Astronomy posts

January 24, 2013
05:05 PM
293 views

Revolutionary theory of dark matter

The universe abounds with dark matter. Nobody knows what it consists of. UiO physicists have now launched a very hard mathematical explanation that could solve the mystery once and for all.

Astrophysicists have known for the last 80 years that most of the universe consists of an unknown, dark matter. The solution to the mystery may now be just around the corner.... Read more »

Yngve Vogt. (2013) Revolutionary theory of dark matter. Apollon Research Magazine University of Oslo. info:/

January 24, 2013
07:50 AM
147 views

Speed of the Gaseous remnants of the star GK Persei is not slowing down

by Usman Paracha in SayPeople

Astronomers have constructed the 3D model of the star GK Persei that blasted with a powerful explosion and found that its speed is not slowing down.

This research has been published online in The Astrophysical Journal.

Star GK Persei is located about 1,300 light years away from us. It is also referred to as Nova Persei 1901 as a strong thermonuclear eruption occurred on its surface on the 21st February 1901, the day when its brightness caused it to become one of the brightest stars in the sky.

Gaseous remaining materials of the star became visible in 1916.

"From then the visual spectacle has been similar to that of a firework display seen in slow motion," Miguel Santander, researcher at Spanish National Observatory and coauthor of the study, said in a statement.

Astronomers have developed 3D model of the remnant of a nova, i.e. remains of the star GK Persei after explosion, by utilizing the images captured from the Isaac Newton Telescope and the Nordic Optical Telescope in La Palma (Canary Islands, Spain). They gathered images, checked the movements and radial velocity of more than 200 knots using Doppler effect, which helps to check whether they are moving closer or further away from us.

"Such data are rarely available in astrophysics because as a general rule apparent expansion or, in other words, in the layout of the sky, the majority of objects cannot be seen," Romano Corradi, one of the authors of the study from the Astrophysics Institute of the Canary Islands, said.

Astronomers have found that the speed of the emitted gases didn’t slow down and is considered to be in the range of 600 km/s to 1,000 km/s even after more than 100 years.

All in all, this work shows "that the gas seems to be moving further away in a ballistic or free manner and is hardly slowing down, contrary to what was thought in previous studies," the lead author of the investigation, Tiina Liimets of the Tartu Observatory in Estonia, said.

Reference:

Liimets, T., Corradi, R., Santander-García, M., Villaver, E., Rodríguez-Gil, P., Verro, K., & Kolka, I. (2012). A THREE-DIMENSIONAL VIEW OF THE REMNANT OF NOVA PERSEI 1901 (GK Per) The Astrophysical Journal, 761 (1) DOI: 10.1088/0004-637X/761/1/34... Read more »

Liimets, T., Corradi, R., Santander-García, M., Villaver, E., Rodríguez-Gil, P., Verro, K., & Kolka, I. (2012) A THREE-DIMENSIONAL VIEW OF THE REMNANT OF NOVA PERSEI 1901 (GK Per). The Astrophysical Journal, 761(1), 34. DOI: 10.1088/0004-637X/761/1/34

Astronomy

January 21, 2013
10:29 AM
205 views

Martian Crater found to have groundwater activity in the past

by Usman Paracha in SayPeople

NASA's Mars Reconnaissance Orbiter (MRO) has found evidences of flowing lake in the McLaughlin Crater’s past.

This research has been published online in the journal Nature GeoScience.

McLaughlin crater, one of the deepest craters on Mars, is 57 miles across and 1.4 miles deep with apparent rocks of carbonate and clay minerals at the bottom that usually form in the presence of water.

Scientists found the minerals using the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on the Mars Reconnaissance Orbiter (MRO).

Although large inflow channels are not present in the McLaughlin lacks but small channels are found originating within the crater wall end at a level that could represent the surface of a lake.

These new findings show the production of the carbonates and clay in a groundwater-fed lake within the closed basin of the crater. According to some of the researchers, interior of the crater that catches the water and the underground zone that contributes to the water could have been wet environments and potential habitats.

"Taken together, the observations in McLaughlin Crater provide the best evidence for carbonate forming within a lake environment instead of being washed into a crater from outside," Joseph Michalski, lead author of the paper, which has five co-authors, said in a statement. Michalski also is affiliated with the Planetary Science Institute in Tucson, Ariz., and London's Natural History Museum.

"This new report and others are continuing to reveal a more complex Mars than previously appreciated, with at least some areas more likely to reveal signs of ancient life than others," says MRO project scientist Rich Zurek.

Reference:

Michalski, J., Cuadros, J., Niles, P., Parnell, J., Deanne Rogers, A., & Wright, S. (2013). Groundwater activity on Mars and implications for a deep biosphere Nature Geoscience DOI: 10.1038/ngeo1706... Read more »

Michalski, J., Cuadros, J., Niles, P., Parnell, J., Deanne Rogers, A., & Wright, S. (2013) Groundwater activity on Mars and implications for a deep biosphere. Nature Geoscience. DOI: 10.1038/ngeo1706

January 20, 2013
07:28 AM
232 views

Objects Beyond Cosmic Voids Not As Bright As They Appear

by Perikis Livas in Tracing Knowledge

(ISNS) — Giant cosmic voids that account for more than half the volume of the universe could make the stars beyond their boundaries appear brighter than they are, cosmologists have unexpectedly found.... Read more »

Charles Q. Choi. (2013) Objects Beyond Cosmic Voids Not As Bright As They Appear. Inside Science . info:/

January 15, 2013
04:40 PM
197 views

did the cosmological principle get knocked down?

by Greg Fish in weird things

Since the dawn of modern cosmology there’s been an implicit assumption that no particular spot in the universe was supposed to be any more special than the rest. On the biggest scales of all, scales at which galaxies are treated like tiny particles, the universe is supposed to be isotropic and homogeneous i.e. more or less uniform in composition and its expansion from the Big Bang. [...]... Read more »

Clowes, R., Harris, K., Raghunathan, S., Campusano, L., Sochting, I., & Graham, M. (2013) A structure in the early Universe at z 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology. Monthly Notices of the Royal Astronomical Society. DOI: 10.1093/mnras/sts497

January 14, 2013
01:57 AM
120 views

Venus Express flew over an electrical storm

by Paul Wren in Venus Dispatches

Christopher Russell has been looking for proof of lightning in the atmosphere of Venus for quite a while (his earliest publication I could find on the subject was in 1979). Now, Russell and his colleagues report on the strongest evidence yet for Venusian lightning (2012).In order to remove interference from magnetometer data collected previously by Venus Express, Russell and his team devised a new algorithm that uses the inboard sensor to detect interfering signals and then removes the same signals from the outboard sensor data, resulting in a "cleaned" signal covering the frequency rane from 0 to 64 Hz.Using the improved data collected during periapsis of the Venus Express spacecraft on April 15th of 2007, the researchers detected magnetic signals that led them to believe the craft had flown over an electrical storm.Of note are two very different signals the authors believe are associated with electrical activity in the atmosphere of Venus:1. a waveform that follows the prevailing magnetic field in the ionosphere and occurs at 20 Hz or above in the Extremely Low Frequency (ELF) range, and2. a second signal that occurs at Ultra-low (ULF) frequencies (and are thus not restricted to moving along the magnetic field) and which propagates upward through the atmosphere. The likely source is electrical activity beneath the spacecraft.In addition, the data revealed the presence of whistler waves (which would be expected if lightning were present), and is consistent with previous studies (Russell et al. 2007).Why is lightning on Venus important? Knowing it is there can help in comparative studies between Earth and Venus, but more importantly it can help assist in the understanding of the chemical processes at work in the Venusian atmosphere. The temperatures and pressures present in a lightning discharge provide a significant amount of energy that can drive chemical reactions, such as those that produce nitrous oxide. Lightning is a proposed energy source for the creation of amino acids on the primordial Earth, the building blocks of life.REFERENCESTaylor, W. W. L., Scarf, F. L., Russell, C. T., & Brace, L. H. (1979). Evidence for lightning on venus. Nature, 279, 614-616. Russell, C., Zhang, T., Delva, M., Magnes, W., Strangeway, R., & Wei, H. (2007). Lightning on venus inferred from whistler-mode waves in the ionosphere. Nature, 450(7170), 661-662. Russell, C., Leinweber, H., Zhang, T., Daniels, J., Strangeway, R., & Wei, H. (2012). Electromagnetic waves observed on a flight over a Venus electrical storm Geophysical Research Letters DOI: 10.1029/2012GL054308 ... Read more »

Russell, C., Leinweber, H., Zhang, T., Daniels, J., Strangeway, R., & Wei, H. (2012) Electromagnetic waves observed on a flight over a Venus electrical storm. Geophysical Research Letters. DOI: 10.1029/2012GL054308

January 13, 2013
05:46 PM
82 views

Variations in sulphur dioxide at the cloud tops of Venus: due to volcanoes? maybe not

by Paul Wren in Venus Dispatches

A recent article in Nature Geoscience, Variations of sulphur dioxide at the cloud top of Venus's dynamic atmosphere, has caused the science press to get excited about the possibility of active volcanoes on Venus.Every news headline I saw over the last few weeks that referred to this article wondered aloud if there are active volcanoes. Even the ESA website poses the news as a question. So, does Venus have active volcanism? First, let's talk about the paper and what it reports.Emmanuel Marcq and colleagues used ultraviolet spectrometer data collected from 2007 to 2012 using the SPICAV instrument aboard the Venus Express spacecraft to examine the density of sulphur dioxide above the clouds of Venus. They found that SO2 column densities increased prior to 2007, and then decreased by a factor of 5 over the next five years.This finding is quite similar to observations made by the Pioneer Venus Orbiter in the 1970s and 1980s, which revealed a ten-fold decrease in SO2 column density. At the time, Larry Esposito (1984) of the Laboratory for Atmospheric and Space Physics in Boulder interpreted this decline to have occurred following an episode of volcanogenic upwelling from the lower atmosphere (it is important to note that SO2 is abundant and ubiquitous in the lower atmosphere of Venus).Marcq, et al. conclude that the SO2 variability observed from the 1970s to the present is the result of long-timescale fluctuations in upward transport from the troposphere to the mesosphere.What they do not know is whether this is the result of 1) episodic increased buoyancy from volcanic plumes, or 2) intrinsic dynamic variability in the upward component of the global circulation.Back to our original question: Does Venus possess active volcanoes? This study cannot answer that question. The authors seem to want it to be so, but say in their conclusion: "By Occam's razor, we are inclined to think that this variability originates from intrinsic dynamical variability in the ascending sub-solar branch of the global circulation at cloud-top level on a decennial timescale rather than from an external forcing such as extra buoyancy caused by volcanic eruptions, but we cannot dismiss a volcanic forcing through our study alone."It's pretty clear that most people want active volcanoes on Venus, but the jury is still out, I'm afraid.REFERENCES:Esposito, L. W. (1984). Sulfur dioxide: Episodic injection shows evidence for active venus volcanism. Science (New York, N.Y.), 223(4640), 1072-1074. doi: 10.1126/science.223.4640.1072 Marcq, E., Bertaux, J., Montmessin, F., & Belyaev, D. (2012). Variations of sulphur dioxide at the cloud top of Venus’s dynamic atmosphere Nature Geoscience DOI: 10.1038/NGEO1650... Read more »

Marcq, E., Bertaux, J., Montmessin, F., & Belyaev, D. (2012) Variations of sulphur dioxide at the cloud top of Venus’s dynamic atmosphere. Nature Geoscience. DOI: 10.1038/NGEO1650

January 12, 2013
04:32 AM
186 views

Oldest known star in the Universe

by Usman Paracha in SayPeople

Astronomers have probably found the oldest star of the universe, i.e. nearly 13.2 billion years old, and interestingly it is located near to our Solar System.

“We believe this star is the oldest known in the Universe with a well determined age,” Howard Bond, an astronomer at Pennsylvania State University in University Park, who presented the finding on 10th of January at a meeting of the American Astronomical Society in Long Beach, California, said in a statement.

This proposed oldest star is referred to as HD 140283 and is located at a distance of approximately 190 light years from us. It is known by the astronomers for more than a century. Researchers already knew that the object is almost entirely made up of hydrogen and helium showing that the star was from the early universe but the exact age of the star was not known.

Bond and the team members, firstly, determine the more accurate distance of the star from the Solar System with the help of 11 sets of observations recorded between 2003 and 2011 using the Hubble Space Telescope’s Fine Guidance Sensors. They then determine the brightness of the star and calculate its intrinsic brightness as the stars’ dimming brightness is always a very good indicator of their age.

Astronomers found that the star is in such phase of its life cycle in which it is draining the hydrogen at its core. They calculated the age of the star to be 13.9 ± 0.7 billion years old. Consider that this age, in the minus side i.e. 13.2 billion years, is not conflicting with the age of the universe i.e. 13.77 billion years.

The age of this star is known with more confidence than the previously known oldest star, HE 1523-0901, said Bond. HE 1523-0901 is also present in our Milky Way galaxy.

Source: Cowen, R. (2013). Nearby star is almost as old as the Universe Nature DOI: 10.1038/nature.2013.12196... Read more »

Cowen, R. (2013) Nearby star is almost as old as the Universe. Nature. DOI: 10.1038/nature.2013.12196

Astronomy

January 11, 2013
11:14 AM
301 views

Astronomers identify structure so huge it disrupts cosmic uniformity

by Perikis Livas in Tracing Knowledge

Astronomers have found a clump of bright galaxies so huge, it jolts their longstanding belief that the universe is pretty uniform on large scales.

And the scientists warn that more such discoveries may be on the way.... Read more »

Royal Astronomical Society, & World Science staff. (2013) Astronomers identify structure so huge it disrupts cosmic uniformity. World Science. info:/

January 11, 2013
08:57 AM
260 views

Largest object in the Universe ever found

by Usman Paracha in SayPeople

Astronomers have found the largest known structure in the universe, i.e. a clump of active galactic cores, ranging in the size of 4 billion light years from one end to another at its widest point.

This research has been published online in the Monthly Notices of the Royal Astronomical Society.

This largest ever found object is a large quasar group (LQG) that is made up of extremely shining nuclei powered by supermassive central black holes.

Quasars are the high-energy and compact astronomical objects in the universe. They show a large red shift representing their extreme remoteness in the space. Their energy is so large that sometimes the energy is equal to the output of an entire galaxy.

This record-breaking quasar group is composed of 73 quasars and spans to about 1.6 billion light-years in most directions with 4 billion light-years on the widest side i.e. slightly less than one third of the size of the universe according to the present calculations.

"While it is difficult to fathom the scale of this LQG, we can say quite definitely it is the largest structure ever seen in the entire universe," lead author Roger Clowes, of the University of Central Lancashire in England, said in a statement. "This is hugely exciting, not least because it runs counter to our current understanding of the scale of the universe."

According to researchers, the size of this particular group of celestial body challenges modern cosmological theory, which points to the homogenous universe when viewed at a sufficiently large scale. Theoretical calculations negate the presence of structures larger than 1.2 billion light-years. So the theory predicts that the LQC shouldn’t be there.

"Our team has been looking at similar cases which add further weight to this challenge, and we will be continuing to investigate these fascinating phenomena," Clowes said.

Reference:

Roger G. Clowes, Kathryn A. Harris, Srinivasan Raghunathan, Luis E. Campusano, Ilona K. Soechting, & Matthew J. Graham (2012). A structure in the early universe at z ~ 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology Monthly Notices of the Royal Astronomical Society arXiv: 1211.6256v1... Read more »

Roger G. Clowes, Kathryn A. Harris, Srinivasan Raghunathan, Luis E. Campusano, Ilona K. Soechting, & Matthew J. Graham. (2012) A structure in the early universe at z ~ 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology. Monthly Notices of the Royal Astronomical Society. arXiv: 1211.6256v1

Astronomy

January 10, 2013
05:00 PM
187 views

why alien moons might just be teeming with life

by Greg Fish in weird things

Another day, another study identifying more potentially habitable worlds in the Kepler data, this time by professional astronomers and volunteers called the Planet Hunters who discussed their planet detections on a specialized message board system called Talk. What they found was that more gas giants orbited stars in their habitable zones than initially thought, giving real evidence for the hypothesis that while alien Earths could be somewhat rare, moons orbiting alien Jupiters and Saturns may be a fairly common habitat for extraterrestrial life. [...]... Read more »

Ji Wang, Debra A. Fischer, Thomas Barclay, Tabetha S. Boyajian, Justin R. Crepp, Megan E. Schwamb, Chris Lintott, Kian J. Jek, Arfon M. Smith, Michael Parrish.... (2013) Planet Hunters. V. A Confirmed Jupiter-Size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data. n/a. arXiv: 1301.0644v1

January 7, 2013
12:49 PM
186 views

15 new planets have been discovered that can support life

by Usman Paracha in SayPeople

Fifteen new planets have been discovered in the habitable zones of the other stars.

A report of the research has been submitted to the Astrophysical Journal and released via arxiv.org on Monday 7 January 2013.

This research has been done by the participants from the Planethunters.org website that is the part of the Oxford University based Zooniverse project.

This discovery has added the planets to the already discovered 19 planets in the habitable zones. These planets are in the habitable zones and are considered as neither too hot nor too cold for the presence of liquid water. This new finding proposes a kind of 'traffic jam' of all kinds of strange worlds in areas that could seriously support life.

One of the 15 planets, dubbed as 'PH2 b', is about the size of Jupiter and is orbiting a Sun-like star has been officially confirmed as a planet with certainty of 99.9% after follow up work of Keck telescope in Hawai'i.

“There's an obsession with finding Earth-like planets but what we are discovering, with planets such as PH2 b, is far stranger,” Zooniverse lead Dr Chris Lintott of Oxford University, said in a statement. “Jupiter has several large water-rich moons - imagine dragging that system into the comfortably warm region where the Earth is. If such a planet had Earth size moons, we'd see not Europa and Callisto but worlds with rivers, lakes and all sorts of habitats - a surprising scenario that might just be common.”

“We are seeing the emergence of a new era in the Planet Hunters project where our volunteers seem to be at least as efficient as the computer algorithms at finding planets orbiting at habitable zone distances from the host stars," said Planethunters lead scientist Professor Debra Fisher of Yale University. "Now, the hunt is not just targeting any old exoplanet - volunteers are homing in on habitable worlds.”

Lead author Dr Ji Wang, also of Yale University, said, “We can speculate that PH2 b might have a rocky moon that would be suitable for life. I can't wait for the day when astronomers report detecting signs of life on other worlds instead of just locating potentially habitable environments. That could happen any day now.”

“These are planet candidates that slipped through the net, being missed by professional astronomers and rescued by volunteers in front of their web browsers," said Lintott." It's remarkable to think that absolutely anyone can discover a planet.”

“In general, we have shown that we are not quite as unique as we once thought. Our solar system closely resembles other observable planetary systems within our galaxy. In this way, our results serve to corroborate other research results which indicate that earth-like planets are more widespread in the universe than previously believed,” said Professor Martin Bizzarro, head of the Centre for Star and Planet Formation at University of Copenhagen.

From the Planet Hunters, “Although most of these planets are large, like Neptune or Jupiter in our own Solar System, these discoveries increase the sample size of long-period planet candidates by more than 30% and almost double the number of known gas giant planet candidates in the habitable zone. In the future, we may find moons around these planet candidates (just like Pandora around Polyphemus in the movie Avatar) that allows life to survive and evolve under a habitable temperature.”

Reference:

Ji Wang, Debra A. Fischer, Thomas Barclay, Tabetha S. Boyajian, Justin R. Crepp, Megan E. Schwamb, Chris Lintott, Kian J. Jek, Arfon M. Smith, Michael Parrish, Kevin Schawinski, Joseph Schmitt, Matthew J. Giguere, John M. Brewer, Stuart Lynn, Robert Simpson, Abe J. Hoekstra, Thomas Lee Jacobs, Daryll LaCourse, Hans Martin Schwengeler, & Mike Chopin (2013). Planet Hunters. V. A Confirmed Jupiter-Size Planet in the Habitable Zone
and 42 Planet Candidates from the Kepler Archive Data Astrophysical Journal arXiv: 1301.0644v1... Read more »

Ji Wang, Debra A. Fischer, Thomas Barclay, Tabetha S. Boyajian, Justin R. Crepp, Megan E. Schwamb, Chris Lintott, Kian J. Jek, Arfon M. Smith, Michael Parrish.... (2013) Planet Hunters. V. A Confirmed Jupiter-Size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data. Astrophysical Journal . arXiv: 1301.0644v1

Astronomy

January 6, 2013
07:47 PM
190 views

Two stars in the sky of the exoplanets are not that pleasant

by Usman Paracha in SayPeople

Researchers have found that the planets in the two star systems have more chances to move out into the interstellar space.

This research has been published online in the journal Nature.

Researchers have found that this effect is usually limited to the planetary systems with at least one distantly orbiting object while the stellar fellows with closer orbits have fewer chances of violent disturbances.

"The fact that planets observed within wide binaries tend to have more eccentric (or 'excited') orbits than those around isolated stars tells us that wide binaries do often disrupt planetary systems," lead author Nathan Kaib, of Northwestern University and the University of Toronto, told SPACE.com via email.

"Thus, we believe most planetary systems are extended, with outer planets orbiting at tens of AU from their host stars," Kaib added. (One AU, or astronomical unit is nearly 93 million miles, or 150 million kilometers i.e. the distance from Earth to the sun).

Binary star systems, in which two stars are revolving around one another, are as common in our galaxy as the single stars. Recently, scientists have found planets in those binary star systems presenting two stars in the sky of those planets. In those, many of the systems are wide binaries i.e. the distance between the stars is 1000 AU or more, and the orbits of those circulating bodies change with time due to their distance from each other.

"The stellar orbits of wide binaries are very sensitive to disturbances from other passing stars as well as the tidal field of the Milky Way," Kaib said in a statement. "This causes their stellar orbits to constantly change their eccentricity, their degree of circularity. If a wide binary lasts long enough, it eventually will find itself with a very high orbital eccentricity at some point in its life.”

Researchers performed nearly 3,000 computer simulations and found that the eccentric orbits could bring the two stars quite close together resulting in huge disturbances to the orbits of the planets in those systems. In a series of computer simulations, researchers added a wide-binary companion to our own solar system and found that at least one giant planet, i.e. Jupiter, Saturn, Uranus or Neptune, ejected into the space in half of those simulations.

"This process takes hundreds of millions of years if not billions of years to occur in these binaries. Consequently, planets in these systems initially form and evolve as if they orbited an isolated star," said Kaib, who will present the findings this week at the 221st meeting of the American Astronomical Society in Long Beach, California. "It is only much later that they begin to feel the effects of their companion star, which often times leads to disruption of the planetary system."

Researchers have also found that the planetary ejection is not always the result of such destabilization but the exoplanets could be moved from the near circular orbits to the more eccentric orbits.

"We also found that there is substantial evidence that this process occurs regularly in known extrasolar planetary systems," Queen's University physics professor Martin Duncan, said. "Planets are believed to form on circular orbits, and they are only thought to attain highly eccentric orbits through powerful and/or violent perturbations. When we looked at the orbital eccentricities of planets that are known to reside in wide binaries, we found that they are statistically more eccentric than planets around isolated stars like our Sun. "

Simulations also showed that such disturbances occur only in the planets that are 10 AU or so from the host star.

"Given that most planet-detection campaigns cannot detect planets beyond 5-10 AU from their host stars, our results provide new clues about the characteristics of planetary systems in a regime that is poorly constrained by current observations," Kaib told SPACE.com. "We believe that planets orbiting at distances of 10 AU or further from their host stars are common."

Researchers wrote, ‘Consequently, our results suggest that although wide binaries eventually remove the most distant planets from many planetary systems, most isolated giant exoplanet systems harbour additional distant, still undetected planets.”

Reference:

Kaib, N., Raymond, S., & Duncan, M. (2013). Planetary system disruption by Galactic perturbations to wide binary stars Nature DOI: 10.1038/nature11780... Read more »

Kaib, N., Raymond, S., & Duncan, M. (2013) Planetary system disruption by Galactic perturbations to wide binary stars. Nature. DOI: 10.1038/nature11780

January 6, 2013
10:13 AM
271 views

Plumbing the depths: the search for water in our solar system and beyond

by Perikis Livas in Tracing Knowledge

Earth is the only planet in our solar system with a long-term, stable supply of liquid water – essential for the formation and evolution of all organic life. But this doesn’t mean there aren’t other pockets of water elsewhere in our solar system (and around other stars).... Read more »

Lucyna Kedziora-Chudczer. (2012) Plumbing the depths: the search for water in our solar system and beyond. UNSW News. info:/

January 6, 2013
05:55 AM
263 views

Carbon in Vesta’s craters

by Perikis Livas in Tracing Knowledge

The protoplanet Vesta has been witness to an eventful past: images taken by the framing camera onboard NASA’s space probe Dawn show two enormous craters in the southern hemisphere. The images were obtained during Dawn’s year-long visit to Vesta that ended in September 2012. These huge impacts not only altered Vesta’s shape, but also its surface composition. Scientists under the lead of the Max Planck Institute for Solar System Research in Katlenburg-Lindau in Germany have shown that impacting small asteroids delivered dark, carbonaceous material to the protoplanet. In the early days of our solar system, similar events may have provided the inner planets such as Earth with carbon, an essential building block for organic molecules.... Read more »

Max Planck Institute. (2013) Carbon in Vesta's craters. Max Planck Institute Astronomy News. info:/

January 4, 2013
11:43 AM
219 views

The Science of Choosing Space Pioneers

by Jason Carr in Wired Cosmos

I often ask others if they would live in space or on another planet if given the opportunity. More often than not, the answer is in the affirmative. But what if you were given the chance and actually wanted to go, but were declined because you weren’t selected by a computer algorithm as one of [...]... Read more »

Yusof, N., & van Loon, J. (2012) Engineering a Global City: The Case of Cyberjaya. Space and Culture, 15(4), 298-316. DOI: 10.1177/1206331212453676

Saaty, T., & Sagir, M. (2012) Global awareness, future city design and decision making. Journal of Systems Science and Systems Engineering, 21(3), 337-355. DOI: 10.1007/s11518-012-5196-z

January 3, 2013
04:37 PM
240 views

ALMA Shows How Young Star and Planets Grow Simultaneously

by Perikis Livas in Tracing Knowledge

Astronomers have used the ALMA telescope to get their first glimpse of a fascinating stage of star formation in which planets forming around a young star are helping the star itself continue to grow, resolving a longstanding mystery. The young system, about 450 light-years from Earth, is revealing its complex gravitational dance to the ever-sharpening vision of the Atacama Large Millimeter/submillimeter Array (ALMA), scheduled for completion this year.... Read more »

Dave Finley. (2013) ALMA Shows How Young Star and Planets Grow Simultaneously. National Radio Astronomy Observatory News. info:/

January 2, 2013
12:07 PM
177 views

Magnetic forces without magnets before the creation of first stars in the universe

by Usman Paracha in SayPeople

Magnetic fields of weaker strength, than the present day Earth’s magnetic field, were created even before the development of the first stars.

This recent research has been done by Prof. Dr. Reinhard Schlickeiser at the Institute of Theoretical Physics of the Ruhr-Universität Bochum and published online in the journal of Physical Review Letters.

This research shows the mechanism through which the magnetic forces came into being before the first stars, when according to the present knowledge, the universe was consisted only of nonmagnetic elements and particles.

Shining objects, before the formation of the first stars, consisted only of fully ionised gas of protons, electrons, helium nuclei and lithium nuclei developed during the Big Bang. “All higher metals, for example, magnetic iron could, according to today’s conception, only be formed in the inside of stars”, Reinhard Schlickeiser, said in a statement. “In early times therefore, there were no permanent magnets in the Universe.”

Parameters describing the state of the gas such as density, pressure, electric and magnetic fields vary around certain mean values. As a result of these variations in the plasma, weak magnetic fields are formed, which are referred to as random fields. In this research, Prof. Schlickeiser calculated the strength of the fields in fully ionized plasma of protons and electrons especially for the gas densities and temperatures that occurred in the plasmas of the early universe.

It has been found that the magnetic field varies with the position in the plasma.

A strength of 10-20 Tesla, i.e. 10 sextillionth of a Tesla, has been calculated in the luminous gas of the early universe that is very weak as for comparison Earth’s magnetic field has a strength of 30 millionths of a Tesla. Although the early magnetic field was very weak but it was sufficient to cover almost every part of the plasma volume.

Those fields were strengthened and aligned on a wide-scale as a result of the shock waves generated by the stellar winds or supernova explosions of the first huge stars. The strength of the magnetic forces ultimately became so strong that they started affecting the shock waves finally.

“This explains the balance often observed between magnetic forces and thermal gas pressure in cosmic objects”, says Prof. Schlickeiser.

This research shows that the fully ionized gases in the early universe had weak magnetic fields.

Reference:

Schlickeiser, R. (2012). Cosmic Magnetization: From Spontaneously Emitted Aperiodic Turbulent to Ordered Equipartition Fields Physical Review Letters, 109 (26) DOI: 10.1103/PhysRevLett.109.261101... Read more »

Schlickeiser, R. (2012) Cosmic Magnetization: From Spontaneously Emitted Aperiodic Turbulent to Ordered Equipartition Fields. Physical Review Letters, 109(26). DOI: 10.1103/PhysRevLett.109.261101

January 1, 2013
02:27 PM
215 views

Reaching E.T. Through Standardized Protocols

by Jason Carr in Wired Cosmos

Choosing a single telecommunications protocol has always been difficult for engineers on Earth, so it’s especially difficult for those who want to communicate with beings from another star system. While it’s nice to imagine that extraterrestrial beings would be able to interface with whatever protocol humans decide to encode a message in, that’s not a [...]... Read more »

Atri, D., DeMarines, J., & Haqq-Misra, J. (2011) A protocol for messaging to extraterrestrial intelligence. Space Policy, 27(3), 165-169. DOI: 10.1016/j.spacepol.2011.01.001

Edmondson, W. (2010) Targets and SETI: Shared motivations, life signatures and asymmetric SETI. Acta Astronautica, 67(11-12), 1410-1418. DOI: 10.1016/j.actaastro.2010.01.017

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