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Methane on Saturn --- The soft, bright-and-dark bands displayed by Saturn in this view from NASA's Cassini spacecraft are the signature of methane in the planet's atmosphere. The moon Dione hangs below the rings at right. Credit: NASA/JPL-Caltech/Space Science Institute. [Reply]
NASA's Kepler mission has verified 1,284 new planets – the single largest finding of planets to date.
“This announcement more than doubles the number of confirmed planets from Kepler,” said Ellen Stofan, chief scientist at NASA Headquarters in Washington. “This gives us hope that somewhere out there, around a star much like ours, we can eventually discover another Earth.”
Analysis was performed on the Kepler space telescope’s July 2015 planet candidate catalog, which identified 4,302 potential planets. For 1,284 of the candidates, the probability of being a planet is greater than 99 percent – the minimum required to earn the status of “planet.” An additional 1,327 candidates are more likely than not to be actual planets, but they do not meet the 99 percent threshold and will require additional study. The remaining 707 are more likely to be some other astrophysical phenomena. This analysis also validated 984 candidates previously verified by other techniques.
"Before the Kepler space telescope launched, we did not know whether exoplanets were rare or common in the galaxy. Thanks to Kepler and the research community, we now know there could be more planets than stars,” said Paul Hertz, Astrophysics Division director at NASA Headquarters. "This knowledge informs the future missions that are needed to take us ever-closer to finding out whether we are alone in the universe."
Kepler captures the discrete signals of distant planets – decreases in brightness that occur when planets pass in front of, or transit, their stars – much like the May 9 Mercury transit of our sun. Since the discovery of the first planets outside our solar system more than two decades ago, researchers have resorted to a laborious, one-by-one process of verifying suspected planets.
This latest announcement, however, is based on a statistical analysis method that can be applied to many planet candidates simultaneously. Timothy Morton, associate research scholar at Princeton University in New Jersey and lead author of the scientific paper published in The Astrophysical Journal, employed a technique to assign each Kepler candidate a planet-hood probability percentage – the first such automated computation on this scale, as previous statistical techniques focused only on sub-groups within the greater list of planet candidates identified by Kepler.
"Planet candidates can be thought of like bread crumbs,” said Morton. “If you drop a few large crumbs on the floor, you can pick them up one by one. But, if you spill a whole bag of tiny crumbs, you're going to need a broom. This statistical analysis is our broom."
In the newly-validated batch of planets, nearly 550 could be rocky planets like Earth, based on their size. Nine of these orbit in their sun's habitable zone, which is the distance from a star where orbiting planets can have surface temperatures that allow liquid water to pool. With the addition of these nine, 21 exoplanets now are known to be members of this exclusive group.
"They say not to count our chickens before they're hatched, but that's exactly what these results allow us to do based on probabilities that each egg (candidate) will hatch into a chick (bona fide planet)," said Natalie Batalha, co-author of the paper and the Kepler mission scientist at NASA's Ames Research Center in Moffett Field, California. “This work will help Kepler reach its full potential by yielding a deeper understanding of the number of stars that harbor potentially habitable, Earth-size planets -- a number that's needed to design future missions to search for habitable environments and living worlds.”
Of the nearly 5,000 total planet candidates found to date, more than 3,200 now have been verified, and 2,325 of these were discovered by Kepler. Launched in March 2009, Kepler is the first NASA mission to find potentially habitable Earth-size planets. For four years, Kepler monitored 150,000 stars in a single patch of sky, measuring the tiny, telltale dip in the brightness of a star that can be produced by a transiting planet. In 2018, NASA’s Transiting Exoplanet Survey Satellite will use the same method to monitor 200,000 bright nearby stars and search for planets, focusing on Earth and Super-Earth-sized.
Ames manages the Kepler missions for NASA’s Science Mission Directorate in Washington. The agency’s Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system, with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.
For more information about the Kepler mission, visit:
You’re not often aware of it, but there’s bloatware embedded in the operating system between your ears.
Occasionally, it’s useful, but for the most part, it’s vestigial dead weight. These are the pre-installed cognitive systems that make me like shiny things, because some hairy ancestors were once naturally selected for their ability to find life-giving, shimmering water. And, I have an amusingly visceral fear of snorkelling, despite my ‘don’t breathe underwater’ instinct being made redundant by snorkels.
There’s one particular piece of redundant psychological software I’ve had some direct experience with in my career, as an advocate for new forms of clean energy technology in Australia. When it comes to detecting potential threats to our safety, we over-estimate the threat posed by things we can’t see. The parts of our world we use scientific tools to detect, such as electromagnetic radiation, inaudible sound and nanoparticles, are more likely to be perceived as harmful – regardless of our ability to to measure exposure, and determine the levels at which these agents cause damage.
A perfect example of the power of this factor in risk perception is our fear of electromagnetism. Recently, I was listening to an ABC Radio National interview about a new form of nano-structured battery gel – the host asked the developer of the technology:
“As I understand it your battery, the battery gel, is designed so it could be built into the walls of a new construction, when I heard that I was a little bit worried about the thought of living in a house with batteries all around me, in the walls, is that dangerous?”
“That’s why I went into a little bit of detail about why it is safe.”
“I’m not worried about the fire thing. I’m worried about just, I don’t know, are there waves? Electromagnetic waves or anything?”
The scientist responded with reassurances, but the host’s question highlights the continued existence of concerns about invisible electromagnetic radiation. In fact, community reactions to electromagnetism have seen a strong resurgence in recent years – the Australian Radiation and Protection Nuclear Safety Agency (ARPANSA) have a little-known but well-kept register of all complaints sent their way, regarding perceived adverse health reactions to electromagnetic fields – their most recent report shows a spike in 2012:
The majority of cumulative reports over the full period come from Victoria, and relate to smart meters. It’s a good reminder of another big factor in how we respond to new technology – if we feel it’s forced on us by a government authority, people are more likely to respond with skewed perception of risk. Within this complex mix of factors, ‘invisibility’ will often feature.
This part of our internal logic becomes prevalent in almost any technology that features something we can’t detect with our visual system. In 2012, a government survey of 1,000 people examined attitudes towards the use of nanoparticles in sunscreen and found that “Thirteen percent of this group were concerned or confused enough that they would be less likely to use any sunscreen, whether or not it contained nanoparticles, putting themselves at increased risk of developing potentially deadly skin cancers”. The Cancer Council, the Therapeutic Goods Administration and Choice all state that the use of nanoparticles in sunscreen is safe. That you cannot visually distinguish a sunscreen containing nanoparticles from one that doesn’t played a big part in this skewed risk perception – probably catalysed by the fact that a huge number of sunscreens were mislabelled.
Invisibility plays a big part in the emergence of health fears around wind turbine technology, too – the risk is described as pervasive, inescapable and totally undetectable using normal senses. A submission to a recent senate inquiry into wind farms claims that “We know there are many things that we cannot SMELL that can harm us. The lethal dangers of breathing carbon monoxide or carbon dioxide are well established. We know there are things that we cannot SEE that can harm us. It is well established that ultraviolet light is invisible, yet it can make someone’s life miserable, with skin burns and eye damage if they are exposed to excessive amounts. The purported causal agent in this phenomenon, ‘infrasound’, is defined as sound below the hearing threshold of the human ear – around 20 Hz. Sound at this frequency is everywhere – you’re exposed to it when you drive, when you walk and when you stand near a fridge. Curiously, ultrasound (also inaudible but above the threshold of human hearing) has also been suggested as a ‘cause’ of this phenomenon.
Though ‘infrasound’ has stuck, both fit the criteria – they cannot be detected using normal human senses, creating a threat that’s pervasive, uncertain and undetectable. It also creates a niche industry in spurious ‘threat detection’ – stories on prime time current affair shows featuring the misinterpretation of EMF meters thrive on this.
Each of these are complex cultural phenomena. Plenty of invisible threats that science has confirmed are dangerous seem to be undervalued, too. Consider the threat posed by pumping obscene quantities of invisible greenhouse gases into the atmosphere (followed, naturally, with vague and ludicrous assertions that the entire planet’s scientific community has made an enormous accidental and coincidental mistake). In this instance, the agent involved threatens us indirectly, as opposed to the direct physical harm creating concern with agents like electromagnetism or infrasound, which seems to denature our fear. The sun’s radiation is invisible, yet we still take unreasonable risks with regards to exposure. This is because we perceive human-made agents as risky, and natural agents as safe – something known as the ‘appeal to nature’.
Our in-built fear of invisible threats makes a weird sort of sense, when you consider that most of our in-built threat detection systems are geared very much towards moving organisms that look like they’re probably going to hurt us. Radiation, sound and tiny particles are all things we’ve heard can be harmful, but the nuances of dosage and amplitude are boring candidates for our attention.
These are ancient parts of our brain’s operating system, and there’s really no way to uninstall this bloatware. It’s part of our thinking, and it’s now increasingly valuable to understand and preempt these features, particularly considering the increasing role of wireless communications in technology. Most recently, the rollout of the wireless NBN network could go more smoothly if health fears around them are better understood – which includes acknowledging and understanding that each of us is bundled with pre-installed bloatware. [Reply]
Researchers have cracked the secret of the internal, genetically encoded compass that millions of monarch butterflies use to determine the direction -- southwest -- they should fly each fall to reach central Mexico.
Each fall, monarch butterflies across Canada and the United States turn their orange, black and white-mottled wings toward the Rio Grande and migrate over 2,000 miles to the relative warmth of central Mexico.
This journey, repeated instinctively by generations of monarchs, continues even as monarch numbers have plummeted due to loss of their sole larval food source -- milkweed. But amid this sad news, a research team believes they have cracked the secret of the internal, genetically encoded compass that the monarchs use to determine the direction -- southwest -- they should fly each fall.
"Their compass integrates two pieces of information -- the time of day and the sun's position on the horizon -- to find the southerly direction," said Eli Shlizerman, a University of Washington assistant professor.
While the nature of the monarch butterfly's ability to integrate the time of day and the sun's location in the sky are known from previous research, scientists have never understood how the monarch's brain receives and processes this information. Shlizerman, who has joint appointments in the Department of Applied Mathematics and the Department of Electrical Engineering, partnered with colleagues at the University of Michigan and the University of Massachusetts to model how the monarch's compass is organized within its brain.
"We wanted to understand how the monarch is processing these different types of information to yield this constant behavior -- flying southwest each fall," said Shlizerman, who is lead author on the team's recent paper in the journal Cell Reports.
Monarchs use their large, complex eyes to monitor the sun's position in the sky. But the sun's position is not sufficient to determine direction. Each butterfly must also combine that information with the time of day to know where to go. Fortunately, like most animals including humans, monarchs possess an internal clock based on the rhythmic expression of key genes. This clock maintains a daily pattern of physiology and behavior. In the monarch butterfly, the clock is centered in the antennae, and its information travels via neurons to the brain.
Biologists have previously studied the rhythmic patterns in monarch antennae that control the internal clock, as well as how their compound eyes decipher the sun's position in the sky. Shlizerman's collaborators, including Steven Reppert at the University of Massachusetts, recorded signals from antennae nerves in monarchs as they transmitted clock information to the brain as well as light information from the eyes.
"We created a model that incorporated this information -- how the antennae and eyes send this information to the brain," said Shlizerman. "Our goal was to model what type of control mechanism would be at work within the brain, and then asked whether our model could guarantee sustained navigation in the southwest direction."
In their model, two neural mechanisms -- one inhibitory and one excitatory -- controlled signals from clock genes in the antennae. Their model had a similar system in place to discern the sun's position based on signals from the eyes. The balance between these control mechanisms would help the monarch brain decipher which direction was southwest.
Based on their model, it also appears that during course corrections monarchs do not simply make the shortest turn to get back on route. Their model includes a unique feature -- a separation point that would control whether the monarch turned right or left to head in the southwest direction.
"The location of this point in the monarch butterfly's visual field changes throughout the day," said Shlizerman. "And our model predicts that the monarch will not cross this point when it makes a course correction to head back southwest."
Based on their simulations, if a monarch gets off course due to a gust of wind or object in its path, it will turn whichever direction won't require it to cross the separation point.
Additional studies would need to confirm whether the researchers' model is consistent with monarch butterfly brain anatomy, physiology and behavior. So far, aspects of their model, such as the separation point, seem consistent with observed behaviors.
"In experiments with monarchs at different times of the day, you do see occasions where their turns in course corrections are unusually long, slow or meandering," said Shlizerman. "These could be cases where they can't do a shorter turn because it would require crossing the separation point."
Their model suggests a simple explanation why monarch butterflies are able to reverse course in the spring and head northeast back to the United States and Canada. The four neural mechanisms that transmit information about the clock and the sun's position would simply need to reverse direction.
"And when that happens, their compass points northeast instead of southwest," said Shlizerman. "It's a simple, robust system to explain how these butterflies -- generation after generation -- make this remarkable migration." [Reply]
Space may seem the most awesome and beautiful travel destination, but being an astronaut is something only a few will ever get to experience. But although being an astronaut may seem as the coolest job ever, it is far from glamourous. Because being in space can take a huge toll on your body, and some of it is just really gross
Here are some fascinating but gross things that can happen to your body when you’re floating around in space:
Dead skin cells fall off in huge chunks
When in you’re living in the International Space Station for two to three months all the callouses on the bottom of your feet are starting to fall off. This is due to the fact that astronauts spend most of their time floating around instead of walking. Pretty gross right?!
Your face will get puffy and you will get skinny legs
Due to gravity the fluids in our body are not evenly distributed, but in in space this changes radically. Thanks to microgravity all the body fluids will get evenly redistributed and therefore our legs appear skinnier and faces puffier.
Space sickness instead of sea sickness
During the first days in space most of the astronauts experience some sort of space sickness. It feels like having a huge hangover, but then combined with motion sickness and an inability to locate your limbs. This is all due to the fact that microgravity throws off your sense of direction. So in a certain way you can compare it with being sea sick.
So as you can see being in space isn’t all fun and games! [Reply]