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WIRED: A Total Solar Eclipse Feels Really Really Weird

WIRED: A Total Solar Eclipse Feels Really Really Weird | Amazing Science | Scoop.it
During the minutes during which the sun is completely blocked, observers experience the exquisitely odd and wondrous sensation of solar emissions, both visible and invisible, vanishing right in the middle of the day.
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The sun's core rotates four times faster than its surface

The sun's core rotates four times faster than its surface | Amazing Science | Scoop.it

We don’t know much about the early history of the sun but a surprising discovery might change that. According to an international team of astronomers, the sun’s core actually spins four times faster than its surface. Previously, astronomers presumed the core was simply rotating at the same pace with its surface like a unitary body. What happened instead though was that solar wind steadily slowed down the rotation of the outer part of the sun.  “The most likely explanation is that this core rotation is left over from the period when the sun formed, some 4.6 billion years ago,” said Roger Ulrich, a UCLA professor emeritus of astronomy, who has studied the sun’s interior for more than 40 years and co-author of the study that was published today in the journal Astronomy and Astrophysics. “It’s a surprise, and exciting to think we might have uncovered a relic of what the sun was like when it first formed.”

 

The sun is comprised of four distinct layers. Energy is generated in the core, the innermost one, then blasts outward by radiation (mostly gamma-rays and x-rays) through the radiative zone and by convective fluid flows (boiling motion) through the convection zone, the outermost layer. The thin interface layer (the “tachocline”) between the radiative zone and the convection zone is where the sun’s magnetic field is thought to be generated.

 

Ulrich and colleagues learned this after they studied surface acoustic waves that hit the sun’s surface, some of which also penetrated the core. Once at the core, the acoustic waves interact with gravity waves whose motion resembles water bouncing back and forth in a half-filled tanker truck taking a curve. This interaction ultimately revealed the sloshing motions of the solar and by accurately measuring the acoustic waves, the team found out the time required for the waves to travel from the surface to the core and back.

This effort required 16 years of coordinated action by many research institutes to bring to fruition.

 

Since two decades ago, some scientists have been proposing that the sun’s core rotates slower than its surface but it was only recently that the tech enabled an investigation. Instruments like GOLF (Global Oscillations at Low Frequency) on a spacecraft called SoHO proved to be essential, for instance.

 

It makes sense that the core and the surface of the sun can have such dissimilar properties. For one, the core — where nuclear fusion occurs — has a temperature of 15.7 million Kelvin while the surface is far, far colder measuring only 5,800 Kelvin in temperature. And as an interesting trivia — just to get an idea of the complexities involved in the many layers between the core and surface of the sun — by the most recent estimates, it takes about a million years for photons forged in the core to escape through the surface. From there, it only takes them eight minutes to reach Earth.

 

The findings appeared in the journal Astronomy & Astrophysics.

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Cassini’s Final Five Orbits

Cassini’s Final Five Orbits | Amazing Science | Scoop.it

NASA’s Cassini spacecraft will enter new territory in its final mission phase, the Grand Finale, as it prepares to embark on a set of ultra-close passes through Saturn’s upper atmosphere with its final five orbits around the planet.

 

Cassini will make the first of these five passes over Saturn at 12:22 a.m. EDT Monday, Aug. 14, 2017. The spacecraft’s point of closest approach to Saturn during these passes will be between about 1,010 and 1,060 miles (1,630 and 1,710 kilometers) above Saturn’s cloud tops.

 

The spacecraft is expected to encounter atmosphere dense enough to require the use of its small rocket thrusters to maintain stability – conditions similar to those encountered during many of Cassini’s close flybys of Saturn’s moon Titan, which has its own dense atmosphere.

 

“Cassini’s Titan flybys prepared us for these rapid passes through Saturn’s upper atmosphere,” said Earl Maize, Cassini project manager at NASA’s Jet Propulsion Laboratory (JPL) in California. “Thanks to our past experience, the team is confident that we understand how the spacecraft will behave at the atmospheric densities our models predict.”

 

Maize said the team will consider the Aug. 14 pass nominal if the thrusters operate between 10 and 60 percent of their capability. If the thrusters are forced to work harder – meaning the atmosphere is denser than models predict – engineers will increase the altitude of subsequent orbits. Referred to as a “pop-up maneuver,” thrusters will be used to raise the altitude of closest approach on the next passes, likely by about 120 miles (200 kilometers).

 

If the pop-up maneuver is not needed, and the atmosphere is less dense than expected during the first three passes, engineers may alternately use the “pop-down” option to lower the closest approach altitude of the last two orbits, also likely by about 120 miles (200 kilometers). Doing so would enable Cassini’s science instruments, especially the ion and neutral mass spectrometer (INMS), to obtain data on the atmosphere even closer to the planet’s cloud tops.

 

“As it makes these five dips into Saturn, followed by its final plunge, Cassini will become the first Saturn atmospheric probe,” said Linda Spilker, Cassini project scientist at JPL. “It’s long been a goal in planetary exploration to send a dedicated probe into the atmosphere of Saturn, and we’re laying the groundwork for future exploration with this first foray.”

 

Other Cassini instruments will make detailed, high-resolution observations of Saturn’s auroras, temperature, and the vortexes at the planet’s poles. Its radar will peer deep into the atmosphere to reveal small-scale features as fine as 16 miles (25 kilometers) wide – nearly 100 times smaller than the spacecraft could observe prior to the Grand Finale.

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Huge bright storm the size of Earth on Neptune

Huge bright storm the size of Earth on Neptune | Amazing Science | Scoop.it

A storm complex nearly the size of Earth has been seen in a usually quiet area of Neptune. Ned Molter from the University of California, Berkeley in the US spotted the storm while performing a test run of twilight observing at the W M Keck Observatory in Hawaii.

 

The storm system appears as a very bright region about 9000 km in length and spans at least 30° in both latitude and longitude. "Seeing a storm this bright at such a low latitude is extremely surprising," explains Molter. "Normally, this area is really quiet and we only see bright clouds in the mid-latitude bands, so to have such an enormous cloud sitting right at the equator is spectacular."

 

As on all planets, Neptune's atmospheric winds vary greatly with latitude. For the storm system to span so many degrees, there therefore has to be something holding it together. A possible explanation is a huge, high-pressure vortex system anchored deep in the planet's atmosphere. Just like water-vapour-forming clouds on Earth, methane gas on Neptune would cool and condense into clouds as it rises up the vortex.

 

Alternatively, the bright system could be a huge convective cloud, as seen on other planets such as Saturn. With this scenario, however, Neptune's storm would likely have smeared out over the course of a week, but Molter observed it getting brighter between 26 June and 2 July.

 

"This shows that there are extremely drastic changes in the dynamics of Neptune's atmosphere, and perhaps this is a seasonal weather event that may happen every few decades or so," says Imke de Pater, also from the University of California, Berkeley.

 

Understanding Neptune's atmosphere is becoming increasingly important with regards to exoplanets, as the majority resemble the ice giant. Molter and de Pater hope to investigate the storm system further with more twilight observation runs at the Keck Observatory.

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First images from Lockheed's experimental, telescope-shrinking SPIDER

First images from Lockheed's experimental, telescope-shrinking SPIDER | Amazing Science | Scoop.it

Shrinking the telescope: The experimental SPIDER optical instrument developed by Lockheed Martin could usher in ultra-thin devices that weigh 90 percent less than typical telescopes while providing equivalent resolution. The first images captured by the device have now been revealed.

 

Telescopes could dramatically shrink in the future with a gen-after-next technology called SPIDER. A thin, scalable array of tiny lenslets piece together visual information like a jigsaw puzzle—a science called interferometry—and will eliminate all the bulk of traditional telescopes. Lighter instruments that are faster to build mean cheaper launches, multi-mission spacecraft and even benefits down here on Earth.

 

SPIDER was originally developed for DARPA by Lockheed's research partners at the University of California, Davis, and independently advanced by Lockheed at its Advanced Technology Center (ATC). Unlike conventional telescopes, which rely on lenses or mirrors, SPIDER replaces the primary lens with a thin array of tiny, insect-like lenses. Each of these lenses feeds light to a silicon-chip photonic integrated circuit (PIC), so the telescope is essentially a bank of still cameras.

 

These images are combined using the principle of interferometry. This is where the light waves from the array images interferes with one another, and by analyzing the amplitude and phase of the interference patterns, a processor can generate a new image of much higher resolution.

 

This technology allows for ultra-thin, flat telescopes with arrays of photonic sensors. For the released images, Lockheed created an array of 30 lenses that are each less than a millimeter wide. These were placed in an optical system using a 4-ft (1.2-m) mirror assembly to simulate a distance of 280 mi (450 km) when capturing images of two test targets: a standard bar test pattern and an overhead view of a complex railway yard.

 

Lockheed says that when the technology is mature it could be used to make space telescopes as efficient as conventional ones, but will allow for a significant reduction in payload weight. In addition, it can be used on aircraft, drones, and cars, where the sensors can be installed flush under wings or in radiator grilles.

 

The next phase of development will concentrate on assembling a larger instruments with higher resolution and wider fields of view.

 

Video is here

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Rogue "Double Planet" Proves to Be Two Failed Stars

Rogue "Double Planet" Proves to Be Two Failed Stars | Amazing Science | Scoop.it
The two co-orbiting brown dwarfs drift between the stars 95 light-years from Earth, and form the lightest binary system ever found

 

A pair of objects drifting in interstellar space may look like a rogue “double planet,” but it's actually two failed stars, a new study finds.The duo is the most lightweight binary system ever discovered and may be the closest approximation of a free-floating “double planet” that astronomers have found so far. The object, named 2MASS J11193254−1137466, is located about 95 light-years from Earth, in the constellation Hydra. A 2016 study suggested it was a free-floating planet-like body — a “rogue” object without a parent star. 

 

This previous research estimated that the mass of this object, also known as 2M1119, was four to eight times that of Jupiter. This suggested it was abrown dwarf, also known as a failed star.

 

[Brown Dwarfs: Strange Failed Stars of the Universe Explained (Infographic)]

 

Brown dwarfs, like regular stars, begin as clouds of gas and dust that collapse under their own gravity. However, brown dwarfs lack the mass to squeeze atoms enough to trigger nuclear fusion. Instead, they are not quite planets and not quite stars. Now, with the aid of the Keck II telescope in Hawaii, scientists have found that 2M1119 is actually two brown dwarfs, of equal brightness, orbiting each other.

 

“The fact that it was a binary, not another boring single system, was completely new,” study co-author Trent Dupuy, an astronomer at the University of Texas at Austin, told Space.com. “Maybe it means that planetary-mass objects can form like stars and also, very rarely, form like binary stars.”

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Astrophysicists map out the light energy contained within the Milky Way

Astrophysicists map out the light energy contained within the Milky Way | Amazing Science | Scoop.it

For the first time, a team of scientists have calculated the distribution of all light energy contained within the Milky Way, which will provide new insight into the make-up of our galaxy and how stars in spiral galaxies such as ours form. The study is published in the journal Monthly Notices of the Royal Astronomical Society.

 

This research, conducted by astrophysicists at the University of Central Lancashire (UCLan), in collaboration with colleagues from the Max Planck Institute for Nuclear Physics in Heidelberg, Germany and from the Astronomical Institute of the Romanian Academy, also shows how the stellar photons, or stellar light, within the Milky Way control the production of the highest energy photons in the Universe, the gamma-rays. This was made possible using a novel method involving computer calculations that track the destiny of all photons in the galaxy, including the photons that are emitted by interstellar dust, as heat radiation.

 

Previous attempts to derive the distribution of all light in the Milky Way based on star counts have failed to account for the all-sky images of the Milky Way, including recent images provided by the European Space Agency's Planck Space Observatory, which map out heat radiation or infrared light.

 

Lead author Prof Cristina Popescu from the University of Central Lancashire, said: "We have not only determined the distribution of light energy in the Milky Way, but also made predictions for the stellar and interstellar dust content of the Milky Way."

 

By tracking all stellar photons and making predictions for how the Milky Way should appear in ultraviolet, visual and heat radiation, scientists have been able to calculate a complete picture of how stellar light is distributed throughout our Galaxy. An understanding of these processes is a crucial step towards gaining a complete picture of our Galaxy and its history.

 

The modeling of the distribution of light in the Milky Way follows on from previous research that Prof Popescu and Dr Richard Tuffs from the Max Planck Institute for Nuclear Physics conducted on modeling the stellar light from other galaxies, where the observer has an outside view.


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The Resilience of Life to Astrophysical Events

The Resilience of Life to Astrophysical Events | Amazing Science | Scoop.it

Much attention has been given in the literature to the effects of astrophysical events on human and land-based life. However, little has been discussed on the resilience of life itself. A group of scientists now speculates about the statistics of events that completely sterilize an Earth-like planet with planet radii in the range 0.5–1.5R and temperatures of 300 K, eradicating all forms of life. They consider the relative likelihood of complete global sterilization events from three astrophysical sources – supernovae, gamma-ray bursts, large asteroid impacts, and passing-by stars. To assess such probabilities the researchers consider what cataclysmic event could lead to the annihilation of not just human life, but also extremophiles, through the boiling of all water in Earth’s oceans. Surprisingly, they find that although human life is somewhat fragile to nearby events, the resilience of Ecdysozoa such as Milnesium tardigradum renders global sterilization an unlikely event.

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Astronomers Detect Orbital Motion in Pair of Supermassive Black Holes

Astronomers Detect Orbital Motion in Pair of Supermassive Black Holes | Amazing Science | Scoop.it
VLBA images detect orbital motion of two supermassive black holes as they circle each other at the center of a distant galaxy.

 

Using the supersharp radio "vision" of the National Science Foundation's Very Long Baseline Array (VLBA), astronomers have made the first detection of orbital motion in a pair of supermassive black holes in a galaxy some 750 million light-years from Earth. The two black holes, with a combined mass 15 billion times that of the Sun, are likely separated by only about 24 light-years, extremely close for such a system.

 

"This is the first pair of black holes to be seen as separate objects that are moving with respect to each other, and thus makes this the first black-hole 'visual binary,'" said Greg Taylor, of the University of New Mexico (UNM). Supermassive black holes, with millions or billions of times the mass of the Sun, reside at the cores of most galaxies. The presence of two such monsters at the center of a single galaxy means that the galaxy merged with another some time in the past. In such cases, the two black holes themselves may eventually merge in an event that would produce gravitational waves that ripple across the universe.

 

"We believe that the two supermassive black holes in this galaxy will merge," said Karishma Bansal, a graduate student at UNM, adding that the merger will come at least millions of years in the future. The galaxy, an elliptical galaxy called 0402+379, after its location in the sky, was first observed in 1995. It was studied in 2003 and 2005 with the VLBA. Based on finding two cores in the galaxy, instead of one, Taylor and his collaborators concluded in 2006 that it contained a pair of supermassive black holes.

 

The latest research, which Taylor and his colleagues are reporting in the Astrophysical Journal, incorporates new VLBA observations from 2009 and 2015, along with re-analysis of the earlier VLBA data. This work revealed motion of the two cores, confirming that the two black holes are orbiting each other. The scientists' initial calculations indicate that they complete a single orbit in about 30,000 years.

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ALMA Detects Prebiotic Molecule in Multiple Protostar System

ALMA Detects Prebiotic Molecule in Multiple Protostar System | Amazing Science | Scoop.it

Methyl isocyanate (CH3NCO) is the simplest isocyanate, which along formamide (NH2CHO) contains C, N and O atoms, and could play a key role in the synthesis of amino acid chains known as peptides. Interstellar methyl isocyanate was first detected in Sagittarius B2(N), the hot core of a giant molecular cloud near the Galactic center, in 2015.

 

Now, two international groups of astronomers have detected, for the first time, methyl isocyanate in solar-type protostars, the kind from which our Sun and the Solar System formed. “Our findings indicate that the key ingredients for the origin of life could have been produced at an early stage of the Solar System,” said Dr. David Quénard, from Queen Mary University of London.

 

“This star system seems to keep on giving! Following the discovery of sugars, we’ve now found methyl isocyanate,” said Leiden Observatory astronomer Dr. Niels Ligterink and University College London researcher Dr. Audrey Coutens. “This family of organic molecules is involved in the synthesis of peptides and amino acids, which, in the form of proteins, are the biological basis for life as we know it.”

 

IRAS 16293-2422 is located in a large star-forming region called Rho Ophiuchiin the constellation of Ophiuchus, at a distance of 391 light-years from Earth. The system is composed of two infant stars, IRAS 16293-2422A and IRAS 16293-2422B, whose masses are about 0.5 solar masses. The new results from ALMA show that methyl isocyanate gas surrounds each of these stars.

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Comet claim for mysterious Wow! signal sparks controversy

Comet claim for mysterious Wow! signal sparks controversy | Amazing Science | Scoop.it

The saga of the Wow! signal dates back to 1977, when a SETI (Search for Extraterrestrial Intelligence) survey being conducted at the Big Ear radio telescope at Ohio State University Radio Observatory detected a powerful but unexplained burst of radio waves coming from the general direction of the constellation Sagittarius. The signal was at 1420MHz, which is the frequency of the 21cm wavelength radio waves emitted by neutral hydrogen in space. So the logic goes, any intelligent life out there transmitting signals for us to hear would know that our astronomers will be studying galactic hydrogen at 21cm and therefore be guaranteed to detect their signal. Hence, the Big Ear’s survey was conducted at 1420MHz/21cm.

 

The print-out from the Big Ear telescope that shows the Wow! signal. The numbers and letters refer to the intensity of the radio signal. Intensities above 9 are given by a letter. The signal reached a peak intensity (denoted by ‘U’) that was thirty times stronger than the background noise. Astronomer Jerry Ehman scribbled ‘Wow!’ in the margin upon seeing the signal and the name and the signal entered folklore.

 

Now Antonio Paris of St Petersburg College in Florida and the Center for Planetary Science, which is a non-profit research organization based in the United States, has published new results which he argues proves that the Wow! signal was actually produced by a comet that was in the vicinity at the time. Paris followed up on this comet, 266/P Christensen, and performed radio observations with a dedicated 10 meter radio telescope to test his theory. Writing in the Journal of the Washington Academy of Sciences, he confirms that his experiment did indeed detect a signal of 1420MHz from the comet.

 

However, not everyone is convinced. Alan Fitzsimmons, an astronomer at Queens University Belfast who specializes in studying comets, dismisses Paris’ conclusion as “rubbish.” Aside from the fact that 1420MHz emission has never been detected from a comet before, Fitzsimmons points out that 266/P Christensen is a fairly quiet comet even at perihelion (its closest point to the Sun, which in Christensen’s case is over twice as far from the Sun as Earth, or 2.3 astronomical units).

 

“Paris has targeted a comet that has little activity when at perihelion,” Fitzsimmons tells Astronomy Now. “When he observed the comet it was over four astronomical units from the Sun, which means it would have been effectively inactive. There would have been no hydrogen coma to detect and therefore he could not have seen the comet.”

 

Seth Shostak, who is the Senior Astronomer at the SETI Institute in California, agrees with Fitzsimmons. “I don’t know of any detection of the 21cm line of neutral hydrogen from a comet, and as I used to study galaxies in the neutral hydrogen line, I probably would have heard of that,” he says.

 

Paris is not troubled by this. “Astronomers have not detected hydrogen emission from comets because there has not been much research specifically on this subject,” he says. “While there has been a handful of studies, I suspect we are the first to build a ten-metre telescope to specifically look at this type of Solar System body.”

 

Another problem with the comet theory is that on 15 August 1977, the day that the Wow! signal was detected, the comet was in the wrong place. Bob Dixon, who was Director of the Ohio State University Radio Observatory at the time the Wow! signal was detected, points out that 266/P Christensen’s location was RA 18h 32m 15s, Declination –27º 22’, whereas the Wow! signal was either located at RA 19h 25m 31s, Declination –26º 57’, or RA 19h 28m 22s. Either way, 266/P Christensen would have been visible to the Big Ear 55 minutes earlier instead.

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Probing the possibility of alien life on 'super-Earths'

Probing the possibility of alien life on 'super-Earths' | Amazing Science | Scoop.it

Along with its aesthetic function of helping create the glorious Aurora Borealis, or Northern Lights, the powerful magnetic field surrounding our planet has a fairly important practical value as well: It makes life possible.

 

By deflecting harmful charged particles from the sun and the cosmic rays that constantly bombard the planet, and preventing the solar wind from eroding the atmosphere, Earth's magnetic field has allowed multi-cellular life forms up to and including humans to develop and survive.

 

And now, with the discovery of thousands of planets beyond the solar system known as exoplanets, scientists are eager to learn if rocky "super-Earths," up to 10 times more massive than Earth, might also be able to harbor life.

 

"Finding habitable exoplanets is one of the top three goals of the planetary science and astronomy communities," said Lawrence Livermore National Laboratory physicist Rick Kraus. "With these discoveries come many questions: What do these planets look like? Is our solar system unique? Is Earth unique? Or more specifically, is Earth uniquely habitable?"

 

Those questions have inspired a current National Ignition Facility (NIF) Discovery Science campaign aimed at determining if giant rocky planets could have Earth-like magnetic fields. An atmosphere, mild climate and liquid water are usually considered the bare essentials for life as we know it to evolve, but the presence of a magnetic field is equally important, Kraus said.

 

"Active plate tectonics and a magnetosphere are both considered requirements for a habitable exoplanet," he said. "A stable surface environment free of ionizing radiation is one of the most important qualities of a planet that are considered a requirement for habitability."

 

Earth's magnetic field is generated as convection currents in the planet's liquid iron outer core are twisted by the planet's spin, creating a magneto-dynamo that produces the magnetosphere (dynamos convert mechanical energy into electric energy or in this case, magnetism). A planet with only a solid core may not have a magnetic field, and thus be unlikely to harbor life as we know it.

 

"We need to understand the melting transition of the iron cores in order to determine if it is even possible to have a liquid outer core and a solid inner core within a super-Earth," Kraus said.

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A day lasting 80,000 Earth years? Possible on a strange exoplanet!

A day lasting 80,000 Earth years? Possible on a strange exoplanet! | Amazing Science | Scoop.it

So it’s a good moment to note how good we have it here on Earth. There are longer days in our solar system, but none are quite so pleasant. If “day” refers to the time it takes for a planet to rotate exactly once on its axis (a sidereal day), then the Venusian day is the longest, lasting two hundred and forty-three Earth days. That’s even longer, by nineteen Earth days, than a Venusian year, which is the time it takes the planet to orbit the sun. If, instead, “day” refers to the period between sunrise and sunset (a solar day), Neptune’s is the longest: the gas giant orbits the sun on its side, such that one pole or the other receives daylight for forty-two years non-stop.

 

Farther out in the universe, the days are longer still. Since 1995, some thirty-five hundred extrasolar planets have been discovered, but scientists only gained the ability to measure their spin rates in 2014. A great many of the known ones, though, orbit very close to their host stars and are probably tidally locked, with one side of the planet perpetually facing the star, just as our moon always presents the same face to Earth. “This leads to an infinitely long day, since if you are on the night side, you will never see the sun,” Konstantin Batygin, an astrophysicist at Caltech, explains. Last January, Batygin and the astronomer Mike Brown, also at Caltech, announced the possible existence of a ninth planet in the solar system, a relictual ice giant so distant that it orbits our sun once every twelve thousand to twenty thousand years. Last August, scientists discovered Proxima b, an exoplanet just 4.3 light-years away, which is about as close to us as any extrasolar planet will ever come. It, too, is probably tidally locked, its day eternal. But, even being so near, Proxima b would take us eighty thousand years (some thirty million days) to reach—a very long day’s journey into day.

 

Summer is a separate matter. A planet’s seasons are shaped by two factors: the eccentricity of its orbit—whether it’s closer to the sun at some times of the year than at others—and the tilt of its axis. Earth’s orbit is essentially circular, so the effect on our climate is negligible. But the planet itself leans twenty-three degrees to the side; as we orbit, there comes a day when the North Pole is maximally tilted toward the sun and the Northern Hemisphere sees more daylight than it will all year. That’s today, the summer solstice. (Below the equator, it’s the winter solstice, of course, and in six months our situations will reverse.) If we weren’t off-kilter, we’d have no summer nor any seasons at all. Every day would be as long as every other, and changes in the weather would be driven more by the local geography—latitude, elevation, that mountain range to the west that keeps the rain from falling—than by shifts in the jet stream, or the massive blooms of Pacific plankton in the winter that fuel El Niño, or the decline in sunlight that triggers autumn leaves to change color. Mercury, Venus, and Jupiter, standing all but upright, are seasonless. Sad.

 

Perhaps the weirdest summer of all unfolds on HD 131399Ab, an extrasolar gas giant that was discovered last July by Daniel Apai, an astronomer at the University of Arizona, and his colleagues. The planet belongs to a system with three stars but orbits only one of them, the biggest, which is eighty per cent larger than our sun. The other two stars orbit each other and, together, like a spinning dumbbell, orbit the big one. The view from HD 131399Ab would be spectacular if not for the ferocious winds, the lack of solid ground, and a steady rain of liquid iron. For much of the year, which lasts five hundred and fifty Earth years, the three stars appear close together in the sky, giving the planet “a familiar night side and day side, with a unique triple sunset and sunrise each day,” Kevin Wagner, one of the discoverers, remarked at the time. But as HD 131399Ab progresses in its orbit and the stars drift apart, a day arrives when the setting of one coincides with the rising of the other, and a period of near-constant daylight begins—a solstice of sorts, the start of a summer that will last about a hundred and forty Earth years.

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NASA - Earth-Size Planets: The Newest and Weirdest Generation

NASA - Earth-Size Planets: The Newest and Weirdest Generation | Amazing Science | Scoop.it

A bumper crop of Earth-size planets huddled around an ultra-cool, red dwarf star could be little more than chunks of rock blasted by radiation, or cloud-covered worlds as broiling hot as Venus.

 

Or they could harbor exotic lifeforms, thriving under skies of ruddy twilight.

 

Scientists are pondering the possibilities after this week’s announcement: the discovery of seven worlds orbiting a small, cool star some 40 light-years away, all of them in the ballpark of our home planet in terms of their heft (mass) and size (diameter). Three of the planets reside in the “habitable zone” around their star, TRAPPIST-1, where calculations suggest that conditions might be right for liquid water to exist on their surfaces—though follow-up observations are needed to be sure.

 

All seven are early ambassadors of a new generation of planet-hunting targets.

 

Red dwarf stars -- also called “M-dwarfs” -- outnumber others, including yellow stars like our sun, by a factor of three to one, comprising nearly 75 percent of the stars in our galaxy. They also last far longer. And their planets are proportionally larger compared to the small stars they orbit. That means small, rocky worlds orbiting the nearest red dwarfs will be primary targets for new, powerful telescopes coming online in the years ahead, both in space and on the ground.

 

“The majority of stars are M-dwarfs, which are faint and small and not very luminous,” said Martin Still, program scientist at NASA headquarters in Washington. “So the majority of places where you would look for planets are around these cool, small stars. We are interested in the nearest stars, and the nearest stars are mostly M-dwarfs.”

 

But these are sure to be perplexing planets, with strange properties that must be teased out by careful observation as well as computer simulations. Finding out whether they can support some form of life, and what kind, likely will keep astrobiologists working overtime, perhaps attempting to recreate in the laboratory some of the conditions on these red-tinged worlds.

 

“We’re definitely all working overtime now,” said Nancy Kiang, an astrobiologist at NASA’s Goddard Institute for Space Studies in New York City.

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Hubble dates black hole’s last big meal to between 6 - 9 million years ago

Hubble dates black hole’s last big meal to between 6 - 9 million years ago | Amazing Science | Scoop.it

For the supermassive black hole at the center of our Milky Way galaxy, it’s been a long time between dinners. NASA’s Hubble Space Telescope has found that the black hole ate its last big meal about 6 million years ago, when it consumed a large clump of infalling gas. After the meal, the engorged black hole burped out a colossal bubble of gas weighing the equivalent of millions of Suns, which now billows above and below our galaxy’s center.

 

The immense structures, dubbed the Fermi Bubbles, were first discovered in 2010 by NASA’s Fermi Gamma-ray Space Telescope. But recent Hubble observations of the northern bubble have helped astronomers determine a more accurate age for the bubbles and how they came to be.

 

“For the first time, we have traced the motion of cool gas throughout one of the bubbles, which allowed us to map the velocity of the gas and calculate when the bubbles formed,” said lead researcher Rongmon Bordoloi of the Massachusetts Institute of Technology in Cambridge. “What we find is that a very strong, energetic event happened 6 million to 9 million years ago. It may have been a cloud of gas flowing into the black hole, which fired off jets of matter, forming the twin lobes of hot gas seen in X-ray and gamma-ray observations. Ever since then, the black hole has just been eating snacks.”

 

The new study is a follow-on to previous Hubble observations that placed the age of the bubbles at 2 million years old. A black hole is a dense, compact region of space with a gravitational field so intense that neither matter nor light can escape. The supermassive black hole at the center of our galaxy has compressed the mass of 4.5 million Sun-like stars into a very small region of space.

 

Material that gets too close to a black hole is caught in its powerful gravity and swirls around the compact powerhouse until it eventually falls in. Some of the matter, however, gets so hot it escapes along the black hole’s spin axis, creating an outflow that extends far above and below the plane of a galaxy.

 

The team’s conclusions are based on observations by Hubble’s Cosmic Origins Spectrograph (COS), which analyzed ultraviolet light from 47 distant quasars. Quasars are bright cores of distant active galaxies. Imprinted on the quasars’ light as it passes through the Milky Way bubble is information about the speed, composition, and temperature of the gas inside the expanding bubble.

 

The COS observations measured the temperature of the gas in the bubble at approximately 17,700 degrees Fahrenheit. Even at those sizzling temperatures, this gas is much cooler than most of the super-hot gas in the outflow, which is 18 million degrees Fahrenheit, seen in gamma rays. The cooler gas seen by COS could be interstellar gas from our galaxy’s disk that is being swept up and entrained into the super-hot outflow. COS also identified silicon and carbon as two of the elements being swept up in the gaseous cloud. These common elements are found in most galaxies and represent the fossil remnants of stellar evolution.

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Hubble Detects Exoplanet with Glowing Water Atmosphere

Hubble Detects Exoplanet with Glowing Water Atmosphere | Amazing Science | Scoop.it

The strongest evidence to date for an exoplanet stratosphere has been identified by scientists using NASA's Hubble Space Telescope. Spectra of WASP-121b's atmosphere are the first to show the resolved signature of hot-water molecules for a planet outside the solar system.

 

A planet's stratosphere is a layer of atmosphere where temperatures increase with altitude. For example, Earth's stratosphere contains ozone gas that traps ultraviolet radiation from the Sun, raising the temperature within the layer. Meanwhile, on Jupiter and Saturn's moon, Titan, methane is behind the temperature increase.

 

WASP-121b is a "hot Jupiter" – a gas giant with 1.2 times the mass of Jupiter and 1.9 times the radius and a much higher temperature. Located about 900 light-years away, it orbits the star WASP-121 in just 1.3 days, and the planet's close proximity to the star means the top of its atmosphere reaches 2500 °C – so hot that some metals can boil.

 

While previous research has found possible signs of stratospheres on other exoplanets, the evidence of water on WASP-121b is the best to date. Thomas Evans from the University of Exeter in the UK and colleagues identified the water because it has a very distinct and predictable interaction with light, depending on its temperature. If there is cool water at the top of the atmosphere, the molecules will prevent certain wavelengths of light (typically infrared due to heating) from escaping the planet. On the other hand, if the water is hot, the molecules will "glow" at the same infrared wavelength. "When we pointed Hubble at WASP-121b," says Evans, "we saw glowing water molecules, implying that the planet has a strong stratosphere."

 

The temperature change within stratospheres of solar-system planets is typically around 56 °C, but on WASP-121b the temperature rises by 560 °C. The researchers do not know what chemicals are causing this rise in temperature, but possible candidates include vanadium oxide and titanium oxide because they are gaseous under such high temperatures and are commonly seen in brown-dwarf stars, which have similarities to some exoplanets.

 

"This result is exciting because it shows that a common trait of most of the atmospheres in our solar system – a warm stratosphere – also can be found in exoplanet atmospheres," says team member Mark Marley at NASA's Ames Research Center in the US. "We can now compare processes in exoplanet atmospheres with the same processes that happen under different sets of conditions in our own solar system."

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Cold Cosmic Mystery Solved

Cold Cosmic Mystery Solved | Amazing Science | Scoop.it

In 2004, astronomers examining a map of the radiation leftover from the Big Bang (the cosmic microwave background, or CMB) discovered the Cold Spot, a larger-than-expected unusually cold area of the sky. The physics surrounding the Big Bang theory predicts warmer and cooler spots of various sizes in the infant universe, but a spot this large and this cold was unexpected.

 

Now, a team of astronomers led by Dr. István Szapudi of the Institute for Astronomy at the University of Hawaii at Manoa may have found an explanation for the existence of the Cold Spot, which Szapudi says may be “the largest individual structure ever identified by humanity.”

 

Using data from Hawaii’s Pan-STARRS1 (PS1) telescope located on Haleakala, Maui, and NASA’s Wide Field Survey Explorer (WISE) satellite, Szapudi’s team discovered a large supervoid, a vast region 1.8 billion light-years across, in which the density of galaxies is much lower than usual in the known universe. This void was found by combining observations taken by PS1 at optical wavelengths with observations taken by WISE at infrared wavelengths to estimate the distance to and position of each galaxy in that part of the sky.

 

Earlier studies, also done in Hawaii, observed a much smaller area in the direction of the Cold Spot, but they could establish only that no very distant structure is in that part of the sky. Paradoxically, identifying nearby large structures is harder than finding distant ones, since we must map larger portions of the sky to see the closer structures.

 

The large three-dimensional sky maps created from PS1 and WISE by Dr. András Kovács (Eötvös Loránd University, Budapest, Hungary) were thus essential for this study. The supervoid is only about 3 billion light-years away from us, a relatively short distance in the cosmic scheme of things.

 

Imagine there is a huge void with very little matter between you (the observer) and the CMB. Now think of the void as a hill. As the light enters the void, it must climb this hill. If the universe were not undergoing accelerating expansion, then the void would not evolve significantly, and light would descend the hill and regain the energy it lost as it exits the void. But with the accelerating expansion, the hill is measurably stretched as the light is traveling over it. By the time the light descends the hill, the hill has gotten flatter than when the light entered, so the light cannot pick up all the energy it lost upon entering the void. The light exits the void with less energy, and therefore at a longer wavelength, which corresponds to a colder temperature.

 

Getting through a supervoid can take millions of years, even at the speed of light, so this measurable effect, known as the Integrated Sachs-Wolfe (ISW) effect, might provide the first explanation one of the most significant anomalies found to date in the CMB, first by a NASA satellite called the Wilkinson Microwave Anisotropy Probe (WMAP), and more recently, by Planck, a satellite launched by the European Space Agency.

 

While the existence of the supervoid and its expected effect on the CMB do not fully explain the Cold Spot, it is very unlikely that the supervoid and the Cold Spot at the same location are a coincidence. The team will continue its work using improved data from PS1 and from the Dark Energy Survey being conducted with a telescope in Chile to study the Cold Spot and supervoid, as well as another large void located near the constellation Draco.

 

The study is published online in Monthly Notices of the Royal Astronomical Society by the Oxford University Press.

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Flooded ExoEarth: Most habitable planets may be completely covered in water

Flooded ExoEarth: Most habitable planets may be completely covered in water | Amazing Science | Scoop.it

When you imagine what a rocky, habitable planet looks like, it's easy to picture an alternate Earth where land and oceans exist in an ideal balance.

 

When you imagine what a rocky, habitable planet looks like, it's easy to picture an alternate Earth where land and oceans exist in an ideal balance. Unfortunately, that's not necessarily how it will pan out in real life... in fact, you might be surprised if there's land at all. University of Barcelona researcher Fergus Simpson has published a study suggesting that most planets with any significant amount of water are likely to be completely (or almost completely) submerged in it. He ran computer simulations accounting for numerous factors in a planet (such as the deep water cycle and erosion), and most with substantial water levels had an above-water land mass of less than 10 percent -- well below Earth's 29 percent.

 

Those planets that had less water tended to have much less, to the point where deserts dominated the landscape. Also, size plays a role. Larger habitable planets (including Earth) are more likely to be water worlds thanks to deeper oceans and stronger gravity, according to the calculations, while smaller ones are drier.

 

If reasonably accurate, the data points to Earth hitting a rare sweet spot, possibly due to unusually deep water basins. And that makes sense at first glance. Despite what Earth looks like, water only occupies a tiny amount of volume compared to the rest of the planet. It wouldn't take much more to inundate the land, or much less to make it barren. You can see for yourself in the video below.

 

There is reason to be skeptical. Astrophysicist Sean Raymond warns that there are still a number of unknowns that may play an important role in water levels, and recent models suggest that water delivery to planets is relatively "reliable" with fewer surges or shortfalls. However, Simpson is quick to add that his theory should be testable soon. Future instruments (likely including the James Webb Space Telescope) will have enough power to measure the atmospheric compositions of alien planets, giving a clue as to how much water there is on the surface. If nothing else, the study is a reminder that we shouldn't assume a planet is human-friendly just because there's plenty of H2O.

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Reaching for the Stars: Breakthrough Sends Smallest-Ever Satellites into Orbit

Reaching for the Stars: Breakthrough Sends Smallest-Ever Satellites into Orbit | Amazing Science | Scoop.it

Despite still unsolved technical glitches and regulatory hurdles, nanosatellite swarms could someday be the cornerstone for revolutionary interplanetary or even interstellar space-science missions, experts believe.

 

Breakthrough Starshot, the $100 million initiative aiming to send robotic missions to nearby stars by the mid-21st century, has achieved what might prove to be a “Sputnik moment” in successfully lofting its first spacecraft—the smallest ever launched and operated in orbit.

 

In 1957 the Soviet Union shocked the world by flying the first artificial satellite, Sputnik 1, an 83-kilogram metallic orb about twice the size of a basketball that broadcast a radio message to anyone listening down on Earth. On June 23, Breakthrough Starshot sent not one but six satellites into low-Earth orbit, riding as supplementary payloads on an Indian rocket launching two other educational satellites built by the European space company OHB System AG. These six satellites are comparatively dainty, but punch far above their weight. Called “Sprites,” each is a 4-gram flake of circuit-board just 3.5 centimeters on a side, packing solar panels, computers, sensors and communications equipment into an area equal to a U.S. postage stamp. Representatives of Breakthrough Starshot, which is funded by the Russian billionaire Yuri Milner, brokered the deal that sent the Sprites piggybacking to orbit. They also worked with the U.S. State Department to ensure the project did not violate strict federal regulations limiting exports of spaceflight hardware.

 

Manufactured in bulk, low-cost Sprites could be deployed and networked by the hundreds or thousands to create space-based sensor arrays of unprecedented breadth, with each craft so lightweight that it could operate without propellant, shifting or maintaining its orbit solely through the radiation pressure of starlight or the forces imparted by a planet’s magnetic field. More wildly, future iterations of Sprites could become Breakthrough’s hoped-for “StarChips”—spacecraft integrated with gossamer-thin, meter-wide “lightsails” that would travel at 20 percent the speed of light to Alpha Centauri or other nearby stars, propelled by high-powered pulses of photons from a gargantuan ground-based laser array. Progress toward this starry-eyed goal is slow but steady, Breakthrough representatives say, and the organization is set to solicit research proposals for the associated “grand challenges” in optics, communications, materials science and other disciplines later this year.

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Possible first sighting of an exomoon

Possible first sighting of an exomoon | Amazing Science | Scoop.it

Phys.org reports that the team lead by Dr. David Kipping, assistant professor of astronomy at Columbia University, has spotted what might be the first evidence of a moon orbiting an exoplanet. By harnessing data from the Hubble Space Telescope, researchers have identified an exomoon candidate, called Kepler-1625b.

 

“It would be a pretty big deal if this exomoon candidate turns out to be real, because it would be the first of its kind, and moons stand to tell us quite a bit about our solar system and other star systems,” Alex Teachey, a National Science Foundation graduate research fellow at Columbia University, who participated in the research, told Fox News via email. "This could provide vital clues about how star systems form and evolve, he added.

 

Kepler-1625b, which is orbiting the star Kepler-1625, is approximately 4,000 light years away, according to the report.

 

The BBC reports that the exomoon may have the size and mass of Neptune, and is circling a planet about the size of Jupiter, but with 10 times the mass. “It it turns out to be, as we've suspected, a massive Jupiter-like planet with a moon roughly the size of Neptune, it's very strange, and not like anything astronomers have expected to exist out there,” Teachey explains. “And that might tell you there's really some strange stuff going on elsewhere, not at all like what we see in our neighborhood.”

 

Teachey adds that scientists need to do a lot more research on the possible exomoon. “Of course, its strangeness is reason enough to pause and say, 'is this for real?' and believe me, we've asked ourselves that quite a bit,” he said. “And so we just want to be as clear as possible that, while we think this candidate is worthy of follow-up with Hubble, there's still a chance we end up seeing nothing when we observe it in October. We'll just have to wait and see.”

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Surprise methanol detection in Enceladus’s plumes

Surprise methanol detection in Enceladus’s plumes | Amazing Science | Scoop.it

A serendipitous detection of the organic molecule methanol around an intriguing moon of Saturn suggests that material spewed from Enceladus undertakes a complex chemical journey once vented into space. This is the first time that a molecule from Enceladus has been detected with a ground-based telescope. Dr Emily Drabek-Maunder, of Cardiff University, will present the results on Tuesday 4th July at the National Astronomy Meeting at the University of Hull.

 

Enceladus's plumes are thought to originate in water escaping from a subsurface ocean through cracks in the moon's icy surface. Eventually these plumes feed into Saturn's second-outermost ring, the E-ring. Drabek-Maunder says: "Recent discoveries that icy moons in our outer Solar System could host oceans of liquid water and ingredients for life have sparked exciting possibilities for their habitability. But in this case, our findings suggest that that methanol is being created by further chemical reactions once the plume is ejected into space, making it unlikely it is an indication for life on Enceladus."

 

Past studies of Enceladus have involved the NASA/ESA Cassini spacecraft, which has detected molecules like methanol by directly flying into the plumes. Recent work has found similar amounts of methanol in Earth's oceans and Enceladus's plumes.

 

In this study, Dr Jane Greaves of Cardiff University and Dr Helen Fraser of the Open University detected the bright methanol signature using the IRAM 30-metre radio telescope in the Spanish Sierra Nevada. "This observation was very surprising since it was not the main molecule we were originally looking for in Enceladus's plumes," says Greaves.

 

The team suggests the unexpectedly large quantity of methanol may have two possible origins: either a cloud of gas expelled from Enceladus has been trapped by Saturn's magnetic field, or gas has spread further out into Saturn's E-ring. In either case, the methanol has been greatly enhanced compared to detections in the plumes. Team member Dr Dave Clements of Imperial College, points out: "Observations aren't always straightforward. To interpret our results, we needed the wealth of information Cassini gave us about Enceladus's environment. This study suggests a degree of caution needs to be taken when reporting on the presence of molecules that could be interpreted as evidence for life."

 

Cassini will end its journey later this year, leaving remote observations through ground- and space-based telescopes as the only possibility for exploring Saturn and its moons -- at least for now. Drabek-Maunder adds: "This finding shows that detections of molecules at Enceladus are possible using ground-based facilities. However, to understand the complex chemistry in these subsurface oceans, we will need further direct observations by future spacecraft flying through Enceladus's plumes."

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Milky Way could harbor 100 billion brown dwarfs

Milky Way could harbor 100 billion brown dwarfs | Amazing Science | Scoop.it

Our galaxy could have 100 billion brown dwarfs or more, according to work by an international team of astronomers, led by Koraljka Muzic from the University of Lisbon and Aleks Scholz from the University of St Andrews. On Thursday 6 July Scholz will present their survey of dense star clusters, where brown dwarfs are abundant, at the National Astronomy Meeting at the University of Hull.

 

Brown dwarfs are objects intermediate in mass between stars and planets, with masses too low to sustain stable hydrogen fusion in their core, the hallmark of stars like the Sun. After the initial discovery of brown dwarfs in 1995, scientists quickly realised that they are a natural by-product of processes that primarily lead to the formation of stars and planets.

 

All of the thousands of brown dwarfs found so far are relatively close to the Sun, the overwhelming majority within 1500 light years, simply because these objects are faint and therefore difficult to observe. Most of those detected are located in nearby star forming regions, which are all fairly small and have a low density of stars.

 

In 2006 the team began a new search for brown dwarfs, observing five nearby star forming regions. The Substellar Objects in Nearby Young Clusters (SONYC) survey included the star cluster NGC 1333, 1000 light years away in the constellation of Perseus. That object had about half as many brown dwarfs as stars, a higher proportion than seen before.

 

To establish whether NGC 1333 was unusual, in 2016 the team turned to another more distant star cluster,RCW 38, in the constellation of Vela. This has a high density of more massive stars, and very different conditions to other clusters.

 

RCW 38 is 5500 light years away, meaning that the brown dwarfs are both faint, and hard to pick out next to the brighter stars. To get a clear image, Scholz, Muzic and their collaborators used the NACO adaptive optics camera on the European Southern Observatory's Very Large Telescope, observing the cluster for a total of almost 3 hours, and combining this with earlier work.

 

The researchers found just as many brown dwarfs in RCW 38 – about half as many as there are stars- and realised that the environment where the stars form, whether stars are more or less massive, tightly packed or less crowded, has only a small effect on how brown dwarfs form.

 

Scholz says: "We've found a lot of brown dwarfs in these clusters. And whatever the cluster type, the brown dwarfs are really common. Brown dwarfs form alongside stars in clusters, so our work suggests there are a huge number of brown dwarfs out there."

 

From the SONYC survey, Scholz and team leader Koraljka Muzic, estimate that our galaxy, the Milky Way, has a minimum of between 25 and 100 billion brown dwarfs. There are many smaller, fainter brown dwarfs too, so this could be a significant underestimate, and the survey confirms these dim objects are ubiquitous.

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NASA Completes Study of Potential Future Mission to Uranus and Neptune

NASA Completes Study of Potential Future Mission to Uranus and Neptune | Amazing Science | Scoop.it

Uranus and Neptune are known as ‘ice giants.’ In spite of this name, relatively little solid ice is thought to be in them today, but it is believed there is a massive liquid ocean beneath their clouds. This makes them fundamentally different from Solar System’s terrestrial planets and gas giants.

 

To date, Uranus and Neptune have been visited briefly by one spacecraft,NASA’s Voyager 2: it rapidly flew by Uranus in 1986 and Neptune in 1989, as part of its grand tour of discovery that previously took it by Jupiter and Saturn.

 

“Exploration of at least one ‘ice giant’ system is critical to advance our understanding of the Solar System, exoplanetary systems, and to advance our understanding of planetary formation and evolution,” the study authors said. “Three key points highlight the importance of sending a mission to Uranus and Neptune.”

 

“First, they represent a class of planet that is not well understood, and which is fundamentally different from the gas giants (Jupiter and Saturn) and the terrestrial planets. Ice giants are, by mass, about 65% water and other so-called ‘ices,’ such as methane and ammonia. In spite of the ‘ice’ name, these species are thought to exist primarily in a massive, super-critical liquid water ocean. No current model for their interior structure is consistent with all observations.”

 

“A second key factor in their importance is that ice giants are extremely common in our Galaxy. They are much more abundant than gas giants such as Jupiter, and the majority of planets discovered so far appear to be ice giants. Exploration of our local ice giants would allow us to better characterize exoplanets.”

 

“The final point to emphasize about ‘ice giants’ is that they challenge our understanding of planetary formation, evolution and physics.”

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New evidence that all stars are born in pairs

New evidence that all stars are born in pairs | Amazing Science | Scoop.it

Did our sun have a twin when it was born 4.5 billion years ago?

Almost certainly yes - though not an identical twin. And so did every other sunlike star in the universe, according to a new analysis by a theoretical physicist from UC Berkeley and a radio astronomer from the Smithsonian Astrophysical Observatory at Harvard University.

 

Many stars have companions, including our nearest neighbor, Alpha Centauri, a triplet system. Astronomers have long sought an explanation. Are binary and triplet star systems born that way? Did one star capture another? Do binary stars sometimes split up and become single stars?

 

Astronomers have even searched for a companion to our sun, a star dubbed Nemesis because it was supposed to have kicked an asteroid into Earth's orbit that collided with our planet and exterminated the dinosaurs. It has never been found.

 

The new assertion is based on a radio survey of a giant molecular cloud filled with recently formed stars in the constellation Perseus, and a mathematical model that can explain the Perseus observations only if all sunlike stars are born with a companion.

"We are saying, yes, there probably was a Nemesis, a long time ago," said co-author Steven Stahler, a UC Berkeley research astronomer.

 

"We ran a series of statistical models to see if we could account for the relative populations of young single stars and binaries of all separations in the Perseus molecular cloud, and the only model that could reproduce the data was one in which all stars form initially as wide binaries. These systems then either shrink or break apart within a million years."

 

In this study, "wide" means that the two stars are separated by more than 500 astronomical units, or AU, where one astronomical unit is the average distance between the sun and Earth (93 million miles). A wide binary companion to our sun would have been 17 times farther from the sun than its most distant planet today, Neptune.

 

Based on this model, the sun's sibling most likely escaped and mixed with all the other stars in our region of the Milky Way galaxy, never to be seen again. "The idea that many stars form with a companion has been suggested before, but the question is: how many?" said first author Sarah Sadavoy, a NASA Hubble fellow at the Smithsonian Astrophysical Observatory. "Based on our simple model, we say that nearly all stars form with a companion. The Perseus cloud is generally considered a typical low-mass star-forming region, but our model needs to be checked in other clouds."

 

The idea that all stars are born in a litter has implications beyond star formation, including the very origins of galaxies, Stahler said.

Stahler and Sadavoy posted their findings in April on the arXiv server. Their paper has been accepted for publication in the Monthly Notices of the Royal Astronomical Society.

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Final Kepler Report Includes 219 New Potential Exoplanets

Final Kepler Report Includes 219 New Potential Exoplanets | Amazing Science | Scoop.it

Earth is the only planet we know of right now that supports life, but considering the scale of the universe it seems like there could be others. The first step in finding these Earth-like worlds is to detect planets orbiting nearby stars. That’s what NASA’s Kepler space telescope has been doing these past eight years. The project has had its ups and downs, but the final planetary catalog unveiled by astronomers during a recent meeting at the Ames Research Center signifies the final chapter of Kepler. Its grand total: 4,034 objects.

 

These exoplanets were detected by Kepler using what’s known as the transit method. The telescope watches a patch of the sky, recording dips in luminance that could indicate a planet passing between its host star and us. By monitoring over time, astronomers can determine the size, mass, and orbit of such a planet. This requires the distant solar system to be at just the right angle, and Kepler can only see a small segment of the sky. Still, we knew of only 300 probably exoplanets when Kepler launched. Now, there are thousands.

 

However, the Kepler satellite hit a snag four years ago when two of its four reaction wheels failed, leaving it unable to maintain orientation. The mission seemed doomed, but NASA worked out a clever solution in 2013 using the solar wind to stabilize the spacecraft in certain parts of its orbit. This K2 search program has been underway ever since, and it slated to come to an end on September 30th, 2017.

 

The list includes many objects that are confirmed planets, but everything on the list is at least 90 percent certain to be an exoplanet. To date, more than 1,200 exoplanets have been confirmed using Kepler data. The latest update to Kepler’s survey of the sky includes 219 new planetary candidates. Ten of them are in the habitable zone of their stars, meaning they (or their moons) could support life.

 

Kepler’s discoveries with new planets indicated in yellow on the above graph. One analysis presented alongside the new data sheds light on the way smaller planets form. The most common “small” planets come in two sizes. There are rocky worlds about 1.5-times the diameter of Earth, known as super-Earths. Then, the commonality of planets drops off until you get to “mini-Neptunes” at about two times Earth’s diameter. All planets seem to begin with roughly the same amount of solid material in the core, then gas adheres in large quantities to create a gas giant. Alternatively, a small envelope of gas sticks and you get a planet like Earth.

The data acquired by Kepler will instrumental in the search for life.

 

NASA plans to deploy a satellite in the 2030s that could capture images of these planets. In the meantime, the Webb Space Telescope might be able to image some of these planets with its 6.5-meter mirror. It launches in October 2018.

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