Science & Technology


Astronauts may hibernate for Mars journey

© 20th Century Fox
A Nasa-backed study is exploring the feasibility of lowering the cost of a human expedition to Mars by putting the astronauts in deep sleep. The deep sleep, called torpor, would reduce astronauts' metabolic functions with existing medical procedures.

"Therapeutic torpor has been around in theory since the 1980s and really since 2003 has been a staple for critical care trauma patients in hospitals," said aerospace engineer Mark Schaffer, with SpaceWorks Enterprises in Atlanta, earlier this week at the International Astronomical Congress here. So far, the duration of a patient's time in torpor state has been limited to about one week.

Coupled with intravenous feeding, a crew could be put in hibernation for the transit time to Mars, which under the best-case scenario would take 180 days one-way. "We haven't had the need to keep someone in (therapeutic torpor) for longer than seven days. For human Mars missions, we need to push that to 90 days, 180 days," Schaffer said.

Comment: Torpor is a condition that can happen naturally from hypothermia. It shuts down most non-vital body processes and dramatically slows down the metabolism. The torpor state would be achieved by lowering body temperatures to somewhere between 89 and 93 degrees Fahrenheit. For every single degree the body temperature drops, its metabolic rate drops 5 to 7 percent. Researchers hope to get a 10 degree drop which would mean a 50 to 70 percent reduction in metabolic rate. The coma would be induced by letting the spaceship cool down in the freezing cold of space bringing the astronauts' body temperatures down, too. During interplanetary transit, the crew would receive low-level electrical impulses to key muscle groups to prevent muscles wasting away while in hibernation.

Blue Planet

Not so settled science: Gravity rivals join forces to nail down Big G

cavendish experiment 1798
A mock-up of a torsion balance used by British natural philosopher Henry Cavendish to measure G in 1798.
Metrologists meet to design the ultimate gravitational-constant experiment.

It is one of nature's most fundamental numbers, but humanity still doesn't have an accurate value for the gravitational constant. And, bafflingly, scientists' ability to pinpoint G seems to be getting worse. This week, the world's leading gravity metrologists are meeting to devise a set of experiments that will try to set the record straight. This will call for precision measurements that are notoriously difficult to make - but it will also require former rivals to work together.

Comment: Dr. Rupert Sheldrake on constants of nature


Comet Siding Spring: Close call for Mars, wake up call for Earth?

Comet Siding Spring
Five orbiters from India, the European Union and the United States will nestle behind Mars as comet Siding Springs passes at a speed of 200,000 km/hr (125,000 mph). At right, Shoemaker-Levy 9 impacts on Jupiter, the Chelyabinsk Asteroid over Russia.
It was 20 years ago this past July when images of Jupiter being pummeled by a comet caught the world's attention. Comet Shoemaker-Levy 9 had flown too close to Jupiter. It was captured by the giant planet's gravity and torn into a string of beads. One by one the comet fragments impacted Jupiter - leaving blemishes on its atmosphere, each several times larger than Earth in size.

Until that event, no one had seen a comet impact a planet. Now, Mars will see a very close passage of the comet Siding Spring on October 19th. When the comet was first discovered, astronomers quickly realized that it was heading straight at Mars. In fact, it appeared it was going to be a bulls-eye hit - except for the margin of error in calculating a comet's trajectory from 1 billion kilometers (620 million miles, 7 AU) away.

It took several months of analysis for a cataclysmic impact on Mars to be ruled out. So now today, Mars faces a just a cosmic close shave. But this comet packs enough energy that an impact would have globally altered Mars surface and atmosphere.
Solar Flares

Scientists observing the Birkeland currents

Plots of AMPERE magnetic perturbations and radial current density from the northern hemisphere for 24 February 2014 with start times from 1530 UT through 1700 UT.
When the supersonic solar wind hits the Earth's magnetic field, a powerful electrical connection occurs with Earth's field, generating millions of amperes of current that drive the dazzling auroras. These so-called Birkeland currents connect the ionosphere to the magnetosphere and channel solar wind energy to Earth's uppermost atmosphere. Solar storms release torrential blasts of solar wind that cause much stronger currents and can overload power grids and disrupt communications and navigation.

Now for the first time, scientists are making continuous, global measurements of the Birkeland currents, opening a new window on our understanding of our home planet's response to solar storms. Using the Active Magnetosphere and Planetary Electrodynamics Response Experiment, based on the 66 Iridium satellites orbiting the Earth, authors of a Geophysical Research Letters study have discovered that Earth's response to onsets in forcing from the solar wind occurs in two distinct stages.

Currents first appear near noon in the polar regions and remain steady for about half an hour. Then the second stage begins, when strong currents appear near midnight and eventually join the initial currents near noon. Most of the solar wind energy is deposited in the polar atmosphere by processes initiated in the second stage. The authors note that scientists are working to understand how the delay between the first and second stages could give near-term warning of impending space weather disruptions.

Fruit flies reveal features of human intestinal cancer

Tumor Growth
© Andreu Casali
This is a 4-week-old Drosophila gut with a large Apc-Ras tumor (in green).
Researchers in Spain have determined how a transcription factor known as Mirror regulates tumour-like growth in the intestines of fruit flies. The scientists believe a related system may be at work in humans during the progression of colorectal cancer due to the observation of similar genes and genetic interactions in cultured colorectal cancer cells. The results are reported in the journal EMBO Reports.

Colorectal cancer leads to more than half a million deaths worldwide each year. The disease originates in the epithelial cells of the gastrointestinal track mainly due to aberrations in the molecular signaling activities of cells.

"We have been able to use flies as a model system to study molecular events that are very similar to the steps that take place in colorectal cancer in humans and we have been able to use this system to identify new genetic regulations relevant to human disease," says Andreu Casali, lead author of the study and a research associate at the Institute for Research in Biomedicine in Barcelona.

Live and let-7: Do MicroRNA play a surprising role in cell survival?

© Credit: Thomas Deerinck, National Center for Microscopy and Imaging Research, UC San Diego
This is a scanning micrograph of dividing cancer cells.
Researchers at the University of California, San Diego School of Medicine have identified a microRNA molecule as a surprisingly crucial player in managing cell survival and growth. The findings, published in the October 7 issue of Cell Metabolism, underscore the emerging recognition that non-coding RNAs - small molecules that are not translated into working proteins - help regulate basic cellular processes and may be key to developing new drugs and therapies.

Specifically, principal investigator Albert R. La Spada, MD, PhD, professor of cellular and molecular medicine, chief of the Division of Genetics in the Department of Pediatrics and associate director of the Institute for Genomic Medicine at UC San Diego, and colleagues found that a microRNA known as let-7 controls autophagy through the amino acid sensing pathway, which has emerged as the most potent activator of mTORC1 complex activity.

Autophagy is a fundamental process used by cells to degrade unnecessary components in times of starvation, releasing energy stores that help promote cell survival. Cells have further adapted autophagy for other purposes as well, including recycling dysfunctional components, immune response to pathogen invasion, surveillance against cancer and maintenance of protein and organelle control in the central nervous system. MTORC1 is a critical protein complex that regulates energy consumption and growth in cells.

New Planck collaborative analysis: 'Big Bang Signal' could all be dust

There was little need, before, to know exactly how much dust peppers outer space, far from the plane of the Milky Way. Scientists understood that the dimly radiating grains aligned with our galaxy's magnetic field and that the field's twists and turns gave a subtle swirl to the dust glow. But those swirls were too faint to see. Only since March, when researchers claimed to have glimpsed the edge of space and time with a fantastically sensitive telescope, has the dust demanded a reckoning. For, like a cuckoo egg masquerading in a warbler's nest, its pattern mimics a predicted signal from the Big Bang.

Now, scientists have shown that the swirl pattern touted as evidence of primordial gravitational waves - ripples in space and time dating to the universe's explosive birth - could instead all come from magnetically aligned dust. A new analysis of data from the Planck space telescope has concluded that the tiny silicate and carbonate particles spewed into interstellar space by dying stars could account for as much as 100 percent of the signal detected by the BICEP2 telescope and announced to great fanfare this spring.

The Planck analysis is "relatively definitive in that we can't exclude that the entirety of our signal is from dust," said Brian Keating, an astrophysicist at the University of California, San Diego, and a member of the BICEP2 collaboration.

"We were, of course, disappointed," said Planck team member Jonathan Aumont of the Université Paris-Sud.

Coffee lover? It could be in your genes

Woman drinking coffee
© Mila Supinskaya/Shutterstock
For some, coffee is the true nectar of the gods, while others won't touch a drop of the stuff. Now, a new study reveals how genes influence people's preferences for a cup o' Joe.

Researchers analyzed genetic data from studies of more than 120,000 coffee drinkers of European and African-American ancestry. They found eight locations of the human genome linked with coffee drinking, six of which had never been linked to consumption of the beverage before, according to the study, published today (Oct. 7) in the journal Molecular Psychiatry.

The findings further boost the idea that a hit of caffeine is what motivates regular coffee consumption, and could explain why the same amount of coffee or caffeine can have enormously different effects on different people.

"Coffee, a major dietary source of caffeine, is among the most widely consumed beverages in the world and has received considerable attention regarding health risks and benefits," the researchers wrote in the study.

Research consistently suggests that drinking coffee is linked to a lower risk of type 2 diabetes, liver disease and Parkinson's disease, the researchers said. However, the effects of coffee on cancer risk, cardiovascular health, pregnancy and other conditions remain unclear.

New vote for Pluto's reinstatement as a planet

Planet Pluto
Up for debate...again.
What is a planet? For generations of kids the answer was easy. A big ball of rock or gas that orbited our Sun, and there were nine of them in our solar system. But then astronomers started finding more Pluto-sized objects orbiting beyond Neptune. Then they found Jupiter-sized objects circling distant stars, first by the handful and then by the hundreds. Suddenly the answer wasn't so easy. Were all these newfound things planets?

Since the International Astronomical Union (IAU) is in charge of naming these newly discovered worlds, they tackled the question at their 2006 meeting. They tried to come up with a definition of a planet that everyone could agree on. But the astronomers couldn't agree. In the end, they voted and picked a definition that they thought would work.

The current, official definition says that a planet is a celestial body that:
  1. is in orbit around the Sun,
  2. is round or nearly round, and
  3. has "cleared the neighborhood" around its orbit.
But this definition baffled the public and classrooms around the country. For one thing, it only applied to planets in our solar system. What about all those exoplanets orbiting other stars? Are they planets? And Pluto was booted from the planet club and called a dwarf planet. Is a dwarf planet a small planet? Not according to the IAU. Even though a dwarf fruit tree is still a small fruit tree, and a dwarf hamster is still a small hamster.

Eight years later, the Harvard-Smithsonian Center for Astrophysics decided to revisit the question of "what is a planet?" On September 18th, we hosted a debate among three leading experts in planetary science, each of whom presented their case as to what a planet is or isn't. The goal: to find a definition that the eager public audience could agree on!

Comment: After the IAU decision to downgrade Pluto by four percent of its members, most of whom are not planetary scientists, it was immediately opposed in a formal petition by hundreds of professional astronomers. Part of the issue is that the term "minor planet" is a synonym for asteroids and comets, bodies too small to be rounded by gravity. Regardless of its size, Pluto still meets much of the planetary "criteria." The recent feel-good vote was not official nor binding.

As the bumpersticker says: Honk if Pluto is still a planet...

The video of the debate and audience vote can be seen on YouTube at


"Kernel" lexicon of languages remains stable in the long run

© Stock Photo
The frequency with which we use different words changes all the time, new words are invented or fall out of use. Yet little is known about the dynamics of lexical change across languages. Researchers of Kazan Federal University in Russia and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have now studied the lexical evolution of English in comparison to Russian, German, French, Spanish and Italian using the Google Books N-Gram Corpus. They found that major societal transformations such as wars cause faster changes in word frequency distributions, whereas lexical evolution is dampened during times of stability, such as the Victorian Era.

Furthermore, the researchers found British and American English to drift apart during the first half of the 20th century, but then begin to re-converge, likely due to the mass media. Apart from these peculiarities, however, the researchers also find similar rates of change across languages at larger time scales, revealing universal trends governing lexical evolution.

The lexicon of a language reflects the world of its speakers. Accordingly, changes in the lexicon of a language reflect changes in the environment. In their current study Søren Wichmann of the Max Planck Institute for Evolutionary Anthropology and his collaborators of Kazan Federal University studied the dynamics of lexical evolution over time and across languages. To this aim the researchers used the Google Books N-Gram Corpus to monitor word usage during the past five centuries. Wichmann and colleagues focused on single words, so-called 1-grams, from six different languages and looked specifically at how frequently these words were used year by year.