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  • May 23, 2017
  • 07:06 AM
  • 69 views

Multi-Loop Structure of Nonthermal Microwave Sources in a Major Long-Duration Flare by V. Grechnev et al.*

by CESRA in Solar Radio Science

Hard X-ray (HXR) and microwave observations of flares show only a few nonthermal sources. They are simple and compact, especially in impulsive flares, suggesting involvement of one to two loops. Hanaoka (1996) and Nishio et al. (1997) interpreted these observations in terms of double-loop flares. This view was later extended up to long-duration flares (Tzatzakis, Nindos, and Alissandrakis, 2008). A concept of a simple flare loop became dominant. However, observations [...]... Read more »

  • May 16, 2017
  • 07:04 AM
  • 18 views

Comparison of alternative zebra-structure models in solar radio emission by G.P. Chernov et al.*

by CESRA in Solar Radio Science

Discussion about the nature of zebra-structure (ZS) in type IV radio bursts continues, despite the ten proposed models. First of all, this is due to the wide variety of stripes in each new phenomenon, making the explanation of all the fine details by any one mechanism becomes impossible. The most widespread explanation is the emission at different levels of double plasma resonance (DPR), sequential on the height surfaces in the magnetic [...]... Read more »

G. P. Chernov, V. V. Fomichev, & R. A. Sych. (2017) Comparison of alternative zebra-structure models in solar radio emission. submitted to Astronomy Letter Journal. arXiv: 1704.02528v1

  • May 9, 2017
  • 07:07 AM
  • 181 views

Microwave emission as a proxy of CME speed in ICME forecasting by Carolina Salas Matamoros, Ludwig Klein and Gerard Trottet

by CESRA in Solar Radio Science

Coronal Mass Ejections (CMEs) are one type of interplanetary structure that mostly affect the geomagnetic field (e.g. Gonzalez and Tsurutani, 1987; Zhang et al, 2007). These structures are observed and studied through coronagraphic images. The basic limitation of the coronagraph is that it shows the corona only in the plane of the sky, and blocks by necessity the view on the solar disk. Thus, the projection effect in the kinematic [...]... Read more »

  • May 8, 2017
  • 11:54 PM
  • 152 views

Quick Look: The Thermal Structure of the Venus Atmosphere

by Paul Wren in Venus Dispatches

SummaryFor two years beginning in 2013, a large team led by Sanjay Limaye set out to combine and compare the following:Venusian atmospheric data collected by probes in the 1970s and 1980s (used to create the Venus International Reference Atmosphere, or VIRA)Venus Express data on the vertical and horizontal structure of the atmosphereEarth-based observations of the upper atmosphere temperature structure of Venus made since VIRAFigure 1a: Vertical coverage of post-VIRA atmospheric structure experiments.This work is seen as the first step toward creating an updated VIRA model. You can read it here.Reference:Limaye, S., Lebonnois, S., Mahieux, A., Pätzold, M., Bougher, S., Bruinsma, S., Chamberlain, S., Clancy, R., Gérard, J., Gilli, G., Grassi, D., Haus, R., Herrmann, M., Imamura, T., Kohler, E., Krause, P., Migliorini, A., Montmessin, F., Pere, C., Persson, M., Piccialli, A., Rengel, M., Rodin, A., Sandor, B., Sornig, M., Svedhem, H., Tellmann, S., Tanga, P., Vandaele, A., Widemann, T., Wilson, C., Müller-Wodarg, I., & Zasova, L. (2017). The Thermal Structure of the Venus Atmosphere: Intercomparison of Venus Express and Ground Based Observations of Vertical Temperature and Density Profiles Icarus DOI: 10.1016/j.icarus.2017.04.020... Read more »

  • April 26, 2017
  • 11:33 PM
  • 68 views

Recently Active Lava Flows on Idunn Mons

by Paul Wren in Venus Dispatches

OverviewCombined VIRTIS emissivity and Magellan SAR image of Idunn MonsIn Idunn Mons on Venus: Location and extent of recently active lava flows, Piero D'Incecco and his colleagues looked closer at 1 µm thermal emissivity anomalies on the eastern flank of Idunn Mons, as observed by the VIRTIS instrument on Venus Express. Hypothesizing that recent lava flows were responsible, they overlayed the VIRTIS emissivity data with SAR images from the Magellan mission to look for lava flows that may have resulted in the high emissivity. They created a geologic map of lava flow units on the eastern flank, creating outlines on Magellan SAR images. They then used software that models the best fit of emissivity data to the flow areas. What Did They Find?They conclude that the lava flow units on the eastern flank of Idunn Mons are likely responsible for relatively high 1µm emissivity observed by VIRTIS. This is consistent with their reconstructed stratigraphy (i.e., relative ages) of the various lava flow units. They also note that the average microwave emissivity of the lava flows is consistent with dry basalts (i.e., cooled volcanic rock), and also may indicate limited chemical weathering. Why Is It Important?Their data are consistent with lava flows that are young enough that they have not experienced significant weathering, and may represent recent or even active volcanism on the surface of Venus. The authors look forward to new data to be collected by VERITAS, a Discovery Program finalist mission that sadly, was not selected. References:D'Incecco, P., Müller, N., Helbert, J., & D'Amore, M. (2017). Idunn Mons on Venus: Location and extent of recently active lava flows Planetary and Space Science, 136, 25-33 DOI: 10.1016/j.pss.2016.12.002... Read more »

D'Incecco, P., Müller, N., Helbert, J., & D'Amore, M. (2017) Idunn Mons on Venus: Location and extent of recently active lava flows. Planetary and Space Science, 25-33. DOI: 10.1016/j.pss.2016.12.002  

  • April 25, 2017
  • 07:02 AM
  • 212 views

The Brightness Temperature of the Quiet Solar Chromosphere at 2.6 mm by Kazumasa Iwai et al

by CESRA in Solar Radio Science

The brightness temperature of the Sun constitutes a basic property of the solar atmosphere. The main emission mechanism of the Sun at millimeter and submillimeter wavelengths is thermal free–free emission from the chromosphere, which is an atmospheric layer with a temperature ranging between 6000 to 20,000 K. The opacity of thermal free–free emission depends on the temperature and density in the emission region. In addition, the Rayleigh– Jeans law is applicable [...]... Read more »

Iwai, K., Shimojo, M., Asayama, S., Minamidani, T., White, S., Bastian, T., & Saito, M. (2017) The Brightness Temperature of the Quiet Solar Chromosphere at 2.6 mm. Solar Physics, 292(1). DOI: 10.1007/s11207-016-1044-5  

  • April 21, 2017
  • 12:02 PM
  • 68 views

Spectral Guide for Earth-based Observers to Complement Akatsuki Mission

by Paul Wren in Venus Dispatches

OverviewMeant as a guide for Earth-based observers of Venus (professional and amateur), Overview of useful spectral regions for Venus: An update to encourage observations complementary to the Akatsuki mission provides detailed information regarding the wavelengths at which observations should be made to complement the Akatsuki mission at Venus.Two tables (one for day side observing, the other for night side) provide opportunities across a "spectrum" of wavelengths, indicating what products are likely involved, the altitude being observed at that wavelength, and the suspected processes occurring there.  Citations to previous work at the various wavelengths are also provided.The paper is available to all under a Creative Commons License.References:Peralta, J., Lee, Y., McGouldrick, K., Sagawa, H., Sánchez-Lavega, A., Imamura, T., Widemann, T., & Nakamura, M. (2017). Overview of useful spectral regions for Venus: An update to encourage observations complementary to the Akatsuki mission Icarus, 288, 235-239 DOI: 10.1016/j.icarus.2017.01.027... Read more »

  • April 18, 2017
  • 12:43 PM
  • 64 views

Bright highlands in equatorial Venus likely ferro-electric. What's up with the high-latitude highlands?

by Paul Wren in Venus Dispatches

OverviewA lot of papers have been written about the highly reflective highlands (in radar) on Venus, with several different hypotheses (e.g. high porosity, metal frost).  Allan Treiman, Elise Harrington, and Virgil Sharpton look specifically at high-latitude highlands in comparison to highlands in the equatorial regions.  Both areas feature high reflectivity, but the reflectance patterns are distinct, as they describe in Venus' radar-bright highlands: Different signatures and materials on Ovda Regio and on Maxwell Montes.What Did They Find?They have confirmed earlier studies showing that the reflectance pattern seen in equatorial highlands "Snow Line" from N flank of Maxwell Montes (from Fig. 4c)(such as Ovda Regio) are consistent with a ferro-electric substance, likely chlorapatite.The reflectance patterns on Maxwell Montes (~60°N) are different.  The backscatter abruptly transitions from low to high at the previously identified "snow line" (~4.5km elevation), and stays high above that point.They believe this pattern indicates a semiconductor material.  How did it get there? Either by precipitation from the atmosphere (frost?), or it formed as the result of a chemical reaction between the surface and atmosphere.Why Is It Important?At the very least, their research shows that even though the highlands of Ovda Regio (equatorial) and Maxwell Montes (high latitude) are similarly reflective, they are caused by different materials or processes.The authors urge (and I agree) that lander missions with geochemical analysis instruments be sent to multiple highland locations.References:Treiman, A., Harrington, E., & Sharpton, V. (2016). Venus’ radar-bright highlands: Different signatures and materials on Ovda Regio and on Maxwell Montes Icarus, 280, 172-182 DOI: 10.1016/j.icarus.2016.07.001... Read more »

  • April 17, 2017
  • 12:20 AM
  • 49 views

Discovery of a 150 day period in the Venus condensational clouds

by Paul Wren in Venus Dispatches

OverviewUsing near infrared (NIR) data from the VIRTIS instrument that once traveled aboard the Venus Express spacecraft, Kevin McGouldrick and Constantine C. C. Tsang found a periodic variation in radiance, most intense at the mid-latitudes.  The paper is here.What Did They Find?They identified A 150-day periodic variation in radiance within the 1.74 µm and 2.30 µm windows, which is most pronounced between 30° and 60° latitude.  They also found that in these mid-latitudes, radiance at these wavelengths steadily increased throughout the life of the instrument. Why Is It Important?The 150-day timescale is consistent with a model (developed by McGouldrick) of the Venusian condensational clouds vertical structure, driven by radiative-dynamical feedback.  I'm not sure what that means, but thank goodness the paper is open source!References McGouldrick, K., & Tsang, C. (2017). Discovery of a 150 day period in the Venus condensational clouds Icarus, 286, 118-133 DOI: 10.1016/j.icarus.2016.10.005 ... Read more »

  • April 11, 2017
  • 09:00 AM
  • 334 views

Looking for clues for past life on Mars

by EE Giorgi in CHIMERAS

NASA's Curiosity Mars. Credits: NASA/JPL-Caltech/MSSSOn August 6, 2012, the NASA Curiosity rover landed on Mars at the base of Mount Sharp, a mountain the size of Kilimanjaro (~19,000 feet) in the middle of Gale Crater. Nina Lanza, space scientist at the Los Alamos National Laboratory, remembers the day well. As part of the team that built ChemCam, one of the ten instruments on the rover, she spent three months at the Jet Propulsion Laboratory in California, living on “Mars time” to follow Curiosity’s first “steps.” ChemCam stands for “chemistry camera” and comprises a laser-induced breakdown spectroscopy (LIBS) instrument and a Remote Micro Imager (RMI). It was built at the Los Alamos National Laboratory in collaboration with the French space agency CNES. Nina Lanza and postdoctoral fellow Patrick Gasda are two of the Los Alamos scientists who work on the instrument. “We get to shoot a laser on Mars for a living,” Lanza says, grinning.And the laser on ChemCam is extremely powerful. When focused on a target, it vaporizes a small amount of material by heating Martian rocks to a temperature that’s roughly equivalent to that of the surface of the sun. “When we fire at a nearby target,” Gasda explains, “the elements get excited and, as they come down from that excited state, they emit light.”By looking at the light emitted by the target, scientists can analyze the composition of rocks and soils on Mars. Previous Mars missions have found ice in the near-surface at high latitudes, begging the question: was there ever water on other parts of Mars at some point? And if there was—does that mean there could have been life, too?With the very first laser shots from ChemCam, the answer was a definitive yes. “ChemCam discovered that all Martian dust is hydrated,” Lanza explains. “Given how dusty Mars is, this means that water is everywhere on the planet. We also found evidence that water was flowing in Mars’s past.” “Gale Crater was filled with water,” Gasda adds. “From the sequence of sedimentary rocks we know of flowing streams in the crater that converged to a large body of still water that likely lasted for millions of years.”“Curiosity gave us a picture of Gale Crater as an extremely habitable system,” Lanza continues. “We know that on Earth systems like this, with long-lasting neutral pH waters, would definitely support life.”But how do you go about finding evidence for life? You search for clues, in other words, unique markers that identify biological activity.“A potential marker could be manganese minerals,” Lanza says. In 2016 Curiosity found rocks rich in manganese-oxides at a location called Kimberley. “Manganese deposits in the terrestrial geological record mark the shift to higher concentrations of atmospheric oxygen due to the emergence of photosynthesis. This means that there could have been more oxygen in the Martian atmosphere in the past.” Water. Oxygen. What about other building blocks of life? How do we look for those?“Nucleic and amino acids have been found in space,” Gasda tells me. “However, ribose—the ‘R’ in RNA, one of the first building blocks of life—and other sugars have never been found in space because they are too unstable. In order to have life, you need molecules that stabilize these sugars in water. Borates are particularly promising molecules for stabilizing sugars [1].”Boron is highly soluble in water. In 2013 researchers from the University of Hawaii found boron in a meteorite from Mars [2]. That’s when Gasda became interested in this quest. “Once we knew that Gale Crater had once hosted a large body of water, it was natural to search for boron in those sediments.” ChemCam did indeed find boron on Mars in 2016. Together with the manganese oxides, this is still not sufficient evidence for life on Mars, but it shows that some of the raw ingredients were present. The scientists are primed to keep looking. Curiosity has been on Mars almost five years (or 1660 sols), and its data is helping researchers fine-tune the instruments for the next Mars rover, provisionally named Mars 2020, to be launched in July 2020. “We need to look for biosignatures,” Lanza says. “And we may not find them. But if we don’t, to me, the most striking question would be: what if there were indeed all the ingredients for life on Mars, yet life never happened? What made Earth so unique that life could happen here but nowhere else?”Gasda nods. “And if we are indeed unique, shouldn’t this make us feel more special, and make us more cautious about the way we treat our planet and our biodiversity?” I mention the current political climate, with the planned budget cuts to scientific research, and the appalling denial of any intervention to curb global warming. “These cuts to basic research are disheartening,” Lanza says. “People often think of NASA research as esoteric and out of touch. And yet almost everyone has GPS technology on their smart phones today, something we owe to space research. Take the electron as another example. I’m sure people in the nineteenth century found J. J. Thomson’s research on the electron to be highly academic, with few practical applications. Yet without his discovery we wouldn’t have electricity, and our lives today would be fundamentally different.” “The best measure for progress,” Lanza concludes, “is when you can’t imagine the knowledge you are going to gain. Let the science surprise you.” Nina Lanza is a staff scientist, and Patrick Gasda is a postdoctoral research fellow, both in the Space and Remote Sensing group at the Los Alamos National Laboratory. They are both on the science team for the Curiosity Mars rover mission. The opinions expressed here are their own and not their employer’s. Both will be speaking at the March for Science in Santa Fe, New Mexico, on April 22nd. [1] Ricardo, A. (2004). Borate Minerals Stabilize Ribose Science, 303 (5655), 196-196 DOI: 10.1126/science.1092464[2] Stephenson, J., Hallis, L., Nagashima, K., & Freeland, S. (2013). Boron Enrichment in Martian Clay PLoS ONE, 8 (6) DOI: 10.1371/journal.pone.0064624... Read more »

Ricardo, A. (2004) Borate Minerals Stabilize Ribose. Science, 303(5655), 196-196. DOI: 10.1126/science.1092464  

Stephenson, J., Hallis, L., Nagashima, K., & Freeland, S. (2013) Boron Enrichment in Martian Clay. PLoS ONE, 8(6). DOI: 10.1371/journal.pone.0064624  

  • April 11, 2017
  • 06:34 AM
  • 293 views

How Electron Beams Produce Continuous Coherent Plasma Emission by H. Che, M. Goldstein, P. Diamond, and R. Sagdeev

by CESRA in Solar Radio Science

It is commonly accepted that energetic electron beams can produce drift frequency radio emission or Type III bursts since Ginzburg and Zhelezniakov first proposed the idea in 1958. However, the electron two-stream instability time (see reference 2) in the corona is fraction of a second, while the duration of coronal Type III bursts lasts several orders of magnitude longer. This problem is called the “Sturrock Dilemma” and remains a subject [...]... Read more »

  • March 28, 2017
  • 08:04 AM
  • 255 views

Radio Diagnostics of Electron Acceleration Sites During the Eruption of a Flux Rope in the Solar Corona by Eoin Carley et al.*

by CESRA in Solar Radio Science

Flares and coronal mass ejections (CMEs) are thought to result from magnetic energy release in the solar corona, often involving the destabilisation of a twisted magnetic structure known as a flux rope (Chen et al. 2011, Webb et al. 2012). This activity may be accompanied by the acceleration of electrons (Kahler 2007, Lin et al. 2011). However, there is ongoing debate on exactly where, when and how this particle acceleration occurs [...]... Read more »

  • March 14, 2017
  • 08:05 AM
  • 326 views

Solar Science with the Atacama Large Millimeter/Submillimeter Array — A New View of Our Sun by S. Wedemeyer

by CESRA in Solar Radio Science

The Atacama Large Millimeter/submillimeter Array (ALMA), which consists of 66 antennas placed on the Chajnantor plateau in the Chilean Andes, has already produced impressive results for a large range of astronomical objects. Regular observations of the Sun have been carried out for the first time in December 2016 and exciting results can be expected soon. ALMA combines high spatial, temporal, and spectral resolution with the diagnostic advantages of radiation at [...]... Read more »

Wedemeyer, S., Bastian, T., Brajša, R., Hudson, H., Fleishman, G., Loukitcheva, M., Fleck, B., Kontar, E., De Pontieu, B., Yagoubov, P.... (2015) Solar Science with the Atacama Large Millimeter/Submillimeter Array—A New View of Our Sun. Space Science Reviews, 200(1-4), 1-73. DOI: 10.1007/s11214-015-0229-9  

  • February 28, 2017
  • 07:03 AM
  • 275 views

Quasi-periodic acceleration of electrons in the flare on 2012 July 19 by Jing Huang et al.*

by CESRA in Solar Radio Science

We study the quasi-periodic pulsations (QPPs) of nonthermal emission in an M7.7 class flare on 2012 July 19 with spatially resolved observations at microwave and HXR bands and with spectral observations at decimetric, metric waves. Microwave emission at 17 GHz of two footpoints, HXR emission at 20–50 keV of the north footpoint and loop top, and type III bursts at 0.7–3 GHz show prominent in-phase oscillations at 270$\,$s. Through the [...]... Read more »

Huang, J., Kontar, E., Nakariakov, V., & Gao, G. (2016) QUASI-PERIODIC ACCELERATION OF ELECTRONS IN THE FLARE ON 2012 JULY 19. The Astrophysical Journal, 831(2), 119. DOI: 10.3847/0004-637X/831/2/119  

  • February 14, 2017
  • 07:02 AM
  • 434 views

Large-scale simulations of Langmuir Wave Distributions Induced by Electron Beams by H. Reid and E. Kontar

by CESRA in Solar Radio Science

Langmuir waves that generate type III radio bursts are excited by high-energy electron beams streaming out from the corona through interplanetary space. Despite a smooth temporal distribution of electrons, the Langmuir waves are measured to occur in discrete clumps, commonly attributed to the turbulent nature of the solar wind electron density (e.g. Smith and Sime 1979, Melrose et al 1986). But how do fluctuations in the background plasma shape the [...]... Read more »

  • January 31, 2017
  • 07:06 AM
  • 640 views

Emission of radiation by plasmas with counter-streaming electron beams by L. F. Ziebell et al.*

by CESRA in Solar Radio Science

The phenomena of emission of radiation by the Sun, which are known as type II and type III solar radio bursts, have been known and investigated for more than sixty years. The bursts of radiation occur at a frequency corresponding to the plasma frequency at the source region, and harmonics [...]... Read more »

Ziebell, L., Petruzzellis, L., Yoon, P., Gaelzer, R., & Pavan, J. (2016) PLASMA EMISSION BY COUNTER-STREAMING ELECTRON BEAMS. The Astrophysical Journal, 818(1), 61. DOI: 10.3847/0004-637X/818/1/61  

  • January 17, 2017
  • 07:03 AM
  • 435 views

Simultaneous near-Sun observations of a moving type IV radio burst and the associated white-light CME by K. Hariharan et al.*

by CESRA in Solar Radio Science

Quasi-continuum radio emissions of duration ~10-60 min that occur along with flares and coronal mass ejections (CMEs) in the solar atmosphere are termed as type IV bursts. The bursts are non-thermal in nature and can be classified into two categories, i.e. moving type IV (type IVm) bursts and stationary type [...]... Read more »

  • January 3, 2017
  • 07:01 AM
  • 455 views

Observation of quasi-periodic solar radio bursts associated with propagating fast-mode waves by C. R. Goddard et al.*

by CESRA in Solar Radio Science

Flaring activity on the Sun triggers waves and oscillations in the solar corona. The study of these waves and oscillations allows comparisons to magnetohydrodynamic (MHD) theory and modelling to be made, and seismological inversions based on this comparison allow local plasma parameters to be measured indirectly (e.g. De Moortel & [...]... Read more »

  • December 27, 2016
  • 02:04 PM
  • 689 views

Why we have not met Aliens yet?

by Usman Paracha in SayPeople

A huge of number of people keeps on thinking about the existence of some other intelligent beings in the universe but still we have not met any aliens. Why?

Earth is rare

Earth is special planet

One of the reasons that we have not met aliens is that Earth is rare and there is nothing just like Earth in the universe. In this regard, Paleontologist Peter Ward and astronomer Donald Brownlee presented the Rare Earth Hypothesis about 17 years ago.

According to the Rare Earth Hypothesis, the planets having Earth-like complex (animal) life, according to our knowledge, are very rare in the universe. Moreover, the chains of events that occurred on this planet and that were important for the development of life are so complex that they would not occur anywhere in the universe; thereby, making it highly improbable to meet aliens from other planets.

Picture showing wreckage

Every intelligent life may face some disasters after reaching a sufficiently advanced technology

Even though some alien life exists in the universe, Great Filter Theory suggests that it is probably difficult for the alien or intelligent life in the universe to reach such a technologically advancing stage that they start long-distance space travel or communication.

On the Earth, we know that some natural disasters often occur taking the life many years back; thereby, causing the people to start the life from somewhat beginning. For example, our advancements in nuclear technology could take us to nuclear war finally leading to mass destruction, and loss of advanced technology and many important human beings, i.e. great filter. Similar events, i.e. cataclysmic natural disasters, could also occur on other planets having some alien lives causing them to start their life from zero, and finally, making it almost impossible for them to go somewhere in the universe.

Another similar concept is that of the Medea Hypothesis, noted by paleontologist Peter Ward that suggests the concept of self-destruction. This hypothesis shows that the internal suicidal clock of living beings runs out before making any connection with aliens.

Technology at small scale

Why move outward when inward has much to give?

John Smart’s Transcension Hypothesis suggests that intelligent life in our universe started advancements in an inward direction rather than an outward direction in space. This concept can be compared to the miniaturization concept such as that of computers. Initially, computers were large in size but with the passage of time, their size decreased but power increased. Similarly, intelligent alien life progresses towards more denser and efficient use of space, time, energy, and matter, i.e. STEM. Eventually, the intelligent life in space started living in a black hole that is outside of this space-time continuum. Smart and other such researchers are of opinion that black holes are ideal for computation, energy generation, time travel, and more such processes for any kind of intelligent living beings.

Best place

Perhaps Earth is not a super-habitable place…

Science fiction often shows that intelligent alien life was searching for fuel or some other things such as food etc and they found Earth, but reality could be very different from that. May be Earth is not a super-habitable place in the universe. It is quite possible that if aliens are more intelligent than human beings they would not require the resources of Earth. They may think that the Earth and the living beings on this planet are of no use in regards to their highly advanced technologies. Moreover, if we leave the concept of super-habitable worlds, there are more than 8 billion Earth like planets in the universe, and intelligent aliens could go there, if they want.

Virtual Reality

Perhaps we are living in an artificial universe

Planetarium Hypothesis by Stephen Baxter suggests that we are perhaps living in an “artificial universe” or “virtual reality ‘planetarium’” that is giving us an illusion of empty universe. Supporters of this idea are also of opinion that we are living in a computer simulation that has been designed by some advanced aliens who are able to work on matter and energy on large scale. This is also showing that the intelligent life has not designed the program in such a way that we would be able to find any aliens in the universe.

Perhaps Earth is far far away from other inhabitable planets

Perhaps Earth is at a very large distance from other inhabited planets

Alien life might exist in the universe but still we have not met them, and one of the important reasons is that the Earth is at a very large distance away from them. In this case, Percolation theory suggests that some areas in the universe show large clustered growth, whereas some areas of growth have outlier positions. Other intelligent beings in the universe are perhaps living in that large clustered growth, and the Earth is in the outlier position.

Perhaps aliens have some unknown signals

We are unable to understand their signals

It is quite possible that alien life exists and they are also sending signals to us, but due to the difference in nature of signals we are unable to understand their signals. Perhaps, aliens have completely different senses as compared to human beings. Perhaps they are using the communication methods that are highly advanced in comparison to our communication methods.

As Lord Rees, cosmologist and astrophysicist, noted, “They could be staring us in the face, and we just don’t recognize them. The problem is that we’re looking for something very much like us, assuming that they at least have something like the same mathematics and technology. I suspect there could be life and intelligence out there in forms we can’t conceive.”

Via: John Smart, Montana State University, Robin Hanson, Planetarium Hypothesis, Percolation theory, Medea Hypothesis, ListVerse, Heller, R., & Armstrong, J. (2014). Superhabitable Worlds Astrobiology, 14 (1), 50-66 DOI: 10.1089/ast.2013.1088... Read more »

Heller, R., & Armstrong, J. (2014) Superhabitable Worlds. Astrobiology, 14(1), 50-66. DOI: 10.1089/ast.2013.1088  

  • December 20, 2016
  • 07:02 AM
  • 519 views

Diagnosing the Source Region of a Solar Burst on 26 September 2011 by Using Microwave Type-III Pairs by Tan B. L. et al.*

by CESRA in Solar Radio Science

Accelerated electron beams are believed to be responsible for both hard X-ray (HXR) and strong coherent radio emission during solar flares. However, so far the location of the electron acceleration and its physical parameters are poorly known. The solar microwave Type-III pair burst is possibly the most sensitive signature of [...]... Read more »

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