Humanity is one asteroid impact away from being wiped out

 If a natural disaster such as a hurricane or a tornado is coming your way, it will inevitably cause a significant amount of damage, but at least you could have the chance to get out of harms way. But how would you evacuate in the event of a natural disaster from outer space, capable of wiping out entire species in a relatively short amount of time? Is the potential for an asteroid colliding with earth one of our planet’s greatest threats?

“Sooner or later we will get… a minor or major impact,” says Rolf Densing, head of the European Space Operations Centre (ESOC) in Darmstadt, Germany. Densing explained that even though we may not be alive to see it happen, “the risk that Earth will get hit in a devastating event one day is very high.”

Asteroid sizes range from just a few millimeters to over 6 miles in length, which astrophysicists believe is the size of the space rock that wiped out the dinosaurs millions of years ago. What’s worse is that if one of these gigantic asteroids were to enter Earth’s atmosphere again, there’s really nothing we would be able to do to stop it.

“We are not ready to defend ourselves” in the event that an asteroid begins falling towards our planet, said Densing. “We have no active planetary defense measures.”

We know that the largest types of asteroids – the kind that are capable of wiping out all life on our planet – strike Earth about once every 100 million years. But even though we have a general idea of the impact frequency of these behemoth space rocks, there are still many things we don’t know. How big will it be exactly? Will it wipe out all of humanity, or will there be survivors? And by the time a giant asteroid does begin falling towards Earth, will we have the technology to intercept it or destroy it?

Over the past several years, NASA has been working on a program called the Planetary Defense Coordination Office, which locates objects in space, like asteroids, and issues warnings when an impact with Earth is possible (RELATED: NASA only has a 10 percent chance of detecting asteroids before they hit Earth.) Likewise, the Japanese Aerospace Exploration Agency is in the process of acquiring $450 million to send an advanced telescope into space in order to track giant space rocks that could potentially collide with our planet.

But studying and tracking asteroids near Earth is only half of the battle, because all of the data in the world wouldn’t be able to stop one of these rocky behemoths from slamming into our world. We would still be faced with the task of either pushing the asteroid out of the way or blowing it to pieces.

Jason P. Dworkin of NASA’s Goddard Space Flight Center in Maryland says that the action taken to intercept an asteroid depends on certain factors, like how much time we have and the asteroid’s shape. “If it was up to me, I would send a rocket with some titanium dioxide on it and paint it white, and have that Yarkovksy effect accelerate, and move it away from the Earth,” Dworkin explained. He adds, “If you have something like 50 years, that could deflect it enough, and it might be a whole lot simpler than sending up nuclear weapons.”

Given the numerous threats that we are already trying to deal with today, it’s understandable that the potential of an asteroid hitting Earth is not something that is often discussed. However, it is important that we not only continue to track asteroids floating around in outer space, but also that we continue to develop new technology that one day could be used to save the human race.

Sources include:

Phys.org

NBCnews.com

Beyond “grid down” – Solar flares can also disrupt railway signaling systems and underground conduit pipes

Solar flares may negatively impact the planet’s power grids, railway systems, and underground pipelines through a phenomenon called geomagnetically induced currents (GICs), a recent study found. These effects may disrupt food logistics, manufacturing, electronic transactions and internet functions, experts warn.

To examine how solar storm-induced GICs affect the planet’s structures, scientists at the National Aeronautics and Space Administration (NASA) collaborated with heliospheric scientists, magnetospheric physicists, power engineers, and emergency management officials from various research institutions and industries during a pair of intensive week-long workshops in 2016.

According to researchers, the sun regularly ejects a stream of magnetic solar material called solar wind, as well as occasional huge clouds of solar material known as coronal mass ejections. The research team said these solar materials interact with the planet’s magnetic field, which in turn leads to temporary changes. As a result, geomagnetically induced currents are formed just under the planet’s surface.

The team also noted that long, thin, metal structures near the planet’s surface —  including underground railroads, power lines and pipelines — may serve as conductors for these GICs. This means that electric currents may easily travel underground, the researchers said. In effect, GICs may negatively affect all these structures, the experts added.

How GICs affect power systems, railways and pipelines

The research team cautioned that GICs may be more challenging to manage in affected power systems, as they require careful control of electric currents to keep the power on. According to the researchers, GICs from strong solar activities may also lead to voltage collapse. Voltage collapse can cause temporary blackouts in certain areas, and may affect various industries such as transportation, health care, and commerce. However, researchers noted that GICs were unlikely to cause major power system damages. (Related: Know more about the latest developments in space science at Space.news).

“For permanent transformer damage to occur, there needs to be sustained levels of GICs going through the transformer. We know that’s not how GICs work. GICs tend to be much more noisy and short-lived, so widespread physical damage of transformers is unlikely even during major storms,” said Antti Pulkkinen, a Space Weather Researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The study also found that GICs may interfere with railway signals. As per the research team, these railway signals typically operate on an automated closed/open circuit system, which determines whether a train is on the track. The study revealed that GICs may alter these signals, which in turn may prompt the system to detect a train when there is actually none. The study also showed that GICs flowing in pipelines may produce false signals. In turn, this may prompt pipeline workers to inspect otherwise normally functioning pipelines.

The team’s previous research on GCIs have lead to the adoption of new standards in preventing blackouts. In fact, the Federal Energy Regulatory Commission now requires power companies to prepare for potential GIC disruptions.

The findings were published in the journal Space Weather.

Chinese study demonstrates how GCIs affect power grids

A Chinese study published in 2008 has shown how GCIs impact power grid operations. According to the researchers, unknown severe transformer vibration and increased noise have been noted in certain parts of Guandong, China when two power transmission lines — the Yang-Huai power transmission system and a 500 kV long-distance transmission line — started operating in 2001. To determine the mechanism behind the phenomena, the research team compared more than ten magnetic storms and examined data on transformer neutral currents. The experts then concluded GCIs caused the disturbances.

In addition, the research team also noted that GIC levels in Guangdong Power Grid was much higher compared with those of Yang-Huai power transmission system. However, grid structure and coast effect may have contributed to this, the experts said. The findings were published in the Chinese Journal of Geophysics.

Sources include: 

ScienceDaily.com

NASA.gov

OnlineLibrary.Wiley.com

Scientists now claim “dark energy” – which makes up 68% of the entire cosmos – may be totally imaginary

Dark energy is not so dark anymore…or existent. A new study published in the Monthly Notices of the Royal Astronomical Society asserts that the enigmatic dark energy doesn’t really exist. For the last two decades, it was believed that 68% of the universe was made from dark energy (in contrast, dark matter makes up 27% of the universe, while “ordinary” matter only accounts for 5%). This dark energy explained that little something-something that described the motion of stars within galaxies, including the acceleration rate in which the universe expanded. And yes, that phrase was used intentionally: the fact is, astronomers had no real clue what they were seeing or how it influenced the universe.

According to conventional theories of astrophysics, the universe was formed by the Big Bang almost 14 billion years ago. It has been expanding ever since. This is based on Hubble’s law, which states that on average, the speed in which a galaxy  moves away from us is proportional to its distance. The velocity of this recession can be seen by looking at lines in the spectrum of a galaxy, which shift to red the faster the galaxy is moving away. It is this mathematical model that proved that the universe is expanding and that it began life as a small point. Still, scientists were never able to explain the force that drove the acceleration.

Observations of the explosions of white dwarf stars in binary systems, called Type Ia supernovae in the 1990s, “confirmed” to scientists that there was a third previously-unknown component to the universe. Astronomers named this component dark energy.

This new study questions these assumptions. Lead author, Ph.D. student Gábor Rácz of Eötvös Loránd University in Hungary, says that relying on the conventional models of cosmology ignores the uniform density of matter itself. This is because scientists rely too much on approximations rather than seeing other possibilities.

Co-author of the study, Dr. László Dobos explains in an article published in ScienceDaily.com, “Einstein’s equations of general relativity that describe the expansion of the universe are so complex mathematically that for a hundred years no solutions accounting for the effect of cosmic structures have been found. We know from very precise supernova observations that the universe is accelerating, but at the same time we rely on coarse approximations to Einstein’s equations which may introduce serious side-effects, such as the need for dark energy, in the models designed to fit the observational data.”

The darkness of illusion

Is the universe’s acceleration just driven by mere variations or inhomogeneities? If the researchers are to be believed, this could explain one of the biggest mysteries in physics with nothing more than the old-familiar general theory of relativity explained by Albert Einstein years ago. Naturally, some researchers remain skeptical. Tom Giblin, a Computational Cosmologist at Kenyon College in Gambier, Ohio said in an article in ScienceMag.com, “I would love if inhomogeneities explained dark energy…[but] I don’t see any evidence from our simulations to expect it to be as big an effect as they see here.”

The issue at hand is that the new study questions computational models that have been used for 20 years. Simply speaking, cosmologists relied on two equations to describe how the universe evolved. One defines how matter coalesces into galaxies, while the other (known as the  Friedmann–Lemaître–Robertson–Walker (FLRW) metric) is based on Einstein’s theory of gravity and hopes to explain how much the universe has expanded at any given time. Dark energy models relied on FLRW to explain its function. Needless to say, astronomers have had varying results. This, the new research says, is because FLRW equations apply only to a smooth and homogeneous universe. This is already questionable, considering that general relativity says that mass and energy warp space-time. Thus, in principle, inhomogeneities are more likely to affect the universe’s expansion rather than calculated simulations.

The new study’s computational model on inhomogeneities suggest that studying these vectors are more relevant to understanding the universe than previous research. Still, experts argue for more data. “Mainstream cosmology has done such a bad job of solving the dark energy problem that it will likely be some nonmainstream idea like this that does,” says Giblin. However, he adds, “I don’t know if this is the one.”

Learn more about the universe and space technology by reading the articles at Space.news.

Sources include:

ScienceDaily.com

ScienceMag.com

Science.NASA.gov