will hit Jupiter with roughly five times the velocity it hits Earth, so the impact energy is 25 times as high. The asteroid that burned up over Chelyabinsk, Russia, in 2013 was 19 meters across, and it exploded with the energy of 500,000 tons of TNT. Now multiply that by 25, and you can see how it doesn’t take all that big a rock to hit Jupiter for us to be able to see it from Earth. Incidentally, at these huge speeds, hitting the atmosphere is like slamming into a wall. A lot of people get understanda...

Source:   By Glen Roberts Jr., Berkeley Lab News Center. Excerpt: WFIRST will explore mysteries of dark energy, hunt for distant planets, retrace universe's history during 6-year mission. ...The Wide Field Infrared Survey Telescope (WFIRST) will launch into its six-year mission from Cape Canaveral, Fla., in the mid-2020s. ...The telescope will be NASA’s next major astrophysics observatory following the launch of the James Webb Space Telescope in 2018. ...WFIRST is a 2.4-meter telescope with a primary mirror the same size as that of the Hubble Space Telescope. It has a field of view that is 100 times larger than Hubble’s infrared instrument and will measure light from an estimated billion galaxies. WFIRST is a 2.4-meter telescope with a primary mirror the same size as that of the Hubble Space Telescope. It has a field of view that is 100 times larger than Hubble’s infrared instrument and will measure light from an estimated billion galaxies.... http://newscenter.lbl.gov/2016/0...

Source:   By Adrian Cho, Science Excerpt: ...two massive black holes—the ultrastrong gravitational fields left behind by gigantic stars that collapsed to infinitesimal points—slowly drew together... spiraled ever closer, until, about 1.3 billion years ago, they whirled about each other at half the speed of light and finally merged. The collision sent a shudder through the universe: ripples in the fabric of space and time called gravitational waves. Five months ago, they washed past Earth. And, for the first time, physicists detected the waves, fulfilling a 4-decade quest and opening new eyes on the heavens. The discovery marks a triumph for the 1000 physicists with the Laser Interferometer Gravitational-Wave Observatory (LIGO), a pair of gigantic instruments in Hanford, Washington, and Livingston, Louisiana. ...Albert Einstein predicted the existence of gravitational waves 100 years ago, but directly detecting them required mind-boggling technological prowess ...[sensing] a wav...

Source:   By Ian Sample, The Guardian. Excerpt: Astronomers investigating the odd alignment of rocks beyond Pluto have concluded that an undetected icy planet four times the size of Earth must exist. ...If the researchers have their sums right, the mysterious new world is 10 times more massive than Earth and up to four times the size. Nicknamed Planet Nine, it moves on an extremely elongated orbit, and takes a staggering 10,000 to 20,000 years to swing once around the sun. ...Scientists at the California Institute of Technology (Caltech) calculate that the closest it comes to the sun is 15 times the distance to Pluto. It then heads into uncharted territory, 75 times further out than Pluto, or about 93 billion miles from the sun. A ray of light would take a week to get there. ...Chris Lintott... said ...“One very interesting thing is that the planet is predicted to be between Earth and Neptune in mass. We see lots of planets this size in our surveys of planets elsewhere in the g...