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  • richardmitnick 8:07 am on March 20, 2015 Permalink | Reply
    Tags: , , , Exoplanets   

    From Science 2.0- “ESA’s CHEOPS Satellite: The Pharaoh of Exoplanet Hunting” 

    Science 2.0 bloc

    Science 2.0

    March 19th 2015
    Tomasz Nowakowski

    ESA CHEOPS
    CHEOPS

    Just like the Pharaoh Cheops, who ruled the ancient Old Kingdom of Egypt, ESA’s CHaracterising ExOPlanet Satellite (CHEOPS) could be someday ruling in the field of exoplanet hunting.

    It will be the first mission dedicated to search for transits by means of ultrahigh precision photometry on bright stars already known to host planets. “CHEOPS looks at stars that are already known to host planets and attempts to observe transits. I say attempts because its main targets are planets that have been discovered through Doppler techniques,” Don Pollacco of the University of Warwick, UK spokesperson for the CHEOPS mission, told me.

    Large ground-based high-precision Doppler spectroscopic surveys carried out during the last years have identified hundreds of stars hosting planets in the super-Earth to Neptune mass range and will continue to do so into the foreseeable future. The characteristics of these stars and the knowledge of the planet ephemerids make them ideal targets for precision photometric measurements from space. CHEOPS will be the only facility able to follow-up all these targets for precise radius measurements.

    “Doppler surveys have been going on for some time and have found a significant fraction of multiple and duper earth massed planets, well before Kepler did this.

    NASA Kepler Telescope
    NASA/Kepler

    Some proportions of these are expected to transit their host star – maybe 10%. As you know when these transits are meant to occur you can look at these targets specifically at that time and avoid wasting too much time,” Pollacco said. “10% doesn’t sound much but these will be important targets in that they’ll be bright, already have Doppler curves and hence able to determine their densities. It’s likely that a few tens of planets maybe discovered this way, there’s a handful from Kepler if that.”

    Knowing where to look and at what time to observe, makes CHEOPS the most efficient instrument to search for shallow transits.

    With an accurate knowledge of masses and radii for an unprecedented sample of planets, CHEOPS will set new constraints on the structure and hence on the formation and evolution of planets in this mass range.

    “By knowing where to look and at what time, CHEOPS is the most efficient instrument to detect shallow transits. It will significantly increase the sample of exoplanets for which we know both mass and radius, providing new insights and constraints on formation models,” said Willy Benz from the University of Bern, Switzerland, the Principal Investigator for CHEOPS.

    ESA is the mission architect for CHEOPS, responsible for spacecraft development and launch, and for the interface with the science community during science operations in orbit.

    CHEOPS is the first of the small-size (S class) missions of ESA, and was selected from 26 other proposed missions. These missions are designed to take full advantage of known technologies. They should be low cost and rapidly developed missions, in order to offer greater flexibility in response to new ideas from the scientific community.

    “The need for a pointed space telescope to do high precision transit observations, has been known for a while and there were various concepts already explored. In the UK we had something nicknamed “BEE” which was meant to follow up SuperWASP discoveries. CHEOPS was already under development when the first S mission opportunity arose and so it was in good shape to be submitted to this,” Pollacco revealed. “The S missions were meant to be opportunities for smaller ESA members to demonstrate their space industries and take the lead so CHEOPS was extremely well placed.”

    Pollacco admitted that CHEOPS is different to NASA exoplanet hunting missions like Kepler spacecraft or Transiting Exoplanet Survey Satellite (TESS).

    NASA TESS
    NASA/TESS

    These are survey missions that look at large areas of the sky and discover transiting planets, while CHEOPS looks at stars that are already known to have orbiting planets.

    “For TESS it really remains to be seen what can be achieved but in any case CHEOPS with its superior accuracy will produce more accurate transits, and hence densities of Doppler confirmed TESS planets,” he said. “A second aim for CHEOPS is to follow up transits discovered from other surveys, like the Next-Generation Transit Survey (NGTS), again because of its superior accuracy.”

    The satellite will fly at an altitude of between 650 and 800km, in a dusk-dawn helio-synchronous orbit, and will have a design lifetime of 3.5 years. “For CHEOPS scheduling will be important given its low orbit meaning that it can’t stare long in many directions,” Pollacco added.

    CHEOPS should be able to cover at least 50% of the whole sky for a minimum total duration of 50 days of observation per year and per target. The observation may be interrupted up to 50% (goal would be 20%) of the satellite orbital duration (Earth eclipse, Sun, etc.).

    The Prime contractor for CHEOPS is Airbus Defence and Space, Spain. The spacecraft is based on the Airbus Defence and Space AstroBus family of low cost satellite platforms (following on from e.g. Spot 6&7, KazEOSat-1), and the ninth for an ESA program following on from Sentinel 5 Precursor and the MetOp Second Generation satellites.

    CHEOPS mission will be implemented in partnership with Switzerland, through the Swiss Space Office (SSO), a division of the Swiss State Secretariat for Education, Research and Innovation (SERI). The University of Bern leads the consortium of 11 ESA Member States contributing to the mission and represented in the CHEOPS Science Team.

    The science instrument is led by the University of Bern, with important contributions from Italy, Germany, Austria, and Belgium. Other contributions to the science instrument in the form of hardware, or in the science operations and exploitation, are provided by the United Kingdom, France, Hungary, Portugal and Sweden. The Mission Operations Centre is under the responsibility of Spain, while the Science Operations Centre is located at the University of Geneva, Switzerland.

    “For historical reasons UK industry is not playing a major role in CHEOPS. In the original baseline we expected the UK to run the mission operations but for a number of reasons that never happened,” Pollacco said. “However we retain some software contributions and so some elements of the UK exoplanet community have stayed in touch with the mission. It’s worth noting that Didier Queloz [Swiss astronomer] moved to Cambridge from Geneva over the last couple of years but retains a significant post at Geneva specifically for CHEOPS work. In other countries, e.g. Germany, Italy, there is a far larger involvement, both technically and industrially, although the Swiss remain by far the largest contributor, as it should be.”

    CHEOPS will most likely be launched into space by a Soyuz or Vega launcher from Kourou spaceport in French Guiana in December 2017.

    See the full article here.

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  • richardmitnick 9:31 am on March 18, 2015 Permalink | Reply
    Tags: , , Exoplanets, , Niels Bohr Institute   

    From Niels Bohr Institute: “Planets in the habitable zone around most stars, calculate researchers” 

    Niels Bohr Institute bloc

    Niels Bohr Institute

    18 March 2015
    Gertie Skaarup
    skaarup@nbi.dk

    Habitable planets

    Astronomers have discovered thousands of exoplanets in our galaxy, the Milky Way, using the Kepler satellite and many of them have multiple planets orbiting the host star.

    NASA Kepler Telescope
    NASA/Kepler

    By analysing these planetary systems, researchers from the Australian National University and the Niels Bohr Institute in Copenhagen have calculated the probability for the number of stars in the Milky Way that might have planets in the habitable zone. The calculations show that billions of the stars in the Milky Way will have one to three planets in the habitable zone, where there is the potential for liquid water and where life could exist. The results are published in the scientific journal, Monthly Notices of the Royal Astronomical Society.

    1
    Planets outside our solar system are called exoplanets. The Kepler satellite observes exoplanets by measuring the light curve of a star. When a planet moves in front of the star there is a small dip in brightness. If this little dip in brightness occurs regularly, there might be a planet orbiting the star and obscuring its light.

    Using NASA’s Kepler satellite, astronomers have found about 1,000 planets around stars in the Milky Way and they have also found about 3,000 other potential planets. Many of the stars have planetary systems with 2-6 planets, but the stars could very well have more planets than those observable with the Kepler satellite, which is best suited for finding large planets that orbit relatively close to their stars.

    Planets that orbit close to their stars would be too scorching hot to have life, so to find out if such planetary systems might also have planets in the habitable zone with the potential for liquid water and life, a group of researchers from the Australian National University and the Niels Bohr Institute at the University of Copenhagen made calculations based on a new version of a 250-year-old method called the Titius-Bode law.

    2
    Light curves of the five planets orbiting the star Kepler-62. The dip in the light curve occur when the planet moves in front of the host star, thereby dimming the light of the star. The dip in the light curve is proportional to the size of the planet. The two light curves at the bottom of the plot are of planets in the habitable zone.

    Calculating planetary positions

    The Titius-Bode law was formulated around 1770 and correctly calculated the position of Uranus before it was even discovered. The law states that there is a certain ratio between the orbital periods of planets in a solar system. So the ratio between the orbital period of the first and second planet is the same as the ratio between the second and the third planet and so on. Therefore, if you knew how long it takes for some of the planets to orbit around the Sun/star, you can calculate how long it takes for the other planets to orbit and can thus calculate their position in the planetary system. You can also calculate if a planet is ‘missing’ in the sequence.

    “We decided to use this method to calculate the potential planetary positions in 151 planetary systems, where the Kepler satellite had found between 3 and 6 planets. In 124 of the planetary systems, the Titius-Bode law fit with the position of the planets as good as or better than our own solar system. Using T-B’s law we tried to predict where there could be more planets further out in the planetary systems. But we only made calculations for planets where there is a good chance that you can see them with the Kepler satellite,” explains Steffen Kjær Jacobsen, PhD student in the research group Astrophysics and Planetary Science at the Niels Bohr Institute at the University of Copenhagen.

    In 27 of the 151 planetary systems, the planets that had been observed did not fit the T-B law at first glance. They then tried to place planets into the ‘pattern’ for where planets should be located. Then they added the planets that seemed to be missing between the already known planets and also added one extra planet in the system beyond the outermost known planet. In this way, they predicted a total of 228 planets in the 151 planetary systems.

    2
    The illustration shows the habitable zone for different types of stars. The distance to the habitable zone is dependent on how big and bright the star is. The green area is the habitable zone (HZ), where liquid water can exist on a planet’s surface. The red area is too hot for liquid water on the planetary surface and the blue area is too cold for liquid water on the planetary surface. (Credit: NASA, Kepler)

    “We then made a priority list with 77 planets in 40 planetary systems to focus on because they have a high probability of making a transit, so you can see them with Kepler. We have encouraged other researchers to look for these. If they are found, it is an indication that the theory stands up,” explains Steffen Kjær Jacobsen.

    Planets in the habitable zone

    Planets that orbit very close around a star are too scorching hot to have liquid water and life and planets that are far from the star would be too deep-frozen, but the intermediate habitable zone, where there is the potential for liquid water and life, is not a fixed distance. The habitable zone for a planetary system will be different from star to star, depending on how big and bright the star is.

    The researchers evaluated the number of planets in the habitable zone based on the extra planets that were added to the 151 planetary systems according to the Titius-Bode law. The result was 1-3 planets in the habitable zone for each planetary system.

    4
    Exoplanetary systems where the previously known planets are marked with blue dots, while the red dots show the planets predicted by the Titius-Bode law on the composition of planetary systems. 124 planetary systems in the survey – based on data from the Kepler satellite, fit with this formula.

    Out of the 151 planetary systems, they now made an additional check on 31 planetary systems where they had already found planets in the habitable zone or where only a single extra planet was needed to meet the requirements.

    “In these 31 planetary systems that were close to the habitable zone, our calculations showed that there was an average of two planets in the habitable zone. According to the statistics and the indications we have, a good share of the planets in the habitable zone will be solid planets where there might be liquid water and where life could exist,” explains Steffen Kjær Jacobsen.

    If you then take the calculations further out into space, it would mean that just in our galaxy, the Milky Way, there could be billions of stars with planets in the habitable zone, where there could be liquid water and where life could exist.

    He explains that what they now want to do is encourage other researchers to look at the Kepler data again for the 40 planetary systems that they have predicted should be well placed to be observed with the Kepler satellite.

    Out of the 151 planetary systems, they now made an additional check on 31 planetary systems where they had already found planets in the habitable zone or where only a single extra planet was needed to meet the requirements.

    “In these 31 planetary systems that were close to the habitable zone, our calculations showed that there was an average of two planets in the habitable zone. According to the statistics and the indications we have, a good share of the planets in the habitable zone will be solid planets where there might be liquid water and where life could exist,” explains Steffen Kjær Jacobsen.

    If you then take the calculations further out into space, it would mean that just in our galaxy, the Milky Way, there could be billions of stars with planets in the habitable zone, where there could be liquid water and where life could exist.

    He explains that what they now want to do is encourage other researchers to look at the Kepler data again for the 40 planetary systems that they have predicted should be well placed to be observed with the Kepler satellite.

    Article in Monthly Notices of the Royal Astronomical Society

    See the full article here.

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    Niels Bohr Institute Campus

    The Niels Bohr Institute (Danish: Niels Bohr Institutet) is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics.

    The Institute was founded in 1921, as the Institute for Theoretical Physics of the University of Copenhagen, by the Danish theoretical physicist Niels Bohr, who had been on the staff of the University of Copenhagen since 1914, and who had been lobbying for its creation since his appointment as professor in 1916. On the 80th anniversary of Niels Bohr’s birth – October 7, 1965 – the Institute officially became The Niels Bohr Institute.[1] Much of its original funding came from the charitable foundation of the Carlsberg brewery, and later from the Rockefeller Foundation.[2]

    During the 1920s, and 1930s, the Institute was the center of the developing disciplines of atomic physics and quantum physics. Physicists from across Europe (and sometimes further abroad) often visited the Institute to confer with Bohr on new theories and discoveries. The Copenhagen interpretation of quantum mechanics is named after work done at the Institute during this time.

    On January 1, 1993 the institute was fused with the Astronomic Observatory, the Ørsted Laboratory and the Geophysical Institute. The new resulting institute retained the name Niels Bohr Institute.

     
  • richardmitnick 8:11 am on March 10, 2015 Permalink | Reply
    Tags: , , , Exoplanets   

    From Discovery: “‘Habitable’ Super-Earth Might Exist After All” 

    Discovery News
    Discovery News

    Mar 9, 2015
    Ian O’Neill

    1
    Possible image of Gliese 581d, a controversial exoplanet that may exist only 20 light-years from Earth.

    Despite having discovered nearly 2,000 alien worlds beyond our solar system, the profound search for exoplanets — a quest focused on finding a true Earth analog — is still in its infancy. It is therefore not surprising that some exoplanet discoveries aren’t discoveries at all; they are in fact just noise in astronomical data sets.

    But when disproving the existence of extrasolar planets that have some characteristics similar to Earth, we need to take more care during the analyses of these data, argue astronomers from Queen Mary, University of London and the University of Hertfordshire.

    In a paper published by the journal Science last week, the researchers focus on the first exoplanet discovered to orbit a nearby star within its habitable zone.

    Revealed in 2009, Gliese 581d hit the headlines as a “super-Earth” that had the potential to support liquid water on its possibly rocky surface. With a mass of around 7 times that of Earth, Gliese 581d would be twice as big with a surface gravity around twice that of Earth. Though extreme, it’s not such a stretch of the imagination that such a world, if it is proven to possess an atmosphere and liquid ocean, that life could take hold.

    And the hunt for life-giving alien worlds is, of course, the central motivation for exoplanetary studies.

    But the exoplanet signal has been called into doubt.

    3
    Gliese 581d’s star, Gliese 581, is a small red dwarf around 20 light-years away.
    ESO/Digitized Sky Survey photo.

    Red dwarfs are known to be tempestuous little stars, often generating violent flaring outbursts and peppered in dark features called starspots. To detect the exoplanet, astronomers measured the very slight frequency shift (Doppler shift) of light from the star — as the world orbits, it exerts a tiny gravitational “tug”, causing the star to wobble. When this periodic wobble is detected, through an astronomical technique known as the “radial velocity method,” a planet may be revealed.

    Last year, however, in a publication headed by astronomers at The Pennsylvania State University, astronomers pointed to the star’s activity as an interfering factor that may have imitated the signal from an orbiting planet when in fact, it was just noisy data.

    But this conclusion was premature, argues Guillem Anglada-Escudé, of Queen Mary, saying that “one needs to be more careful with these kind of claims.”

    “The existence, or not, of GJ 581d is significant because it was the first Earth-like planet discovered in the ‘Goldilocks’-zone around another star and it is a benchmark case for the Doppler technique,” said Anglada-Escudé in a university press release. “There are always discussions among scientists about the ways we interpret data but I’m confident that GJ 581d has been in orbit around Gliese 581 all along. In any case, the strength of their statement was way too strong. If the way to treat the data had been right, then some planet search projects at several ground-based observatories would need to be significantly revised as they are all aiming to detect even smaller planets.”

    The upshot is that this new paper challenges the statistical technique used in 2014 to account for the signal being stellar noise — focusing around the presence of starspots in Gliese 581′s photosphere.

    Gliese 581d isn’t the only possible exoplanet that exists around that star — controversy has also been created by another, potentially habitable exoplanet called Gliese 581g. Also originally detected through the wobble of the star, this 3-4 Earth mass world was found to also be in orbit within the habitable zone. But its existence has been the focus of several studies supporting and discounting its presence. Gliese 581 is also home to 3 other confirmed exoplanets, Gliese 581e, b and c.

    Currently, observational data suggests Gliese 581g was just noise, but as the continuing debate about Gliese 581d is proving, this is one controversy that will likely keep on rumbling in the scientific journals for some time.

    See the full article here.

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  • richardmitnick 7:33 pm on March 3, 2015 Permalink | Reply
    Tags: , Exoplanets, , Frank Drake, ,   

    From Space.com: “The Father of SETI: Q&A with Astronomer Frank Drake” 

    space-dot-com logo

    SPACE.com

    February 26, 2015
    Leonard David

    Arecibo Observatory

    Detecting signals from intelligent aliens is a lifelong quest of noted astronomer Frank Drake. He conducted the first modern search for extraterrestrial intelligence (SETI) experiment in 1960. More than five decades later, the hunt remains front-and-center for the scientist.

    5
    Frank Drake

    Drake also devised a thought experiment in 1961 to identify specific factors believed to play a role in the development of civilizations in our galaxy. This experiment took the form of an equation that researchers have used to estimate the possible number of alien civilizations — the famous Drake Equation.

    The Drake equation is:

    N = R*. fp. ne. fl. fi. fc. L

    where:

    N = the number of civilizations in our galaxy with which radio-communication might be possible (i.e. which are on our current past light cone);

    and

    R* = the average rate of star formation in our galaxy
    fp = the fraction of those stars that have planets
    ne = the average number of planets that can potentially support life per star that has planets
    fl = the fraction of planets that could support life that actually develop life at some point
    fi = the fraction of planets with life that actually go on to develop intelligent life (civilizations)
    fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
    L = the length of time for which such civilizations release detectable signals into space

    Drake constructed the “Arecibo Message” of 1974 — the first interstellar message transmitted via radio waves from Earth for the benefit of any extraterrestrial civilization that may be listening.

    The message consists of seven parts that encode the following (from the top down):[4]

    The numbers one (1) to ten (10)
    The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA)
    The formulas for the sugars and bases in the nucleotides of DNA
    The number of nucleotides in DNA, and a graphic of the double helix structure of DNA
    A graphic figure of a human, the dimension (physical height) of an average man, and the human population of Earth
    A graphic of the Solar System indicating which of the planets the message is coming from
    A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish

    3
    This is the message with color added to highlight its separate parts. The actual binary transmission carried no color information.

    Space.com caught up with Drake to discuss the current state of SETI during an exclusive interview at the NASA Innovative Advanced Concepts (NIAC) 2015 symposium, which was held here from Jan. 27 to Jan. 29.

    Drake serves on the NASA NIAC External Council and is chairman emeritus of the SETI Institute in Mountain View, Calif. and director of the Carl Sagan Center for the Study of Life in the Universe.

    Space.com: What’s your view today concerning the status of SETI?

    Frank Drake: The situation with SETI is not good. The enterprise is falling apart for lack of funding. While NASA talks about “Are we alone?” as a number one question, they are putting zero money into searching for intelligent life. There’s a big disconnect there.

    We’re on the precipice. The other thing is that there are actually negative events on the horizon that are being considered.

    Space.com: And those are?

    Drake: There are two instruments, really the powerful ones for answering the “are we alone” question … the Arecibo telescope[above] and the Green Bank Telescope [GBT].

    NRAO GBT
    GBT

    They are the world’s two largest radio telescopes, and both of them are in jeopardy. There are movements afoot to close them down … dismantle them. They are both under the National Science Foundation and they are desperate to cut down the amount of money they are putting into them. And their choice is to just shut them down or to find some arrangement where somebody else steps in and provides funding.

    So this is the worst moment for SETI. And if they really pull the rug out from under the Green Bank Telescope and Arecibo … it’s suicide.

    Space.com: What happens if they close those down?

    Drake: We’re all then sitting in our living rooms and watching science fiction movies.

    Space.com: How about the international scene?

    Drake: The international scene has gone down too because all the relevant countries are cash-strapped also.

    There is a major effort in China, a 500-meter [1,640 feet] aperture spherical radio telescope. The entire reflector is under computer control with actuators. They change the shape of the reflector depending on what direction they are trying to look. The technology is very complicated and challenging. The Russians tried it and it never worked right. But … there are serious resources there.

    Space.com: Why isn’t SETI lively and bouncing along fine given all the detections?

    Drake: You would think. All those planetary detections are the greatest motivator to do SETI that we ever had. But it hasn’t had any impact, at least yet.

    Space.com: How do you reconcile the fact that exoplanet discoveries are on the upswing, yet mum’s the word from ET?

    Drake: People say that all the time … saying that you’ve been searching for years and now you’ve searched thousands of stars and found nothing. Why don’t you just give up … isn’t that the sensible thing?

    There’s a good answer to all that. Use the well-know equation and put in the parameters as we know them. A reasonable lifetime of civilizations is like 10,000 years, which is actually much more than we can justify with our own experience. It works out one in every 10 million stars will have a detectable signal. That’s the actual number. That means, to have a good chance to succeed, you have to look at a million stars at least — and not for 10 minutes — for at least days because the signal may vary in intensity. We haven’t come close to doing that. We just haven’t searched enough.

    Space.com: What are we learning about habitable zones?

    Drake: Actually the case is very much stronger for a huge abundance of life. The story seems to be that almost every star has a planetary system … and also the definition of “habitable zone” has expanded. In our system, it used to be that only Mars and Earth were potentially habitable. Now we’ve got an ocean on Europa … Titan.

    The habitable zone goes out. A habitable zone is not governed just by how far you are from the star, but what your atmosphere is. If you’ve got a lot of atmosphere, you’ve got a greenhouse effect. And that means the planet can be much farther out and be habitable.

    6
    “Radio waving” to extraterrestrials. Outward bound broadcasting from Earth has announced humanity’s technological status to other starfolk, if they are out there listening.
    Credit: Abstruse Goose

    Space.com: What is your view on the debate regarding active SETI — purposely broadcasting signals to extraterrestrials?

    Drake: There is controversy. I’m very against sending, by the way. I think it’s crazy because we’re sending all the time. We have a huge leak rate. It has been going on for years. There is benefit in eavesdropping, and you would have learned everything you can learn through successful SETI searches. There’s all kinds of reasons why sending makes no sense.

    7
    Frank Drake, center, with his colleagues, Optical SETI (OSETI) Principal Investigator Shelley Wright and Rem Stone with the 40-inch Nickel telescope at Lick Observatory in California. Outfitted with the OSETI instrument, the silver rectangular instrument package protrudes from the bottom of the telescope, plus computers, etc.
    Credit: Laurie Hatch Photography

    That reminds me of something else. We have learned, in fact, that gravitational lensing works. If they [aliens] use their star as a gravitational lens, they get this free, gigantic, super-Arecibo free of charge. They are not only picking up our radio signals, but they have been seeing the bonfires of the ancient Egyptians. They can probably tell us more about ourselves than we know … they’ve been watching all these years.

    Space.com: Can you discuss the new optical SETI efforts that you are involved with? You want to search for very brief bursts of optical light possibly sent our way by an extraterrestrial civilization to indicate their presence to us.

    Drake: It’s alive and well. We’ve gotten a couple of people who are actually giving major gifts. There’s no funding problem. There is a new instrument that has been built, and it’s going to be installed at the Lick Observatory [in California] in early March.

    The whole thing is designed to look for laser flashes. The assumption is — and this is where it gets to be tenuous — the extraterrestrials are doing us a favor. It does depend on extraterrestrials helping you by targeting you. These stellar beams are so narrow that you’ve got to know the geometry of the solar system that you’re pointing it at. They want to communicate. They have to be intent on an intentional signal specifically aimed at us. That’s a big order. So there are required actions on the part of the extraterrestrials for this to work. The big plus is that it’s cheap and relatively easy to do.

    See the full article here.

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  • richardmitnick 9:39 am on February 17, 2015 Permalink | Reply
    Tags: , , , , Exoplanets   

    From AAAS: “‘Shadow biosphere’ might be hiding strange life right under our noses” 

    AAAS

    AAAS

    14 February 2015
    Emily Conover

    1
    Scientists have found life on Earth in extreme environments like this Yellowstone hot spring, but alien life might be more elusive.

    If we came across alien life, would we even know it was alive? That was a central question posed at a session here yesterday at the annual meeting of AAAS (which publishes Science). All known life on Earth fits a particular mold, but life from other planets might break free from that mold, making it difficult for us to identify. We could even be oblivious to unfamiliar forms of life right under our noses.

    All life as we know it follows a standard protocol, known as the “central dogma,” using DNA and RNA to store genetic information, and translating that into proteins. And all living things rely on the same handful of chemical elements. So, when searching for life in remote or extreme environments scientists typically look for signs of the kind of life we’re familiar with. But, “if we have other organisms out there that do things just slightly differently, we might miss the boat,” geobiologist Victoria Orphan of the California Institute of Technology in Pasadena told attendees.

    Biologists have proposed the existence of a “shadow biosphere”—an undiscovered group of living things with biochemistry different from what we’re used to. Most of life’s diversity on our planet is too small to see, making microbes the most likely place to look for these new types of life. Already, new discoveries are shaking our beliefs about what life is. Recently discovered giant, amoeba-infecting viruses blur the line between life and nonlife—although they rely on their hosts for essential biological functions, the bacteria-sized viruses have complex genomes. Such unexpected discoveries suggest that we shouldn’t define what we are searching for by what we know is already out there, Orphan said.

    But it’s hard to search for something if you don’t know what it is. One general hallmark to look for, said planetary scientist Carolyn Porco of the Space Science Institute in Boulder, Colorado, is a system that is out of equilibrium. Life takes in and uses energy, altering its environment in the process. Without life, for example, our planet would not have an oxygen-rich atmosphere, as chemical reactions tend to deplete oxygen. The proliferation of left-handed amino acids is another example we see on Earth; life is made up of left-handed amino acids, but not their mirror-images. Such a lopsided situation is an indication of an environment out of whack—and perhaps life.

    However, what we can search for also depends on what’s practical. As a result, NASA’s strategy for searching out life on other planets has generally been to “follow the water,” looking for life similar to that on Earth, Porco said, because that’s what we know how to find. Porco called on other scientists on the panel to come up with a “working definition” of life that could give planetary scientists guidance as to what else they should look for. For example, on other worlds, life might form in liquid hydrocarbons instead of water, such as on Saturn’s moon, Titan. Different markers might reveal life in hydrocarbon seas.

    Rather than searching for new forms of life on Earth or in the stars, other scientists study the question from the bottom up, looking for possible precursors of life. Chemist David Lynn of Emory University in Atlanta points out that misfolded proteins—like the those implicated in neurodegenerative diseases such as Alzheimer’s—show some similarities to life, namely that they can generate diversity in the different ways that they fold, and can undergo chemical evolution, in which those folded proteins are selected not genetically, but chemically. Such precursors could form complex chemical networks, which might be the foundation of radically different life elsewhere in the universe.

    Biochemist John Chaput of Arizona State University, Tempe, takes the approach of working backward from the central dogma, asking if early life could have used a simpler precursor to RNA and DNA. He studies threose nucleic acid, which is not found in nature but can be synthesized in the lab. It forms a similar structure to DNA, but with a different backbone and would’ve been simpler to produce and replicate on primordial Earth. “Life did not choose DNA or RNA out of chemical necessity,” he said. “There may have been many alternative paths to the evolution of life.”

    See the full article here.

    The American Association for the Advancement of Science is an international non-profit organization dedicated to advancing science for the benefit of all people.

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  • richardmitnick 6:39 am on February 14, 2015 Permalink | Reply
    Tags: , , Exoplanets, ,   

    From NBC News: “Weird Sub-Neptunes and Super-Earths Pop Up in Kepler’s Planet Search” 

    NBC News

    NBC News

    February 13th 2015
    Alan Boyle

    One of the most common kinds of planets detected by NASA’s Kepler telescope appears to be a type that doesn’t exist in our own solar system, a leading astronomer on the Kepler team said Friday.

    Habitable planets Current Potential

    NASA Kepler Telescope
    Kepler

    This type of planet has a size in the range between two and four times Earth’s diameter, but it shouldn’t be called a “super-Earth” or a “mini-Neptune,” said Berkeley astronomer Geoff Marcy, one of the world’s most experienced planet-hunters. For now, he’s calling them “sub-Neptunes.”

    Based on an analysis of the Kepler planets’ sizes and densities, sub-Neptunes should have a rocky core that’s swathed in a thick layer of hydrogen and helium gas. That combination distinguishes them from rocky planets like Earth, as well as gas giants like Jupiter and ice giants like Neptune.

    “They dominate the planet census, and yet none of them are found in the solar system,” Marcy said here during a symposium at the annual meeting of the American Association for the Advancement of Science.

    Such planets also have been called “warm Neptunians” or “gas dwarfs.”

    Marcy said the analysis suggests that rocky planets can’t get much larger than 1.5 to two times Earth’s width. But that doesn’t mean we should give up on finding alien analogs to Earth, he said. The Kepler mission’s scientists already have identified scores of planets that are less than twice Earth’s width, and they say our Milky Way galaxy must have lots more such worlds.

    “There are billions of Earth-size planets, and many of them exist in the habitable zone,” said NASA researcher Bill Borucki, the Kepler mission’s principal investigator. “The question is, why hasn’t SETI picked up the signal?”

    Another member of the Kepler science team, Natalia Batalha of San Jose State University and NASA’s Ames Research Center, showed off a list of 29 potential super-Earths that lie within their parent stars’ habitable zones, where liquid water and possibly life could conceivably exist.

    One of the aims of the Kepler mission is to identify potentially habitable Earth-class planets, a category known as eta-earth.

    “We now have a very highly reliable sample of small-planet candidates in the habitable zone of both M- and K-type stars [red and orange dwarfs] that will enable an eta-Earth determination for this class of stars,” Batalha said.

    She added that similar determinations may be made for some of the small planets that Kepler has detected around sunlike stars, known as G-type stars. However, it’s still debatable whether the candidates on Kepler’s current list should be classified as rocky planets in the traditional sense, or as sub-Neptunes.

    Batalha’s list doesn’t yet include any Earth-size planets in Earthlike orbits around sunlike stars, but after Friday’s symposium, she hinted that it may not be long before such long-sought worlds start popping up in the Kepler database.

    “There are going to be more,” she told NBC News.

    See the full article here.

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  • richardmitnick 2:45 pm on January 30, 2015 Permalink | Reply
    Tags: , , , Exoplanets   

    From ESO- “ESOcast 71: New Exoplanet-hunting Telescopes on Paranal” 


    European Southern Observatory

    This ESOcast takes a close look at an unusual new group of small telescopes that has recently achieved first light at ESO’s Paranal Observatory in northern Chile.

    Watch, enjoy, learn.

    See the full article here.

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  • richardmitnick 6:07 am on January 24, 2015 Permalink | Reply
    Tags: , Exoplanets,   

    From LLNL: “New research re-creates planet formation, super-Earths and giant planets in the laboratory” 


    Lawrence Livermore National Laboratory

    Jan. 22, 2015

    Breanna Bishop
    bishop33@llnl.gov
    925-423-9802

    1
    New laser-driven shock compression experiments on stishovite, a high-density form of silica, provide thermodynamic and electrical conductivity data at unprecedented conditions and reveal the unusual properties of rocks deep inside large exoplanets and giant planets. Photo by E. Kowaluk, LLE

    New laser-driven compression experiments reproduce the conditions deep inside exotic super-Earths and giant planet cores, and the conditions during the violent birth of Earth-like planets, documenting the material properties that determined planet formation and evolution processes.

    The experiments, reported in the Jan. 23 edition of Science, reveal the unusual properties of silica — the key constituent of rock — under the extreme pressures and temperatures relevant to planetary formation and interior evolution.

    Using laser-driven shock compression and ultrafast diagnostics, Lawrence Livermore National Laboratory (LLNL) physicist Marius Millot and colleagues from Bayreuth University (Germany), LLNL and the University of California, Berkeley were able to measure the melting temperature of silica at 500 GPa (5 million atmospheres), a pressure comparable to the core-mantle boundary pressure for a super-Earth planet (5 Earth masses), Uranus and Neptune. It also is the regime of giant impacts that characterize the final stages of planet formation.

    “Deep inside planets, extreme density, pressure and temperature strongly modify the properties of the constituent materials,” Millot said. “How much heat solids can sustain before melting under pressure is key to determining a planet’s internal structure and evolution, and now we can measure it directly in the laboratory.”

    In combination with prior melting measurements on other oxides and on iron, the new data indicate that mantle silicates and core metal have comparable melting temperatures above 300-500 GPa, suggesting that large rocky planets may commonly have long-lived oceans of magma – molten rock – at depth. Planetary magnetic fields can be formed in this liquid-rock layer.

    “In addition, our research suggests that silica is likely solid inside Neptune, Uranus, Saturn and Jupiter cores, which sets new constraints on future improved models for the structure and evolution of these planets,” Millot said.

    Those advances were made possible by a breakthrough in high-pressure crystal growth techniques at Bayreuth University in Germany. There, Natalia Dubrovinskaia and colleagues managed to synthesize millimeter-sized transparent polycrystals and single crystals of stishovite, a high-density form of silica (SiO2) usually found only in minute amounts near meteor-impact craters.

    Those crystals allowed Millot and colleagues to conduct the first laser-driven shock compression study of stishovite using ultrafast optical pyrometry and velocimetry at the Omega Laser Facility at the University of Rochester’s Laboratory for Laser Energetics.

    “Stishovite, being much denser than quartz or fused-silica, stays cooler under shock compression, and that allowed us to measure the melting temperature at a much higher pressure,” Millot said. “Dynamic compression of planetary-relevant materials is a very exciting field right now. Deep inside planets hydrogen is a metallic fluid, helium rains, fluid silica is a metal and water may be superionic.”

    In fact, the recent discovery of more than 1,000 exoplanets orbiting other stars in our galaxy reveals the broad diversity of planetary systems, planet sizes and properties. It also sets a quest for habitable worlds hosting extraterrestrial life and shines new light on our own solar system. Using the ability to reproduce in the laboratory the extreme conditions deep inside giant planets, as well as during planet formation, Millot and colleagues plan to study the exotic behavior of the main planetary constituents using dynamic compression to contribute to a better understanding of the formation of the Earth and the origin of life.

    Co-authors on this paper include David Braun, Peter Celliers, Gilbert Collins and Jon Eggert of LLNL; Natalia Dubrovinskaia, Ana Černok, Stephan Blaha and Leonid Dubrovinsky of Bayreuth University; and Raymond Jeanloz of the University of California, Berkeley.

    See the full article here.

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  • richardmitnick 12:15 pm on January 18, 2015 Permalink | Reply
    Tags: , , Exoplanets, U Toronto   

    From U Toronto: “Planets outside our solar system more hospitable to life than we’d thought” 

    U Toronto Bloc

    University of Toronto

    Jan 16, 20015
    Sean Bettam

    A study by astrophysicists at the University of Toronto suggests that exoplanets – planets outside our solar system – are more likely to have liquid water and be more habitable than we thought.

    1
    Artist’s impression of the exoplanet Tau Boötis b (image by: ESO/L. Calçada)

    “Planets with potential oceans could have a climate that is much more similar to Earth’s than previously expected,” said Jérémy Leconte, a postdoctoral fellow at the Canadian Institute for Theoretical Astrophysics (CITA) and the Centre for Planetary Sciences at the University of Toronto, and lead author of a study published January 15 in Science Express.

    Scientists have thought that exoplanets behave in a manner contrary to that of Earth – that is, they always show their same side to their star. If so, exoplanets would rotate in sync with their star so that there is always one hemisphere facing it while the other hemisphere is in perpetual cold darkness.

    Leconte’s study suggests, however, that as exoplanets rotate around their stars, they spin at such a speed as to exhibit a day-night cycle similar to Earth.

    “If we are correct, there is no permanent, cold night side on exoplanets causing water to remain trapped in a gigantic ice sheet. Whether this new understanding of exoplanets’ climate increases the ability of these planets to develop life remains an open question.”

    Leconte and his team reached their conclusions via a three-dimensional climate model they developed to predict the effect of a given planet’s atmosphere on the speed of its rotation, which results in changes to its climate,” said Leconte. “Atmosphere is a key factor affecting a planet’s spin, the impact of which can be of enough significance to overcome synchronous rotation and put a planet in a day-night cycle.”

    Though astronomers are still awaiting observational evidence, theoretical arguments suggest that many exoplanets should be able to maintain an atmosphere as massive as that of Earth. In Earth’s case – with its relatively thin atmosphere – most of the light from the Sun reaches the surface of the planet, maximizing the effect of heating throughout the atmosphere and producing a more moderate climate across the planet. By creating temperature differences at the surface, between day and night and between equator and poles, the solar heating drives winds that redistribute the mass of the atmosphere.

    The impact is so significant that it overcomes the effect of tidal friction exerted by a star on whatever satellite is orbiting it, much like Earth does on the Moon.

    “The Moon always shows us the same side, because the tides raised by Earth create a friction that alters its spin,” said Leconte. “The Moon is in synchronous rotation with Earth because the time it takes to spin once on its axis equals the time it takes for it to orbit around Earth. That is why there is a dark side of the moon. The tidal theory, however, neglects the effects of an atmosphere.”

    The researchers say that a large number of known terrestrial exoplanets should not be in a state of synchronous rotation, as initially believed. While their models show that they would have a day-night cycle making them much more similar to Earth, the duration of their days could last between a few weeks and a few months.

    The findings are reported in the paper Asynchronous rotation of Earth-mass planets in the habitable zone of lower-mass stars published January 15 in Science Express. The work was supported by grants from the Natural Sciences and Engineering Research Council of Canada.

    See the full article here.

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    Established in 1827, the University of Toronto has one of the strongest research and teaching faculties in North America, presenting top students at all levels with an intellectual environment unmatched in depth and breadth on any other Canadian campus.

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  • richardmitnick 7:26 am on January 14, 2015 Permalink | Reply
    Tags: , , , Exoplanets   

    From ESO: “New Exoplanet-hunting Telescopes on Paranal” 


    European Southern Observatory

    14 January 2015
    Peter Wheatley
    University of Warwick
    Coventry, United Kingdom
    Tel: +44 247 657 4330
    Email: P.J.Wheatley@warwick.ac.uk

    Heike Rauer
    Deutsches Zentrum für Luft- und Raumfahrt (DLR) / Institut für Planetenforschung
    Berlin, Germany
    Tel: +49 30 67055 430
    Email: heike.rauer@dlr.de

    Stéphane Udry
    Observatoire de l’Université de Genève
    Geneva, Switzerland
    Tel: +41 22 379 24 67
    Email: stephane.udry@unige.ch

    Ather Mirza
    University of Leicester
    Leicester, United Kingdom
    Tel: +44 116 252 3335
    Email: pressoffice@le.ac.uk

    David Azocar
    Universidad de Chile
    Santiago, Chile
    Email: dazocar@das.uchile.cl

    Richard Hook
    ESO Public Information Officer
    Garching bei München, Germany

    Tel: +49 89 3200 6655
    Email: rhook@eso.org

    The Next-Generation Transit Survey (NGTS) has achieved first light at ESO’s Paranal Observatory in northern Chile. This project will search for transiting exoplanets — planets that pass in front of their parent star and hence produce a slight dimming of the star’s light that can be detected by sensitive instruments. The telescopes will focus on discovering Neptune-sized and smaller planets, with diameters between two and eight times that of Earth.

    1

    ESO Paranal Facilities
    ESO/Paranal

    The Next-Generation Transit Survey (NGTS) is a wide-field observing system made up of an array of twelve telescopes, each with an aperture of 20 centimetres [1]. This new facility, built by a UK, Swiss and German consortium, is located at ESO’s Paranal Observatory in northern Chile and benefits from the superb observing conditions and excellent support facilities available at this site.

    “We needed a site where there were many clear nights and the air was clear and dry so that we could make very accurate measurements as often as possible — Paranal was the best choice by far,” says Don Pollacco of the University of Warwick in the UK and one of the NGTS project leads.

    NGTS is designed to operate in a robotic mode and it will continuously monitor the brightness of hundreds of thousands of comparatively bright stars in the southern skies. It is searching for transiting exoplanets and will reach a level of accuracy in measuring the brightness of stars — one part in a thousand — that has never before been attained with a ground-based wide-field survey instrument [2].

    This great accuracy of brightness measurement, across a wide field, is technically demanding, but all the key technologies needed for NGTS were demonstrated using a smaller prototype system, which operated on La Palma in the Canary Islands during 2009 and 2010. NGTS also builds on the success of the SuperWASP experiment, which up to now leads in the detection of large gaseous planets.

    The discoveries of NGTS will be studied further using other larger telescopes, including the ESO Very Large Telescope[pictured above]. One goal is to find small planets that are bright enough for the planetary mass to be measured. This will allow planetary densities to be deduced, which in turn provides clues about the composition of the planets. It may also be possible to probe the atmospheres of the exoplanets whilst they are in transit. During the transit some of the star’s light passes through the planet’s atmosphere, if it has one, and leaves a tiny, but detectable, signature. So far only a few such very delicate observations have been made, but NGTS should provide many more potential targets.

    This is the first telescope project hosted, but not operated, by ESO on Paranal. Several telescope projects operating under similar arrangements are already at work at the older La Silla Observatory. The NGTS data will flow into the ESO archive system and will be available to astronomers worldwide for decades to come.

    ESO LaSilla Long View
    ESO at LaSilla

    Peter Wheatley, one of the NGTS project leads from the University of Warwick, concludes: “We are excited to begin our search for small planets around nearby stars. The NGTS discoveries, and follow-up observations by telescopes on the ground and in space, will be important steps in our quest to study the atmospheres and composition of small planets such as the Earth.”

    The NGTS Consortium is composed of the University of Warwick, UK; the Queen’s University of Belfast, UK; the University of Leicester, UK; the University of Cambridge, UK; Geneva University, Switzerland and DLR Berlin, Germany.
    Notes

    [1] The NGTS telescopes are modified versions of small high-quality commercial telescopes made by Astro Systeme Austria (ASA). The NGTS cameras are modified ikon-L cameras by Andor Technology Ltd (http://www.andor.com) built around red-sensitive deep-depletion CCDs by e2v (http://www.e2v.com).

    [2] NASA’s orbiting Kepler mission has a higher accuracy of stellar brightness measurement but probes a smaller region of the sky than NGTS. The wider NGTS search will find brighter examples of small exoplanets that are better suited for detailed study.

    NASA Kepler Telescope
    NASA/Kepler

    See the full article here.

    SuperWASP telescope
    SuperWASP is the UK’s leading extra-solar planet detection programme. It originally comprised a consortium of eight academic institutions: Cambridge University, the Instituto de Astrofisica de Canarias, the Isaac Newton Group of telescopes, Keele University, Leicester University, the Open University, Queen’s University Belfast and St. Andrews University. The WASP project is currently funded and operated by Warwick University and Keele University.

    SuperWASP consists of two robotic observatories that operate continuously all year around, allowing us to cover both hemispheres of the sky. The first, SuperWASP-North is located on the island of La Palma amongst the Isaac Newton Group of telescopes (ING). The second, SuperWASP-South is located at the site of the South African Astronomical Observatory (SAAO), just outside Sutherland, South Africa. The observatories each consist of eight wide-angle cameras that simultaneously monitor the sky for planetary transit events. A transit occurs when a planet passes in front of its parent star temporarily blocking some of the light from it. The eight wide-angle cameras allow us to monitor millions of stars simultaneously enabling us to detect the rare transit events.

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