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Astronomers Find Ancient Earth-Sized Planets in Our Galactic Backyard

Posted date: 10:56 PM / comment : 0 , , , ,

Sun-like star with orbiting planets, dating back to the dawn of the Galaxy, has been discovered by an international team of astronomers.
At 11.2 billion years old, it is the oldest star with Earth-sized planets ever found and proves that such planets have formed throughout the history of the Universe.
The discovery, announced on 28 January (AEDT) in the Astrophysical Journal, used observations made by NASA's Kepler satellite. The scientific collaboration was led by the University of Birmingham and contributed to by the University of Sydney.
The star, named Kepler-444, hosts five planets smaller than Earth, with sizes varying between those of Mercury and Venus.
"We've never seen anything like this -- it is such an old star and the large number of small planets make it very special," said Dr Daniel Huber from the University's School of Physics and an author on the paper.
"It is extraordinary that such an ancient system of terrestrial-sized planets formed when the universe was just starting out, at a fifth its current age. Kepler-444 is two and a half times older than our solar system, which is only a youthful 4.5 billion years old.
"This tells us that planets this size have formed for most of the history of the universe and we are much better placed to understand exactly when this began happening."
Dr Tiago Campante, the research leader from the University of Birmingham said, "We now know that Earth-sized planets have formed throughout most of the Universe's 13.8-billion-year history, which could provide scope for the existence of ancient life in the Galaxy."
Together with their international colleagues the University's astronomy team used asteroseismology to determine the age of the star and planets. This technique measures oscillations -- the natural resonances of the host star caused by sound waves trapped within it.
They lead to miniscule changes or pulses in the star's brightness and allow researchers to measure its diameter, mass, and age. The presence and size of the planets is detected by the dimming that occurs when the planets pass across the face of the star. This fading in the intensity of the light received from the star enables scientists to accurately measure the sizes of the planets relative to the size of the star.
"When asteroseismology emerged about two decades ago we could only use it on the Sun and a few bright stars, but thanks to Kepler we can now apply the technique to literally thousands of stars. Asteroseismology allows us to precisely measure the radius of Kepler-444 and hence the sizes of its planets. For the smallest planet in the Kepler-444 system, which is slightly larger than Mercury, we measured its size with an uncertainty of only 100km," Dr Huber said.
"It was clear early on that we had discovered something very unusual because we had five planets orbiting a very bright star -- one of the brightest Kepler has observed. It is fantastic that we can use asteroseismology to date the star and determine just how old it is.
"In the case of Kepler-444 the planets orbit their parent star in less than 10 days, at less than one-tenth the Earth's distance from the Sun. Their closeness to their host star means they are uninhabitable because of the lack of liquid water and high levels of radiation. Nevertheless, discoveries like Kepler-444 provide important clues on whether a planet that is more truly comparable to Earth may exist. "We're another step closer towards finding the astronomers' holy grail -- an Earth-sized planet with a one year orbit around a star similar to our Sun."
A/c NASA, Astronomers using data from NASA's Kepler mission have discovered a planetary system of five small planets dating back to when the Milky Way galaxy was a youthful two billion years old.
The tightly packed system, named Kepler-444, is home to five planets that range in size, the smallest comparable to the size of Mercury and the largest to Venus. All five planets orbit their sun-like star in less than ten days, which makes their orbits much closer than Mercury's sweltering 88-day orbit around the sun.
Story Source:
The above story is based on materials provided by University of Sydney.

Read article on Science @ NASA

Journal Reference:
  1. J. Ireland, R. T. J. McAteer, A. R. Inglis. CORONAL FOURIER POWER SPECTRA: IMPLICATIONS FOR CORONAL SEISMOLOGY AND CORONAL HEATING. The Astrophysical Journal, 2014; 798 (1): 1 DOI: 10.1088/0004-637X/798/1/1

9 Things NASA has Helped Bring US

Posted date: 9:29 AM / comment : 0 ,



This is the 14th day of the US government shutdown and 97% of NASA is still furloughed. This seems like a good time to remind us all how much they've benefited society, technology and the economy over the years.

Star Found Shooting Water "Bullets". Stellar sprinklers may help irrigate cosmos, study suggests.

Posted date: 5:07 PM / comment : 0 , ,


An illustration of a protostar.
A star is born: Swirling gas and dust fall inward, spurring polar jets, shown in blue in this illustration.
Illustration courtesy NASA/Caltech 
Andrew Fazekas
Seven hundred and fifty light-years from Earth, a young, sunlike star has been found with jets that blast epic quantities of water into interstellar space, shooting out droplets that move faster than a speeding bullet.
The discovery suggests that protostars may be seeding the universe with water. These stellar embryos shoot jets of material from their north and south poles as their growth is fed by infalling dust that circles the bodies in vast disks.
"If we picture these jets as giant hoses and the water droplets as bullets, the amount shooting out equals a hundred million times the water flowing through the Amazon River every second," said Lars Kristensen, a postdoctoral astronomer at Leiden University in the Netherlands.
"We are talking about velocities reaching 200,000 kilometers [124,000 miles] per hour, which is about 80 times faster than bullets flying out of a machine gun," said Kristensen, lead author of the new study detailing the discovery, which has been accepted for publication in the journal Astronomy & Astrophysics.
Water Vanishes, Only to Reappear
Located in the northern constellation Perseus, the protostar is no more than a hundred thousand years old and remains swaddled in a large cloud—gas and dust from which the star was born.
Using an infrared instrument on the European Space Agency's Herschel Space Observatory, researchers were able to peer through the cloud and detect telltale light signatures of hydrogen and oxygen atoms—the building blocks of water—moving on and around the star.
After tracing the paths of these atoms, the team concluded that water forms on the star, where temperatures are a few thousand degrees Celsius. But once the droplets enter the outward-spewing jets of gas, 180,000-degree-Fahrenheit (100,000-degree-Celsius) temperatures blast the water back into gaseous form.
Once the hot gases hit the much cooler surrounding material—at about 5,000 times the distance from the sun to Earth—they decelerate, creating a shock front where the gases cool down rapidly, condense, and reform as water, Kristensen said.
Stellar Sprinkler Nourishes Galactic "Garden"
What's really exciting about the discovery is that it appears to be a stellar rite of passage, the researchers say, which may shed new light on the earliest stages of our own sun's life—and how water fits into that picture.
"We are only now beginning to understand that sunlike stars probably all undergo a very energetic phase when they are young," Kristensen said. "It's at this point in their lives when they spew out a lot of high-velocity material—part of which we now know is water."
Like a celestial sprinkler system, the star may be enriching the interstellar medium—thin gases that float in the voids between stars. And because the hydrogen and oxygen in water are key components of the dusty disks in which stars form, such protostar sprinklers may be encouraging the growth of further stars, the study says.
The water-jet phenomenon seen in Perseus is "probably a short-lived phase all protostars go through," Kristensen said.
"But if we have enough of these sprinklers going off throughout the galaxy—this starts to become interesting on many levels."

Week in science: Canine brains resemble humans' & others

Posted date: 8:58 PM / comment : 0 , , ,

Excerpts from science, technology, environment and health reports from around the web.

Source: Canines have lateralised brains—just like people
Sinister v dexterous. Commie v Tory. The difference between left and right carries more meaning to human beings than mere matters of handedness and symmetry. And so it is with man’s best friend as well. For in dogs, too, left and right signal different things. Specifically, it is in the way they wag their tails. And for dogs, like people, it is the left-hand side that is sinister.
The story started a few years ago when Giorgio Vallortigara of the University of Trento, in Italy, and his colleagues, established that dogs wag their tails to the right when they see something pleasant, such as a beloved human master, and to the left when they see something unpleasant, such as an unfamiliar dominant dog. What Dr Vallortigara did not establish then was whether such signals are meaningful to other dogs. Now, he and the team from the previous study have done just that.
Source: Exoplanet discovered to be Earth-sized and covered in lava
Astronomers have found that another world is quite similar to our own: It has a radius just 1.17 times and a mass only 1.9 times that of Earth. Though its size is familiar, it has the troubling problem of orbiting about 100 times closer to its star than our own planet.
That means surface temperatures on the planet, called Kepler-78b, range from 2,240 to nearly 5,000 degrees Fahrenheit. Kepler-78b is basically a planet of lava. The scorched world zips around its parent star, completing a year every eight and a half hours.
Source: NASA sends ISRO peanuts for Mars trip via Facebook
As ISRO’s scientists prepare themselves for a landmark-making launch of the Mars Orbiter Mission (MOM) on November 5, their counterparts in NASA, the U.S. space agency, have extended their good wishes for the mission by sending them some ‘lucky peanuts’.
The good wishes were posted on ISRO’s eight-day-old MOM Facebook page.
Source: Simulations help study impacts of aerosols over India
Scientists say that computer-aided simulations of seasonal dust emissions and transport using regional climate models (RegCM) can help overcome the lack of ground-based data on aerosols rising over the Indian sub-continent.
Aerosols are colloids of fine particles suspended in the air that come from natural sources or man-made activity and are known to impact the climate and human health.
Source: Reindeer eyes turn blue in winter, study finds
Reindeer may be best known for fictional Rudolph's glowing red nose, but now scientists find the animals can alter color elsewhere as well — the backs of their eyeballs change from gold in the summer to blue in the winter.
This change in color helps reindeer eyes capture more light during the dark winter months in the Arctic, scientists added.
Source: Building cars out of batteries isn’t as crazy as it sounds
The high cost and limited range of electric vehicles can make them a tough sell, and their costliest and most limiting component are their batteries.
But batteries also open up new design possibilities because they can be shaped in more ways than gasoline tanks and because they can be made of load-bearing materials. If their chemistries can be made safer, batteries could replace conventional door panels and other body parts, potentially making a vehicle significantly lighter, more spacious, and cheaper. This could go some way toward helping electric cars compete with gas-powered ones.

Luna 15 and Apollo 11: A Near-Miss on the Moon?

Posted date: 5:41 PM / comment : 0 ,

It was mid-day on July 21, 1969. Engineers at Mission Control in Houston were preparing for Apollo 11's departure from the moon. Neil Armstrong and Buzz Aldrin's excursion onto the moon's surface was over, and they were stowing equipment in preparation for liftoff early in the afternoon. Meanwhile, a Soviet probe, Luna 15, crash landed on the moon!

 Luna 15 was launched three days before the Apollo 11 lift-off. Its aim was to land on the lunar surface, collect rock samples, and return to Earth. If all went well, it could have arrived back on Earth the same day the astronauts came home: a small victory for the Soviets (whose Luna 2 spacecraft was the first human-made object to reach the moon, in 1959). But after several dozen orbits of the moon, the probe's landing didn't go as planned. It stopped transmitting four minutes into its descent, and crashed at Mare Crisium.
I was curious about how far the Luna crash was from the Apollo 11 Lunar Module. Mare Crisium is the "sea" directly north of Mare Tranquilltatis, site of Apollo 11's landing. According to Yahoo Answers (maybe not the most reliable source?), the two crafts were a little over 740 miles apart. 

Was the Apollo 11 mission ever in danger of a collision with Luna 15? Were the Soviets aiming to crash their probe into the Lunar Module? We know now that the answer to both questions was "no." But apparently back in 1969 NASA officials had some concerns. Astronaut Frank Borman put a call into one of the leaders of the Soviet space program, Dr. Mstislav Keldysh, asking him to confirm that the probe posed no threat to Apollo 11's mission. In what some describe as the very first instance of U.S.-Soviet cooperation in the space race, the Soviets released Luna 15's flight plan to NASA officials, allaying fears that it was on a collision course with the Lunar Module or the Command Module. 

During their mission, Armstrong, Aldrin, and Michael Collins were kept apprised of Luna 15's status. Apparently there were others tracking the craft as well. Astronomers at the University of Manchester Jodrell Bank radio telescope eavesdropped on Luna 15's final minutes. Their recordings were released in 2009; you can listen to a British scientist narrate the craft's crash here.

So the space race effectively ended that day. Americans were first to walk on the moon, hours before an unmanned Soviet landing failed. But, in the process, the U.S. and the U.S.S.R. first cooperated in space!

  1.  "Russian spacecraft landed on Moon hours before Americans". telegraph.co.uk. 4 July 2009. Retrieved 2009-11-15.
  2. Recording tracks Russia's Moon gatecrash attempt
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