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aamukherjee A Slice of Entropie -
alchymista Alchymista -
crownedrose Fading Like A Dead Star -
expose-the-light Quarks to Quasars -
kenobi-wan-obi CWL -
abluegirl A Blue Girl -
perscientiamlibertas A Matter of the Most Pleasant Fraternal Confidence
An Incredibly Hostile Universe
Astronomer Steve Vogt describes his search for extrasolar and Earth-like planets at the Lick Observatory.
“The first habitable planet that we’ve found, Gliese 581G, is right dead-on inhabitable on orbit. It’s a place of refuge from the — the unbelievable harshness of the universe. A place where you could stand and not, you know, fly off into space, where there would be gases to breath, water that would pool in liquid form, maybe oceans. Whether there’s something living there or not, we don’t know.”
ucresearch
At an average distance of 2.8 billion miles from the sun, Neptune generates more heat itself than it absorbs from sun. That heat creates massive storms and winds going up to 900 miles an hour.
kenobi-wan-obiThere may be a hundred billion planetary systems in the galaxy awaiting exploration. Not one of those worlds will be identical to Earth. A few will be hospitable; most will appear hostile. Many will be achingly beautiful. In some wolds there will be many suns in the daytime sky, many moons in the heavens at night, or great particle ring systems soaring from horizon to horizon. Some moons will be so close that their planet will loom high in the heavens, covering half the sky. And some worlds will look out into a vast gaseous nebula, all those skies, rich in distant and exotic constellations, there will be a faint yellow star — perhaps barely seen by the naked eye, perhaps visible only through the telescope — the home star of the fleet of interstellar transports exploring this tiny region of the Milky Way Galaxy.
The themes of space and time are, we have seen, intertwined. Worlds and stars, like people, are born, live and die. The lifetime of a human being measured in decades; the lifetime of the Sun is a hundred million times longer. Compared to a star, we are like mayflies, fleeting ephemeral creatures who live out their whole lives in the course of a single day. From the point of view of a mayfly, human beings are stolid, boring, almost entirely immovable, offering hardly a hint that they ever do anything. From the point of view of a star, a human being is a tiny flash, one of the billions of brief lives flickering tenuously on the surface of a strangely cold, anomalously solid, exotically remote sphere of silicate and iron.
In all these other worlds in space there are events in progress, occurrences that will determine their futures. And on our small planet, this moment in history is a historical branch point as profound as the confrontation of the Ionian scientists with the mystics 2,500 years ago. What we do with our world in this time will propagate down though the centuries and powerfully determine the destiny of our descendants and their fate, if any, among the stars.
There may be a hundred billion planetary systems in the galaxy awaiting exploration. Not one of those worlds will be identical to Earth. A few will be hospitable; most will appear hostile. Many will be achingly beautiful. In some wolds there will be many suns in the daytime sky, many moons in the heavens at night, or great particle ring systems soaring from horizon to horizon. Some moons will be so close that their planet will loom high in the heavens, covering half the sky. And some worlds will look out into a vast gaseous nebula, all those skies, rich in distant and exotic constellations, there will be a faint yellow star — perhaps barely seen by the naked eye, perhaps visible only through the telescope — the home star of the fleet of interstellar transports exploring this tiny region of the Milky Way Galaxy.
The themes of space and time are, we have seen, intertwined. Worlds and stars, like people, are born, live and die. The lifetime of a human being measured in decades; the lifetime of the Sun is a hundred million times longer. Compared to a star, we are like mayflies, fleeting ephemeral creatures who live out their whole lives in the course of a single day. From the point of view of a mayfly, human beings are stolid, boring, almost entirely immovable, offering hardly a hint that they ever do anything. From the point of view of a star, a human being is a tiny flash, one of the billions of brief lives flickering tenuously on the surface of a strangely cold, anomalously solid, exotically remote sphere of silicate and iron.
In all these other worlds in space there are events in progress, occurrences that will determine their futures. And on our small planet, this moment in history is a historical branch point as profound as the confrontation of the Ionian scientists with the mystics 2,500 years ago. What we do with our world in this time will propagate down though the centuries and powerfully determine the destiny of our descendants and their fate, if any, among the stars.
This new global view of Earth’s city lights is a composite assembled from data acquired by the Suomi National Polar-orbiting Partnership (NPP) satellite.
Credit: NASA’s Earth Observatory/NOAA/DOD
The data was acquired over nine days in April 2012 and 13 days in October 2012. It took 312 orbits to get a clear shot of every parcel of Earth’s land surface and islands. This new data was then mapped over existing Blue Marble imagery of Earth to provide a realistic view of the planet.
The image was made possible by the satellite’s “day-night band” of the Visible Infrared Imaging Radiometer Suite, which detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe dim signals such as city lights, gas flares, auroras, wildfires and reflected moonlight.
The day-night band observed Hurricane Sandy, illuminated by moonlight, making landfall over New Jersey on the evening of Oct. 29. Night images showed the widespread power outages that left millions in darkness in the wake of the storm.
Exoplanet Catalog Reveals 7 Possibly Habitable Worlds
A new catalog aims to list all the known planets in the galaxy that could potentially be habitable to life. The count is at seven so far, with many more to come, researchers said.
Image: More exoplanets than expected in the first year of the Habitable Exoplanets Catalog. Image released Dec. 6, 2012. Credit: PHL @ UPR Arecibo, ESA/Hubble, NASA
The online listing, called the Habitable Exoplanets Catalog, celebrated its first anniversary today (Dec. 5). When it was first released last year, it had two potential habitable planets to its name. According to lead researcher Abel Mendez, the team expected to add maybe one or two more in the catalog’s first year. The addition of five suspected new planets was wholly beyond anyone’s expectations.
“The main purpose is for research, but then I realized that also for the public, it was very important,” said Mendez, director of the University of Puerto Rico at Arecibo’s Planetary Habitability Laboratory.
(via kenobi-wan-obi)
Tethys may not be tiny by normal standards, but when it is captured alongside Saturn, it can’t help but seem pretty small.
Even Saturn’s rings appear to dwarf Tethys (660 miles, or 1,062 kilometers across), which is in the upper left of the image, although scientists believe the moon to be many times more massive than the entire ring system combined.
This view looks toward the unilluminated side of the rings from about 18 degrees below the ringplane. The image was taken in green light with the Cassini spacecraft wide-angle camera on Aug. 19, 2012.
HiRISE Updates: Fresh New Batch of Gorgeous Geological Art from Mars
1. Stunning Landscape Near Mamers Valles: This region of Mars has been long studied for its evidence of glacial-like flow features. The landscape is dominated by flat top mesas and flat valley floors. But a closer look shows evidence that soil material is flowing ever so gradually from the edges of the mesas out into the valleys.
2. Layers in Northeast Sinus Meridiani: The objective of this image is to examine the exposure of thin layers along the walls of a few-kilometer-wide valley in Sinus Meridiani.
3. Martian Mélange: “Mélange” means a confusing mixture, and is used to describe rocks scraped off the top of a downward-moving tectonic plate in a subduction zone on Earth. On Mars it is probably mostly impact cratering that creates such chaotic mixture of rock types rather than plate tectonics.
The false colors in this image indicate altitude.
Credit: Erich Karkoschka (University of Arizona) and NASA
The green and blue regions show where the atmosphere is clear, allowing sunlight to penetrate deep into Uranus. In the yellow and gray regions, a haze or cloud layer is reflecting sunlight away. Orange and red colors indicate very high clouds, like cirrus clouds on Earth.
Dwarf Planets of Our Solar System
— In 2006 the organization responsible for classifying celestial bodies, the International Astronomical Union, decided that a new class of objects was needed. The solar system’s erratic ninth planet, Pluto, was assigned to the new “dwarf planet” category along with four other bodies, all tinier than Earth’s moon. Some astronomers expect there may be as many as 50 dwarf planets in the solar system.
— Eris, the largest dwarf planet, is only slightly bigger than Pluto, at 1,445 miles in diameter (2,326 km). Discovered in 2003, Eris orbits at an average distance of 68 AU (that is, 68 times the Earth’s distance from the sun) and takes 561.4 Earth years to circle the sun. Eris has the orbit that is most highly inclined of all the dwarf planets, tilted nearly 47 degrees from the plane of the planets’ orbits. A day on Eris takes 25.9 hours. Eris has one moon, Dysnomia.
— Pluto, discovered in 1930, orbits the sun at an average of 39.5 times the Earth’s distance. Its diameter is 1,430 miles (2,302 km). Pluto takes 247.9 Earth years to orbit the sun, and its day is 6.39 times as long as Earth’s. Pluto has five known moons: Charon, Nix, Hydra and two that were recently discovered and have not yet been named.
— Haumea was discovered in 2003. This dwarf planet has an extremely elongated shape, with its longest dimension being about 1,218 miles long (1,960 km). Haumea rotates very rapidly and has the shortest day of all the dwarf planets, only 3.9 hours. Orbiting 43.1 times farther from the sun than Earth does, Haumea takes nearly 282 Earth years to complete one orbit. Haumea has two moons, Hi’iaka and Namaka.
— Makemake, discovered in 2005, has no known moons. Makemake orbits at 45.3 times Earth’s distance and takes more than 305 years to complete a circuit of the sun. Its day is 22.5 hours. Makemake’s average diameter is 882 miles (1,420 km).
— Ceres, first spotted by astronomers in 1801, was first called a planet and later an asteroid. In 2006 it was reclassified as a dwarf planet. Ceres is the closest dwarf planet to Earth, orbiting at only 2.8 times Earth’s distance from the sun. Its year takes 4.6 Earth years and its day is 9.1 hours. Ceres has no known moons.
‘Super-Jupiter’ Discovery Dwarfs Solar System’s Largest Planet
Astronomers have spotted a planet 13 times more massive than Jupiter, the largest planet in our own solar system.
Image: The “super-Jupiter” Kappa Andromedae b, shown here in an artist’s rendering, circles its star at nearly twice the distance that Neptune orbits the sun. With a mass about 13 times Jupiter’s, the object glows with a reddish color. Credit: NASA’s Goddard Space Flight Center/S. Wiessinger
The planet orbits a star called Kappa Andromedae that is 2.5 times the mass of the sun and is located 170 light-years away from Earth. As a gas giant larger than Jupiter, it’s classified as a “super-Jupiter.”
Astronomers say the object’s immense size places it right on the edge of the classifications for giant planets and a type of failed star known as a brown dwarf. Its official name is Kappa Andromedae b, or Kappa And b for short, and it likely has a reddish glow, researchers said.
“According to conventional models of planetary formation, Kappa And b falls just shy of being able to generate energy by fusion, at which point it would be considered a brown dwarf rather than a planet,” Michael McElwain, a member of the discovery team at NASA’s Goddard Space Flight Center in Greenbelt, Md., said in a Nov. 19 statement. “But this isn’t definitive, and other considerations could nudge the object across the line into brown dwarf territory.”
NASA’s Prolific Planet-Hunting Mission Goes Into Overtime
NASA’s planet-hunting Kepler Space Telescope has begun its extended mission, which should keep the prolific instrument searching for alien worlds for another four years, agency officials announced today (Nov. 14).
Kepler officially embarked upon the extended mission after completing its 3 1/2-year prime mission, which aimed to determine how common Earth-like planets are throughout the galaxy. The extended phase, which NASA announced this past April, funds the instrument through at least fiscal year 2016.
Kepler is staring at more than 150,000 stars continuously. It detects exoplanets by noticing the tiny brightness dips caused when they transit — or cross the face of — these stars from the telescope’s perspective.
NASA’s Prolific Planet-Hunting Mission Goes Into Overtime
NASA’s planet-hunting Kepler Space Telescope has begun its extended mission, which should keep the prolific instrument searching for alien worlds for another four years, agency officials announced today (Nov. 14).
Kepler officially embarked upon the extended mission after completing its 3 1/2-year prime mission, which aimed to determine how common Earth-like planets are throughout the galaxy. The extended phase, which NASA announced this past April, funds the instrument through at least fiscal year 2016.
Kepler is staring at more than 150,000 stars continuously. It detects exoplanets by noticing the tiny brightness dips caused when they transit — or cross the face of — these stars from the telescope’s perspective.
Artist’s Concept of Kepler-20e
NASA’s Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system. The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in the so-called habitable zone where liquid water could exist on a planet’s surface, but they are the smallest exoplanets ever confirmed around a star like our sun.
Kepler-20e is the first planet smaller than the Earth discovered to orbit a star other than the sun. A year on Kepler-20e only lasts 6 days, as it is much closer to its host star than the Earth is to the sun. The temperature at the surface of the planet, around 1400 degrees Fahrenheit, is much too hot to support life, as we know it.
Kepler-20e is likely to be entirely rocky and without an atmosphere. The planet is tidally locked, always showing the same side to its host star, as the moon to the Earth, and could have large temperature differences between its permanent night and day sides.
