"When you believe that you have adequate, expert knowledge, a passive, logical, deductive form of mental activity seems appropriate. Deduction always goes from a higher level of generality to a lower level of generality. Mental passivity therefore is likely to be associated with the belief that we have the decisive knowledge already stored in memory. If we believe that we create higher degrees of generality, as appropriate solutions to novel problems, then we are committed to an active mental life. Perception, combined with the discovery and invention of new patterns in the world, will be actively oriented toward the future, while the deductive, merely analytical, manner of thought will be tied to the past."
Watery science ‘jackpot’ discovered by Curiosity
The Curiosity rover hit the science “jackpot” and has discovered widespread further evidence of multiple episodes of liquid water flowing over ancient Mars billions of years ago when the planet was warmer and wetter, scientists announced. The watery evidence comes in the form of water bearing mineral veins, cross-bedded layering, nodules and spherical sedimentary concretions.
Delighted researchers said Curiosity surprisingly found lots of evidence for light-toned chains of linear mineral veins inside fractured rocks littering the highly diverse Martian terrain – using her array of ten state-of-the-art science instruments. Veins form when liquid water circulates through fractures and deposit minerals, gradually filling the insides of the fractured rocks over time.
Shortly after landing the team took a calculated gamble and decided to take a several months long detour away from the main destination of the towering, sedimentary mountain named Mount Sharp, and instead drive to an area dubbed ‘Glenelg’ and home to ‘Yellowknife Bay’, because it sits at the junction of a trio of different geologic terrains. Glenelg exhibits high thermal inertia and helps put the entire region in better scientific context. The gamble has clearly payed off.
The Chemistry and Camera (ChemCam) instrument found elevated levels of calcium, sulfur and hydrogen. Hydrogen is indicative of water. The mineral veins are probably comprised of calcium sulfate – which exists in several hydrated (water bearing) forms.
Curiosity will be instructed to drive over the veins to try and break them up and expose fresh surfaces for analysis. Then she will drill directly into a vein and hopefully catch some of the surrounding material as well.
“This will reveal the mineralogy of the vein filling material and how many hydrated mineral phases are present. The main goal is this will give us an assessment of the habitability of this environment.”
Image credit: NASA
NASA’s Kepler mission confirmed the discovery of its first rocky planet, named Kepler-10b. Measuring 1.4 times the size of Earth, it is the smallest planet ever discovered outside our solar system.
Einstein Was Right: Space-Time Is Smooth, Not Foamy
Space-time is smooth rather than foamy, a new study suggests, scoring a possible victory for Einstein over some quantum theorists who came after him.
In his general theory of relativity, Einstein described space-time as fundamentally smooth, warping only under the strain of energy and matter. Some quantum-theory interpretations disagree, however, viewing space-time as being composed of a froth of minute particles that constantly pop into and out of existence.
It appears Albert Einstein may have been right yet again.
A team of researchers came to this conclusion after tracing the long journey three photons took through intergalactic space. The photons were blasted out by an intense explosion known as a gamma-ray burst about 7 billion light-years from Earth. They finally barreled into the detectors of NASA’s Fermi Gamma-ray Space Telescope in May 2009, arriving just a millisecond apart.
Their dead-heat finish strongly supports the Einsteinian view of space-time, researchers said. The wavelengths of gamma-ray burst photons are so small that they should be able to interact with the even tinier “bubbles” in the quantum theorists’ proposed space-time foam.
If this foam indeed exists, the three protons should have been knocked around a bit during their epic voyage. In such a scenario, the chances of all three reaching the Fermi telescope at virtually the same time are very low, researchers said.
So the new study is a strike against the foam’s existence as currently imagined, though not a death blow.
“If foaminess exists at all, we think it must be at a scale far smaller than the Planck length, indicating that other physics might be involved,” study leader Robert Nemiroff, of Michigan Technological University, said in a statement. (The Planck length is an almost inconceivably short distance, about one trillionth of a trillionth the diameter of a hydrogen atom.)
“There is a possibility of a statistical fluke, or that space-time foam interacts with light differently than we imagined,” added Nemiroff, who presented the results Wednesday (Jan. 9) at the 221st meeting of the American Astronomical Society in Long Beach, Calif.
If the study holds up, the implications are big, researchers said.
“If future gamma-ray bursts confirm this, we will have learned something very fundamental about our universe,” Bradley Schaefer of Louisiana State University said in statement.
(Source: , via itsfullofstars)
China prepares to grow vegetables on Mars
Chinese astronauts are preparing to grow fresh vegetables on Mars and the moon after researchers successfully completed a preliminary test in Beijing, state media reported.
Four kinds of vegetables were grown in an “ecological life support system”, a 300 cubic metre cabin which will allow astronauts to develop their own stocks of air, water and food while on space missions, Xinhua news agency said Monday.
The system, which relies on plants and algae, is “expected to be used in extra-terrestrial bases on the moon or Mars”, the report said.
Participants in the experiment could “harvest fresh vegetables for meals”, Xinhua quoted Deng Yibing, a researcher at Beijing’s Chinese Astronaut Research and Training Centre, as saying.
“Chinese astronauts may get fresh vegetables and oxygen supplies by gardening in extra-terrestrial bases in the future,” the report said, adding that the experiment was the first of its kind in China.
China has said it will land an exploratory craft on the moon for the first time next year, as part of an ambitious space programme that includes a long-term plan for a manned moon landing.
The Asian superpower has been ramping up its manned space activities as the United States, long the leader in the field, has scaled back some of its programmes, such as retiring its iconic space shuttle fleet.
In its last white paper on space, China said it was working towards landing a man on the moon — a feat so far only achieved by the United States, most recently in 1972 — although it did not give a time frame.
China’s first astronaut Yang Liwei said last month that Chinese astronauts may start a branch of China’s ruling Communist Party in space, state media reported.
“If we establish a party branch in space, it would also be the ‘highest’ of its kind in the world,” Xinhua quoted Yang as saying.
The astronaut was launched into space and orbited the earth aboard the Shenzhou 5 spacecraft in 2003.
Frozen Water and Organic Material Discovered on Mercury
For the first time, scientists have confirmed that the planet Mercury holds at least 100 billion tons of water ice as well as organic material in permanently shadowed craters at its north pole.
The findings come from NASA’s MESSENGER spacecraft, which has been in orbit around the solar system’s smallest and innermost planet since 2011. Researchers have suspected that ice could exist in such craters since 1992, when Earth-based radar measurements found bright areas at the planet’s polar regions. Craters in this area cast long shadows, which prevent any sunlight from reaching their floors.
Though alternative explanations had been put forward to account for the radar-bright areas, MESSENGER has provided convincing evidence for water ice on the planet closest to our sun, where surface temperatures can sometimes reach 800 degrees Fahrenheit. The results appeared in three studies Nov. 29 in Science.
MESSENGER was able to detect water ice because it carries a neutron spectrometer that looks at energetic neutrons bouncing off Mercury’s surface. Water gives off a characteristic neutron signature. The spacecraft measured the area around Mercury’s north pole and found this characteristic signature, suggesting that between 100 billion and 1 trillion tons of water ice was present somewhere in the area. But the neutron spectrometer has fairly low resolution, on the order of hundreds of miles, so it can’t definitively say if this water is inside the craters. (If it were outside, daytime temperatures would have boiled the water away.)
Because they contain no light, MESSENGER’s cameras can’t see right inside the permanently shadowed regions. But the spacecraft carries a useful workaround tool. To map its height above the surface, the probe uses an altimeter that shoots a 10-nanosecond infrared laser pulse at the ground and intercepts the returning beam.
“We can measure the energy that comes back from the laser,” said planetary scientist Gregory Neumann of NASA’s Goddard Spaceflight Center, and lead author on one of the Science studies. Though the number of photons coming back is slight, “we could expect to see glints of brightness from surface water ice.”
Early results from MESSENGER presented a puzzle. Not only were there no bright spots in the permanently shadowed craters where radar measurements suggested ice, the surface was actually much darker than Mercury’s average color. “We were really surprised by this,” said Neumann.
The spacecraft continued to search, examining more and more craters. Finally, the laser spotted some dazzling crater floors that were two to four times brighter than the rest of Mercury’s surface. This was finally good evidence for the long-sought water ice. By modeling the temperature in and around different craters, scientists were able to determine the northernmost craters stayed cold enough over millions of years to hold onto water ice.
But what about the strange dark craters? Radar measurements suggested ice, but MESSENGER wasn’t confirming the result. The temperature models showed that these craters corresponded exactly to regions that would sometimes receive a small amount of scattered sunlight. This itsy bit of energy would heat the frozen water’s surface enough to sublimate it away. Dark organic compounds dissolved in the ice got left behind as residue and would slowly form a black cover, about 8 to 11 inches thick, which protected any remaining ice from getting vaporized by random sunbeams.
The organic material is likely made of hydrocarbons like methane and ethane, commonly found in comets and asteroids. “At room temperature it would be kind of gooey stuff, to use the technical term,” said planetary scientist Sean Solomon of Columbia University, who leads the MESSENGER team. Because the layer is relatively thin, it’s invisible to radar.
The MESSENGER team now thinks they have a good story to explain how these polar cold traps work. Every once in a while, a comet or asteroid hits Mercury and gets annihilated. The vaporized material either floats out into space or gets blasted away by the sun but any that finds its way into a permanently shadowed region will settle down. Molecule by molecule, water and other compounds build up inside the craters. Those that never see a ray of sunlight contain mostly clean water ice. But if even a tiny amount of light intrudes, it may heat up the water and cause it to recede below a layer of organic material.
“These look like really good results, and I think they are very convincing,” said planetary scientist Johannes Benkhoff from the Institute of Planetary Research in Germany, who is the lead scientist on the European Space Agency’s BepiColombo mission, which is expected to orbit Mercury in 2022. MESSENGER will provide many follow-up opportunities for this later mission, which will have its own neutron spectrometer to map the water ice regions with greater resolution.
In addition to being an astounding result, the finding can help scientists better understand the history of Earth. Mercury is a terrestrial planet like our own and the ice provides evidence for geologically recent delivery of water and carbon-rich material to the inner solar system from comets and asteroids. This process very likely happened billions of years in the past, when the Earth first formed, creating our planet’s oceans and possibly seeding them with the material to produce life.
“There’s now this record on Mercury, a place where we least expected to find it, of this process,” said Solomon. “It gives us a window to understanding this delivery system.”
Raw image of Saturn’s north polar hexagon, rings, and vortex
This photo looking down onto Saturn’s summer north pole was taken on November 27, 2012 from a distance of 361,000 kilometers through an infrared (CB2) filter. It has been filtered to reduce noise from cosmic ray hits and JPEG compression (top).
This view, looking down on Saturn’s north pole, was taken on November 27, 2012. You can see the hexagon surrounding Saturn’s north pole, as well as some of Saturn’s rings beyond the limb (bottom).
"I would request that my body, in death, be buried, not cremated, so that the energy content contained within it gets returned to the earth, so that flora and fauna can dine upon it, just as I have dined upon flora and fauna throughout my life."
Neil Degrasse Tyson