News from Space: Mysterious Radio Waves Detected…

auriga_nebulaAccording to a story published on July 10 in The Astrophysical Journal, a radio burst was detected that may have originated outside of our galaxy. Apparently, these split-second radio bursts have heard before, but always with the same telescope – Parkes Observatory in Australia. Given that only this observatory was detecting these signals, there was debate about whether they were coming from inside our galaxy, or even from Earth itself.

However, this time the radio signals were detected by a different telescope – the Arecibo Observatory in Puerto Rico – which concluded that the bursts are coming from outside the galaxy. This is also the first time one of these bursts have been found in the northern hemisphere of the sky. Exactly what may be causing such radio bursts represents a major new enigma for astrophysicists.

Victoria Kaspi, an astrophysics researcher at McGill University who participated in the research, explained:

Our result is important because it eliminates any doubt that these radio bursts are truly of cosmic origin. The radio waves show every sign of having come from far outside our galaxy – a really exciting prospect.

arecibo_arrayFast radio bursts are a flurry of radio waves that last a few thousandths of a second, and at any given minute there are only seven of these in the sky on average, according to the Max Planck Institute for Radio Astronomy. Their cause is unknown, and the possibilities range from black holes, to neutron stars coming together, to the magnetic field of pulsars (a type of neutron star) flaring up.

The pulse was detected on Nov. 2, 2012, at the Arecibo Observatory – a National Science Foundation-sponsored facility that has the world’s largest and most sensitive radio telescope. While fast radio bursts last just a few thousandths of a second and have rarely been detected, the international team of scientists reporting the Arecibo finding estimate that these bursts occur roughly 10,000 times a day over the whole sky.

MaxPlanckIns_radiowavepulseThis astonishingly large number is inferred by calculating how much sky was observed, and for how long, in order to make the few detections that have so far been reported. Laura Spitler, a postdoctoral researcher at the Max Planck Institute for Radio Astronomy in Bonn, Germany and the lead author of the new paper, was also the first person to note the event. As she explained:

The brightness and duration of this event, and the inferred rate at which these bursts occur, are all consistent with the properties of the bursts previously detected by the Parkes telescope in Australia.

The bursts appear to be coming from beyond the Milky Way, based on measurement of an effect known as plasma dispersion. Pulses that travel through the cosmos are distinguished from man-made ones by the effect of interstellar electrons, which cause radio waves to travel more slowly at lower radio frequencies. The burst detected by the Arecibo telescope has three times the maximum dispersion measure that would be expected from a local source.

Four_antennas_ALMAEfforts are now under way to detect radio bursts using radio telescopes that can observe broad swaths of the sky to help identify them. Telescopes under construction in Australia and South Africa as well as the CHIME telescope in Canada have the potential to detect fast radio bursts. Astronomers say these and other new facilities could pave the way for many more discoveries and a better understanding of this mysterious cosmic phenomenon.

For those hoping this was a possible resolution to the Fermi Paradox – i.e. that the radio bursts might have been extra-terrestrial in origin – this news is a little disappointing. But in truth, its yet another example of the deeper mysteries of the universe at work. Much like our ongoing research into the world of elementary particles, every answer gives rise to new questions.

Sources: universetoday.com, kurzweilai.net

News From Space: Alpha Centauri’s “Superhabitable” World

alpha_centauri_newsScientists and astronomers have learned a great deal about the universe in recent years, thanks to craft like the Kepler space probe and the recently launched Gaian space observatory. As these and other instruments look out into the universe and uncover stars and exoplanets, it not only lets us expand our knowledge of the universe, but gives us a chance to reflect upon the meaning of this thing we call “habitability”.

Basically, our notions of what constitutes a habitable environment are shaped by our own. Since Earth is a life-sustaining environment from which we originated, we tend to think that conditions on another life-giving planet would have to be similar. However, scientists René Heller and John Armstrong contend that there might be a planet even more suitable in this galaxy, and in the neighboring system of Alpha Centauri B.

alpha_centauriBb1For those unfamiliar, Alpha Centauri A/B is a triple star system some 4.3 light years away from Earth, making it the closest star system to Earth. The nice thing about having a hypothetical “superhabitable” planet in this system is that it makes it a lot easier to indulge in a bit of a thought experiment, and will make it that much more easy to observe and examine.

According to the arguments put forward by Heller, of the Department of Physics and Astronomy, McMaster University, Hamilton; and Armstrong, of the Department of Physics, Weber State University in Ogden, this planet may be even more suitable for supporting life than our own. It all comes down to meeting the particulars, and maybe even exceeding them.

habitable_sunsFor example, a habitable planet needs the right kind sun – one that has existed and remained stable for a long time. If the sun in question is too large, then it will have a very short life; and if it’s too small, it might last a long time. But the planet will have to be very close to stay warm and that can cause all sorts of problems, such as a tidally locked planet with one side constantly facing the sun.

Our own sun is a G2-type star, which means it has been alive and stable for roughly 4.6 billion years. However, K-type dwarfs, which are smaller than the Sun, have lives longer than the age of the universe. Alpha Centauri B is specifically a K1V-type star that fits the bill with an estimated age of between 4.85 and 8.9 billion years, and is already known to have an Earth-like planet called Alpha Centauri B b.

alpha_centauriBb2As to the superhabitable planet, assuming it exists, it will be located somewhere between 0.5 and 1.4 astronomical units (46 – 130 million mi, 75 – 209 million km) from Alpha Centauri B. All things being equal, it will have a circular orbit 1. 85 AU (276 million km / 172 million miles) away, which would place it in the middle of the star’s habitable zone.

Also, for a planet to sustain life it has to be geologically active, meaning it has to have a rotating molten core to generate a magnetic field to ward off cosmic radiation and protect the atmosphere from being stripped away by solar winds. A slightly more massive planet with more gravity means more tectonic activity, so a better magnetic field and a more stable climate.

 

PlutoHowever, the most striking difference between the superhabitable world and Earth would be that the former would lack our continents and deep oceans – both of which can be hostile to life. Instead, Heller and Armstrong see a world with less water than ours, which would help to avoid both a runaway greenhouse effect and a snowball planet that an overabundance of water can trigger.

Our superhabitable planet might not even be in the habitable zone. It could be a moon of some giant planet further away. Jupiter’s moon Io is a volcanic hellhole due to tidal heating, but a larger moon that Heller and Armstrong call a “Super Europa” in the right orbit around a gas giant could heat enough to support life even if it’s technically outside the star’s habitable zone.

 

alien-worldAccording to Heller and Armstrong, this world would look significantly different from our own. It would be an older world, larger and more rugged, and would provide more places for life to exist. What water there was would be evenly scattered across the surface in the form of lakes and small, shallow seas. And, it would also be slightly more massive, which would mean more gravity.

This way, the shallow waters would hold much larger populations of more diverse life than is found on Earth, while the temperatures would be more moderated. However, it would be a warmer world than Earth, which also makes for more diversity and potentially more oxygen, which the higher gravity would help with by allowing the planet to better retain its atmosphere.

panspermia1Another point made by Heller and Armstrong is that there may be more than one habitable planet in the Alpha Centauri B system. Cosmic bombardments early in the history of the Solar System is how the Earth got its water and minerals. If life had already emerged on one planet in the early history of the Alpha Centauri B system, then the bombardment might have spread it to other worlds.

But of course, this is all theoretical. Such a planet may or may not exist, and may or may not have triggered the emergence of life on other worlds within the system. But what is exciting about it is just how plausible its existence may prove to be, and how easy it will be to verify once we can get some space probes between here and there.

Just imagine the sheer awesomeness of being able to see it, the images of a super-sized Earth-moon beamed back across light years, letting us know that there is indeed life on worlds besides our own. Now imagine being able to study that life and learning that our conceptions of this too have been limited. What a time that will be! I hope we all live to see it…

 

 

Sources: gizmag.com, universetoday.com

The Future is Weird: Cyborg Sperm!

cyborg_sperm1Finding ways to merge the biological and the technological, thus creating the best of both worlds, is one of the hallmarks of our new age. Already, we have seen how bionic appendages that connect and calibrate to people’s nerve signals can restore mobility and sensation to injured patients. And EEG devices that can read and interpret brainwaves are allowing man-machine interface like never before.

But cyborg sperm? That is something that might require an explanation. You see, sperm cells have an awesome swimming ability. And wanting to take advantage of this, Oliver Schmidt and a team researchers at the Institute for Integrative Nanosciences in Dresden, Germany, combined individual sperm cells with tiny magnetic metal tubes to create the first sperm-based biobots.

Cyborg_Sperm3This means we now have a way to control a cell’s direction inside the body, a breakthrough that could lead to efficient microscopic robots – one which are not entirely mechanical. To make the “biohybrid micro-robot,” Schmidt and his colleagues captured and trapped bull sperm inside magnetic microtubes, leaving the tail outside.

To create the spermbots, the team made microtubes 50 microns long, by 5 to 8 microns in diameter from iron and titanium nanoparticles. They added the tubes to a fluid containing thawed bull sperm. Because one end of each tube was slightly narrower than the other, sperm that swam into the wider end become trapped, headfirst, with their flagella still free.

cyborg_sperm2With mobility taken care of, the team moved on to the matter of how to control and direct the microtubes. For this, they chose to rely on a system of external magnetic fields which work the same way as a compass needle does, by aligning with the Earth’s magnetic field. This enabled the team to control the direction in which the sperm swam, adjusting their speed through the application of heat.

According to the researchers, the option of using sperm as the basis for a biohybrid micro-robot is attractive because they are harmless to the human body, they provide their own power, and they can swim through viscous liquids – such as blood and other bodily fluids. As the researchers said in their paper:

The combination of a biological power source and a microdevice is a compelling approach to the development of new microrobotic devices with fascinating future application.

cyborg_spermGranted, the idea of cybernetic sperm swimming through our systems might not seem too appealing. But think of the benefits for fertility treatments and inter-uteran health. In the future, tiny biohybrid robots like these could be used to shepherd individual sperm to eggs, making for more effective artificial insemination. They could also  deliver targeted doses of drugs to uteran tissue that is either infected or cancerous.

And if nothing else, it helps to demonstrate the leaps and bounds that are being made in the field of  biotechnology and nanotechnology of late. At its current rate of development, we could be seeing advanced medimachines and DNA-based nanobots becoming a part of regular medical procedures in just a few years time.

And while we’re waiting, check out this video of the “cyborg sperm” in action, courtesy of New Scientist:


Sources:
IO9, newscientist.com

News from Space: The Search for Life on Europa

europa-landerJupiter’s moon of Europa is one of the best and most intriguing candidates for extra-terrestrial life in our Solar System. For many decades, scientists have known that beneath its icy outer-shell, a warm, liquid ocean resides. Due largely to interaction with Jupiter’s strong magnetic field – which causes heat-generating tidal forces in Europa’s interior – these warm waters may host life.

And now, new models suggest that its ice-covered waters are turbulent near the lower latitudes. This is what gives rise to its chaotic equatorial landscapes, but intriguingly, may also make it easier for life to make it to the surface. This contradicts previously held beliefs that Europa’s life was contained beneath it’s outer shell, and will mean that any missions mounted to Europa may have an easier time spotting it.

europa_chaosterrainThanks to ongoing observation of the planet’s surface – especially the Galileo and New Horizons space probes which provided comprehensive and detailed images – it has been known that Europa’s surface features are not consistent. The landscape is marked by features of disrupted ice known as chaos terrains, geological features that are characterized by huge chunks of ice that have broken away and then re-froze into chaotic patterns.

These models were produced by University of Texas geophysicist Krista Soderlund and her colleagues. Based on computer simulations, Soderlund and her colleagues have theorized that turbulent global ocean currents move Europa’s internal heat to the surface most efficiently in regions closest to the moon’s equator. This is likely causing the melting and upwelling at the surface, and why regions further north and south appear to be smoother.

europa_modelIn addition, the models indicate that given Europa’s spin, heat flow, and other factors, it likely percolates upward at about 1m per second or so — which is remarkably fast. This would explain why the equatorial regions appear to be so fragmented. But it also means that these areas are also likely yo be relatively fragile and soft, which means that upward currents could bring nutrients and even living organisms to the surface.

Hence why any potential search for signs of life on this moon would now appear to be considerably easier. If missions are indeed mounted to Europa in the not-too-distant future, either involving probes or manned missions (most likely in that order), their best bet for finding life would be to land at the equator. Then, with some drilling, they could obtain core samples that would determine whether or not life-sustaining nutrients and organic particles exist beneath the ice.

Hopefully, these missions won’t run afoul of any life that doesn’t take too well to their presence. We don’t want a re-enactment of Europa Report on our hands now do we?

Source: IO9.com

Apocalypse News: Sun’s Magnetive Field about to Flip

sun_magneticfieldThe sun is set to reverse its polarity in the next few months, something that occurs at the height of every Solar Cycle. The resulting ripple effect will be felt all across the Solar System and will even be detectable by the far-away Voyager probes. However, scientists are telling us not to fret, as this event will not lead to the end of the world.

In truth, the Sun’s reversal of polarity is something that occurs every 11 years. And the shift won’t spark an increase in powerful solar storms or other events that could have a damaging effect on Earth and its inhabitants, say the researchers. One such researcher is Phil Scherrer, a solar physicist at Stanford University, who insisted “The world will not end tomorrow.”

NASAsolar_radiationIn addition, from a human perspective, the effects of the field shift will likely be slight and even beneficial. For example, the polarity reversal will cause the “current sheet” – an enormous surface extending out from the solar equator on which the sun’s rotating magnetic field has induced an electric current – to become much wavier.

This crinkled current sheet, in turn, will provide a better barrier against galactic cosmic rays, high-energy particles that are accelerated to nearly the speed of light by faraway star explosions. Galactic cosmic rays can damage spacecraft and hurt orbiting astronauts who don’t get to enjoy the protection of Earth’s thick atmosphere. So for space exploration, at any rate, this is certainly good news.

Sun's Heliospheric-current-sheetAccording to Todd Hoeksema, director of Stanford’s Wilcox Observatory, a drop in galactic cosmic ray levels could also have a subtle impact on weather here on Earth.

One of the things that helps clouds form and lightning to flash is cosmic-ray ionization of things in the Earth’s atmosphere. So when the cosmic-ray intensity is lower, it means you have fewer places where lightning will occur, and so the storms will probably be a little less intense.

He added, however, that it’s pretty much a speculative endeavor at this point, as no conclusive link has ever been demonstrated between cosmic rays and the weather.

In any case, during a reversal, the sun’s polar magnetic fields weaken all the way down to zero, then bounce back with the opposite polarity. Researchers will keep a keen eye on just how strong this recovery is over the next two years or so. The sun has been quiet during its current 11-year activity cycle, which is known as Solar Cycle 24. So it would be particularly interesting to see a strong field emerge after the impending flip.

sun_magneticfield1Dean Pesnell, a project scientist for the space agency’s Solar Dynamics Observatory spacecraft at NASA’s Goddard Space Flight Center, the Sun’s latest field is likely to be a good indicator of what the next solar cycle is going to do. During its most recent cycle, known as Solar Cycle 24, the sun was rather quiet, so what happens next ought to be interesting:

If it quickly goes to a high value, then that tells us the next cycle will be high. We’ve had several of these solar minimums, and each time the polar field has been weaker. And each time, the next cycle has been a little bit weaker. So it would be nice to see one where the polar field strength was higher, and the next cycle was higher as well.

So rest easy, folks. No apocalyptic scenarios are likely to result from this latest, all-too-common solar phenomena. If anything, it will provide research benefits for scientists and aid in space exploration – especially for companies looking to mount missions to Mars in the next 11 years and trying to figure out a way around that tricky radiation problem.

As for the rest of us, we’re likely to maybe get a little break on the weather front. Maybe not. Kind of disappointing when you think about it…

But at least there’s a helpful video provided by Space.com. Enjoy!


Source:
space.com