Kepler-186f

On Thursday (April 17), NASA announced the historic discovery of Kepler-186f, an alien planet 490 light-years from our own world that is nearly the size of Earth and located inside the habitable zone of its parent star.

The planet Kepler-186f was discovered by scientists using NASA's planet-hunting Kepler space telescope. The planet has a radius that is 1.1 times the radius of Earth, making it only slightly larger than our planet.

Main Story: Found! First Earth-Size Planet That Could Support LifeScientists have discovered Kepler-186f, the first Earth-size alien planet in the habitable zone of its host star. See how so-called 'Earth cousin' might have water, and possibly life. Scroll down for Space.com's complete coverage of the historic find of Kepler-186f.

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Upcoming 2013 ISON comet might be the brightest ever – set to shine as a full moon

Published on Mon, Jan 14, 2013 by 

Post filled By: Mangesh_More

Photograph of Comet West, one of the greatest comets of all-time, taken by an amateur astronomer. (c) John Laborde

Discovered last year by Russian astronomers Vitaly Nevsky and Artyom Novichonok, the gigantic ISON comet is set to make its appearance later this year as it approaches the sun when it will become visible to the naked eye during the day, and as bright as a full moon during the night.

Astronomers estimate the comet will reach its ‘perihelion passage’ – the closest point to the sun on the comet’s passage – in late November and will appear in the Northern hemisphere sky. Scientists fave found similarities between the ISON coment and that of the Great comet in 1680, also known as ‘Kirch’s Comet’ or ‘Newton’s Comet’, when it was reported to be bright enough to be seen in the daytime. Astronomers are expecting something similar from ISON.

Estimates are very difficult to make, since there are a lot of factors at play. The ISON comet might, for instance, break up in multiple smaller pieces that would significantly dim its brightness during its approach to the sun. Still, scientists hope ice particles will vaporize in the comet’s body, resulting in the massive, bright tail.

Popular astronomy author Guy Ottewell said in his 2013 Astronomical Calendar that the comet resembles “…a lighted match at the sun’s edge,” during the day. “Using what formulas we can for magnitude, we have it reaching -12.6, the brightness of the full moon!”

Comet C/2012 S1 (ISON) photographed at the RAS Observatory. (c) Remanzacco Observatory/Ernesto Guido, Giovanni Sostero & Nick Howes

Scientists have been able to track the origin of ISON to the Oort cloud, which is a bunch of frozen rock and ice which circles the sun at a distance which is 50,000 times larger than that of the Earth’s orbit or 1 light-year away. For those living in the Southern hemisphere, do not be too dishearten since you will still be able to enjoy Comet Pan-STARRS – a great astronomical event, thought maybe not as spectacular as ISON – which will be visible from January and reach its brightest in March.

UPDATE: video footage of the ISON comet passing through the solar system as captured by NASA’s Deep Impact spacracraft has been released.

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The end of Earth, the end of us, and the end of the universe

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Humanity is obsessed with history. I don’t know why, but for the most part we would much rather lose ourselves in reverie than contemplate the future. Even when we do think of the future, it’s nearly always constrained to our future, usually just a handful of years hence. It is a rare person indeed who thinks of 50 or 100 years in the future — but what about 1,000 years? Or a million years? Or a billion years?
Will humanity still exist? Will the Pyramids of Giza still exist? Will Earth or the Solar System exist?
The humbling, absolute truth is that human history makes up the tiniest of fraction of the universe’s history — and when you consider that the universe itself, at 14 billion years old, is still in its infancy, well… we don’t really have words to describe the utter flash-in-the-pan unimportance of humanity. The universe is 14 billion years old, the Earth is four billion years old, and Homo sapiens, humans, have existed for around 200,000 years. There are a few conflicting theories on what will happen to the universe in the long term, but the most likely theory — continued expansion until heat death occurs — is calculated to happen in 10¹⁰¹²⁰ years. This is a vast, vast number that you or I can’t even begin to comprehend; it’s 1, followed by 10¹²⁰ zeroes.
Long before the ultimate fate of the universe, though, all forms of life will cease to exist. In “just” 10⁴⁰ years (10 followed by 40 zeroes), the universe will enter the Black Hole Era, with almost all the matter in the universe forming black holes. After 10¹⁰⁰ years these black holes will evaporate and we will enter the Dark Era, where the universe will contain almost no matter at all. It is theorized that a handful of subatomic particles will bounce around for a few more gazillion years (until 10¹⁰¹²⁰), lose what energy they have left, and the universe will eventually decay into its final energy state — death.
But we’re getting ahead of ourselves! The timeline of the near far future is much more interesting, because our progeny might actually live to see it. For example, in 8,000 years, thanks to the Earth’s slowly shifting axial precession, Deneb will replace Polaris as the North Star. In 10,000 years, the Gregorian calendar will be 10 days out of sync with the sun’s position in the sky (and thus the seasons) — this is delightfully ironic, as the Gregorian calendar was originally implemented to fix a 10-day slippage caused by the Julian calendar. In 13,000 years, our axial precession will mean that Vega (a very bright star indeed!) becomes the North Star.
Looking a bit further out, in 40,000 years, Voyager 1 will retain the title of “farthest man-made object from Earth” and pass within 1.6 light years of AC+79 3888 (a star) — unless, of course, humanity develops a faster propulsion system before then. Moving at a velocity of 61,400 kilometers per hour (38,200mph), it takes Voyager 1 about 14,000 years to travel a single light year. Voyager 1 is perhaps most famous for taking the photo on the right, the Pale Blue Dot, at Carl Sagan’s behest. Here, Earth can be seen from six billion miles away as Voyager 1 leaves the Solar System.
After 50,000 years, assuming we can curb anthropogenic (human-based) global warming, the current interglacial is scheduled to end, throwing the Earth back into an ice age. Around this time, assuming nothing else changes, Niagara Falls should have eroded the remaining 20 miles to Lake Erie, and will cease to exist. (Presumably Lake Erie will freeze during the ice age, anyway.)
In 100,000 years, due to the continued (and very rapid movement) of stars in the sky, constellations will no longer be recognizable. Sometime after that, but before 1 million years have passed, Betelgeuse will go supernova. As one of the largest known stars, and at a distance of just 640 light years away from us, the supernova is expected to be visible during the day (that is, if any humans are around to see it).
In 1.4 million years, Gliese 710 is expected to pass by our Solar System, getting as close as 1.1 light years. Even at this distance, it won’t be a particularly bright star — but if we’re still stuck here on Earth (God help us), and assuming Gliese 710 has its own set of planets, this will be one of our best chances to populate another solar system.
Let’s take a quick breather. To put this all into perspective, remember that almost everything we’ve achieved here on Earth has taken place in the last 10,000 years, since the advent of modern civilization — and due to the acceleration of technology, a vast number of our achievements have occurred in just the last 200 years or so. In 1.4 million years, by the time Gliese 710 does a fly-by, human civilization will be indescribably advanced. 1.4 million years is more than long enough for a new species to emerge, too, so who knows, maybe Homo sapiens will have been ousted by Homo technicus, or something along those lines.

Continuing on, in 50 million years, the Californian coastline will begin to be subducted into the Aleutian Trench. In other tectonic news, after 50 million years, Africa will have collided with Eurasia, squashing the Mediterranean out of existence and creating a new mountain range, much like the Himalayas. After 250 million years, it’s possible that the continents will have (re-fused) back into a single supercontinent.
Between 250 million and 800 million years from now, Earth will slowly become uninhabitable, due to the Sun’s increasing luminosity (the old girl hasn’t reached her peak yet!) As temperatures rise, weathering increases, and the amount of carbon dioxide drops to a point where plants can no longer photosynthesize. 1 billion years from now, the Sun’s luminosity will have increased by 10%, resulting in an average Earth surface temperature of 47 degrees Celsius (117F). At this point, the oceans will evaporate into space, and shortly after, almost all remaining lifeforms will die.

From this point on, I guess it doesn’t really matter what happens to Earth, but just in case you’re wondering: In about 7.9 billion years, the Sun will reach its maximum radius — 256 times larger than it is today. At this point, it will absorb Mercury and Venus, and probably the Earth too. This is the end of the line for Earth. Shortly thereafter, the Sun will shrink down into a white dwarf, and then 6 billion years later it will (theoretically) become a black

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Structure and Evolution of Normal & Active Galaxies

Galactic structure and evolution is the study of whole galaxies as coherent, self-contained systems of dark matter, stars, and gas and how those systems change over billions of years of time. Like a living organism, the history of a galaxy is shaped by its internal metabolic processes (star formation and death, gravitational interactions among all its components, and sometimes by an active black hole engine at its core) as well as by interactions with other galaxies, its environment, and the universe itself. Understanding how galaxies, especially the Milky Way, formed and evolved is key to understanding an ancient part of mankind's own origins.

Typically a hundred thousand light years across and weighing a few hundred billion suns, each galaxy is home to most of the universe's many basic building blocks. These are the abundant but mysterious dark matter that dominates a galaxy's mass, interstellar gas and dust, stars and planets, neutron stars and black holes, and, often at the galaxy's center, an active supermassive black hole engine that may outshine the combined light from all its stars.

On the "small' scale, galaxy evolution is influenced by the death of old stars, which expel newly-created elements forged in their central furnaces, as well as the formation of new stars from the enriched interstellar gas. This keeps the stellar population replenished over eons of time. A galaxy's shape is determined by how the stars and gas move within the gravitational field of the galaxy's (mostly dark) matter, and the rate at which it forms stars is determined by how much interstellar gas it has.

Occasionally, two galaxies collide and merge, leading initially to a rapid increase in the rate of star formation and a rapid funneling of gas fuel to the supermassive black hole engine in the center. This active galactic nucleus (or AGN) sometimes shines so brightly that all we can see on earth is a quasar at its center. In fact, the radiation pressure and powerful jets generated by the AGN can drive out all the gas accreted in the merger, thereby shutting off the supply of gas that fueled star formation and nuclear activity in the first place.

On the very large scale, galaxies appear to have formed out of the expanding universe shortly after the Big Bang. So the study of galaxy evolution requires understanding not only star formation and supermassive black holes, but also Cosmology --- the birth and evolution of the universe itself.

Selected Current Projects

Spitzer Telescope

The high redshift (z = 1.070) galaxy cluster ISCS J1433.1+3334 at a distance of about 7.9 billion light years. The boxed and circled objects are galaxies in this cluster.

In addition to studying the Origin of Stars and Planets, the Spitzerinfrared observatory also is used to study galaxies at distances so great that we are seeing them as they were billions of years ago. All light from these galaxies is redshifted by the expansion of the universe to about twice its normal wavelength. (For example, the emission line of doubly-ionized oxygen and the Hα line of neutral hydrogen [0.501 and 0.656 micron wavelengths, respectively] are redshifted to over 1.0 and 1.3 microns.) So, whereas local galaxies can be studied at optical wavelengths, it is better to study "high redshift" galaxies in the infrared.

Recently the Spitzer telescope's InfraRed Array Camera (IRAC) was used to search for clusters of galaxies nearly 8 billion light years away. In addition to discovering 335 new young galaxy candidates, the study also determined that the total mass of some of the clusters in which they lie weight more than 100 trillion suns each! Detailed studies of the stars in these galaxies indicate that they formed shortly after the Big Bang, over 11 billion years ago.

The Spitzer IRAC instrument also was used to look at over 3000 galaxies with very strong X-ray emission. It was found that in at least 90% of these galaxies the X-ray and infrared emission is coming from an active nucleus, i.e., a brightly emitting supermassive black hole engine at the center of the galaxy.

The Deep Space Network Ground Radio Telescopes

While the main job of NASA’s Deep Space Network is to track distant spacecraft like Voyager, Cassini, and Spitzer, these communication antennas also can be used as ground radio telescopes - either as single dishes or as some of the most powerful elements in world-wide Very Long Baseline Interferometry (VLBI) arrays, which also may include a space radio telescope as well (Space VLBI).

Artist’s conception of the central few light years of the active galaxy NGC 4258. The black hole lies at the center and produces a jet. A warped disk of molecular gas encircles the hole and produces masers in the direction of the earth (bright white spots on the disk). The radio spectrum at the bottom, indicating the velocities of the masers away from the earth, shows that the gas indeed orbits the black hole just like the planets orbit our sun (i.e., in a Keplerian-type orbit).

Astronomical masers (microwave lasers) are regions of interstellar (or circumstellar) gas where radio emission of a particular molecular transition piles up in one direction, producing an extremely bright source toward that one direction. Occasionally some of these focused emissions point toward the earth. Masers of OH, SiO, methanol, and other molecules are common in giant molecular cloud regions where stars form. In addition, enormously bright water megamasers often occur in the centers of mildly active galaxies (AGN), in the warm dense molecular gas that circles within a couple of light years of the central supermassive black hole. By measuring the detailed motions of water megamaser spots we can measure very accurately not only the mass of the central black hole, but also the distance of the galaxy from earth.

Recently NASA’s Deep Space Network antennas were used to find eight new water megamasers in the centers of nearby and moderately distant galaxies. This has significantly increases the number, and distance, of known megamasers. Further studies of these systems with VLBI and Space VLBI will help determine an accurate distance scale to the universe - the so-called Hubble constant.

NASA-Funded Theoretical Investigations

The behavior of normal and active galaxies also can be studied with supercomputers and other forms of theoretical calculation. Indeed, it is with such studies, and detailed comparison with observations, that the greatest understanding of these objects is achieved. Similar to weather prediction or airplane aerodynamic studies on the earth, these astrophysical simulations build galaxy or black hole systems inside a supercomputer’s memory and use the laws of physics to determine how the system evolves. Sometimes the simulation follows the flow of cosmic fluid or the interaction of hundreds of thousands of star and dark matter "particles."

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Soyuz Spacecraft Returning to Earth with US-Russian Crew

A Soyuz spacecraft has undocked from the International Space Station and is preparing to descend into Earth's atmosphere to return an American astronaut and two Russian cosmonauts back home after nearly five months living in orbit.
The undocking tonight (March 15) occurred smoothly, but one day later than planned, due to freezing rain and fog at the Soyuz's landing site on the steppes of Kazakhstan in Central Asia, which delayed the departure. Returning home on the Soyuz are NASA astronaut Kevin Ford and Russian cosmonauts

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New update on comet C/2011 L4 (PANSTARRS)

Comet C/2011 L4 (PANSTARRS), discovered by Pan-STARRS 1 telescope on Haleakala, Maui, on the night of 2011, June 5-6, will reach perihelion in March 2013 when it will be located only 0.30 AU from the Sun and might become a bright naked eye object ( with a peak magnitude of anywhere from +1 to -1). At its brightest C/2011 L4 will appear only 15° from the Sun.

The comet is now at 3.2 AU from the Sun (m2 ~ 14.0). While visually C/2011 L4 is at m1 ~ 11.

We performed some follow-up measurements of comet C/2011 L4 remotely from the Siding Spring-Faulkes Telescope South on 2012, September 10.4 through a 2.0-m f/10.0 Ritchey-Chretien + CCD. Below you can see our follow-up image (click on it for a bigger version):

Below you can see the lightcurve of comet C/2011 L4 (PANSTARRS) collected by Seiichi Yoshida on his comet webpage: 

                                  (Credit: Seiichi Yoshida)

As a comparison, below you can see our image of the comet taken on June 7.4, 2011 just one day after his discovery by Pan-STARRS Survey. The comet was then at 8.2 AU from the Sun (m2 ~ 19.5).

While below there is our image taken on May 18.6, 2012 with the comet at 4.6 AU from the Sun (m2 ~ 15.6).

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Mars Science Laboratory

Different Tools for Different Purposes on Mars

This set of images from Mars shows the handiwork of different tools on three missions to the surface of Mars. The action of each of the tools has sometimes been referred to as drilling, but the functions of the tools have been different for each mission.

On the left is a rock on which NASA's Mars Exploration Rover Opportunity used the rock abrasion tool on the rover's robotic arm. Opportunity and its twin, Spirit, were each equipped with one of these tools to grind away the surface layer of rocks and expose interior rock material to examination, in place, by instruments on the rover. The diameter of the abraded circle is 1.8 inches (4.5 centimeters) in diameter. The image was cropped from PIA06355, taken in June 2004 by Opportunity's Panoramic Camera at a target called "London" inside Endurance Crater.

The middle image shows a grid of shallow holes cut into icy soil by NASA's Phoenix Mars Lander using the motorized rasp on the back of the scoop on the lander's robotic arm. Phoenix used the rasp to penetrate frozen soil too hard for just scraping with the front-edge blade of the scoop. Soil shavings generated by the rasp were picked up by the scoop for delivery into the lander's analytical instruments. The grid of rasped holes visible in this image, four holes across, is about 2 inches (5 centimeters) wide. The image was cropped from PIA10981, taken in July 2008 by Phoenix's Surface Stereo Imager of a trench called "Snow White."

On the right is the hole produced by the drill on NASA's Mars rover Curiosity during the first drilling into a rock on Mars to collect a sample from inside the rock. Flutes on the bit of the drill on Curiosity's robotic arm transport powdered material generated by drilling up into the drill, for later processing and delivery into analytical instruments inside the rover. The diameter of the hole is 0.63 inch (1.6 centimeters). The image was cropped from PIA16726, taken Feb. 8, 2013, by the Mars Hand Lens Imager on Curiosity's arm after that day's drilling at a target rock called "John Klein."

Views of Curiosity's Drill

These schematic drawings show a top view and a cutaway view of a section of the drill on NASA's Curiosity rover on Mars. The section view on the right also indicates the flow of material within the drill bit.

Image credit: NASA/JPL-Caltech

Preparation on Earth for Drilling on Mars

The development of the Mars rover Curiosity's capabilities for drilling into a rock on Mars required years of development work. This is a group photo of some of the rocks used in bit development testing and lifespan testing in 2007, at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Most of the holes are the same diameter as holes Curiosity drills: 0.63 inch (1.6 centimeters).

Development and testing models of drills for Curiosity have been used on many types of terrestrial rocks over a span of more than five years.

Image credit: NASA/JPL-Caltech

Tracks from Eastbound Drive on Curiosity's Sol 22

On Aug. 28, 2012, during the 22nd Martian day, or sol, after landing on Mars, NASA's Curiosity rover drove about 52 feet (16 meters) eastward, the longest drive of the mission so far. The drive imprinted the wheel tracks visible in this image. The rover's rear Hazard Avoidance Camera (Hazcam) took the image after the drive. Curiosity's front and rear Hazcams have fisheye lenses for enabling the rover to see a wide swath of terrain. This image has been processed to straighten the horizon.

Image credit: NASA/JPL-Caltech

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