THE LATEST FROM SPACE SCIENCE AND RESEARCH (D)


(BEING CONTINUED FROM  4/08/15)

TH)COMETS AND FORMATION OF LIFE

For the first time, scientists have directly detected a crucial amino acid and a rich selection of organic molecules in the dusty atmosphere of a comet, further bolstering the hypothesis that these icy objects delivered some of life’s ingredients to Earth.

The amino acid glycine, along with some of its precursor organic molecules and the essential element phosphorus, were spotted in the cloud of gas and dust surrounding Comet 67P/Churyumov-Gerasimenko by the Rosetta spacecraft, which has been orbiting the comet since 2014. While glycine had previously been extracted from cometary dust samples that were brought to Earth by NASA’s Stardust mission, this is the first time that the compound has been detected in space, naturally vaporized.

The discovery of those building blocks around a comet supports the idea that comets could have played an essential role in the development of life on early Earth, researchers said. [Photos: Europe’s Rosetta Comet Mission in Pictures]

The two-part Rosetta spacecraft is designed to orbit and land on the Comet 67P/Churyumov-Gerasimenko in November 2014. <a href="http://www.space.com/24333-rosetta-spacecraft-comet-landing-explained-infographic.html">See how the Rosetta spacecraft works in this Space.com infographic</a>.

The two-part Rosetta spacecraft is designed to orbit and land on the Comet 67P/Churyumov-Gerasimenko in November 2014. See how the Rosetta spacecraft works in this Space.com infographic.

Credit: by Karl Tate, Infographics Artist

“With all the organics, amino acid and phosphorus, we can say that the comet really contains everything to produce life — except energy,” said Kathrin Altwegg of the University of Bern in Switzerland, the principal investigator for the Rosetta mission’s ROSINA instrument.

“Energy is completely missing on the comet, so on the comet you cannot form life,” Altwegg told Space.com. “But once you have the comet in a warm place — let’s say it drops into the ocean — then these molecules get free, they get mobile, they can react, and maybe that’s how life starts.”

Getting a glimpse

Glycine, one of the simplest amino acids, is usually bound up as a solid, which means it’s difficult to detect from afar, Altwegg said.

While scientists have searched for glycine through telescopes in star-forming regions of the sky, the newly reported detection marks the first sighting of the compound in space. In this case, the orbiting Rosetta was close enough to pick up the glycine released by the comet’s dust grains as they heated up in the sun.

The study is a powerful confirmation of earlier, earth-bound detections of life’s building blocks in comet and meteor material.

“We know the Earth was pretty heavily bombarded both with asteroidal material and cometary material,” said Michael A’Hearn, a comet researcher at the University of Maryland who was not involved in the new study.

“There have been various claims of amino acids in meteorites, but all of them have suffered from this problem of contamination on Earth. The Stardust [samples] — which are from a comet, not an asteroid — are probably the least susceptible to the terrestrial contamination problem, but even there the problem is severe,” A’Hearn told Space.com. “I think they [Stardust] really did have glycine, but this is a much cleaner detection in many ways.”

Cooking up life

Amino acids form the basis of proteins, which are complexly folded molecules that are critical to life on Earth. Altwegg’s team searched for other amino acids around the comet as well, but located only glycine — the only one that can form without liquid water (as in the frigid reaches of space).

The glycine probably didn’t form on the comet itself, Altwegg said, but rather in the broad stretches of dust and debris that made up the solar system before planetary bodies formed.

“The solar system was made out of material which formed in a disk, in a solar nebula,” Altwegg said. “In these clouds, it’s pretty cold, so the chemistry you do there is catalytic chemistry on the dust surfaces. And these very small dust grains [1 micron in size] are very good to lead to organic chemistry. This is also done in the lab.” Earth itself was far too hot for similar delicate amino acids to survive its formation, Altwegg said; only the smallest solar system bodies stayed cold.

So glycine formed during that time could have provided a boost to newly forming life if it was delivered to Earth by comets.

“It’s not that it couldn’t have formed on Earth — it certainly could — it’s just that it didn’t have to,” A’Hearn said. “Basically, the Earth got a head start.”

Other, more complex amino acids require liquid water, and so would have likely formed on Earth itself, Altwegg said. This idea is supported by the fact that Rosetta has not identified any amino acids other than glycine near Comet 67P.

Phosphorus is also vital to life as we know it. Among other things, the element is a key constituent of DNA and adenosine triphosphate (ATP), a molecule that stores the chemical energy used by cells.

Rosetta is the first spacecraft to bring the right kind of instrument up close to a comet; future probes could examine other comets or even bring frozen samples back for analysis, to see how representative 67P is of comets in general.

But in the meantime, the team is still working on understanding all the organics they found and analyzing them further. “And I think the next step goes to the biochemists, how to make something meaningful out of this,” Altwegg said.

The discovery is also significant to researchers trying to understand the conditions of the early solar system, when the comet’s nucleus first came together, not to mention conditions when the early Earth was bombarded by similar comets.

“For astrobiology, it’s a very important measurement,” Altwegg said. “And it’s not only life on Earth; the material in comets has been formed in a protostellar cloud, and what could have happened here in our protostellar cloud could have happened everywhere in the universe.”

“Then you can ask yourself the question: How many Earths are there, how many evolved life or re-evolved life?” she added.

The new work was detailed in the journal Science Advances May 27.

Email Sarah Lewin at slewin@space.com or follow her @SarahExplains.

– See more at: http://www.livescience.com/54932-life-building-blocks-found-around-comet.html#sthash.Xuq22AmX.dpuf

SOURCE http://www.livescience.com/

I)Study reveals the galaxy is under pressure to make stars

Study reveals the galaxy is under pressure to make stars

The motions of interstellar gas (foreground) seen in contrast to the optical view of the Orion molecular cloud (background). Credit: Stephen Gwyn, Canadian Astronomy Data Centre/National Research Council of Canada (CNW Group/National Research Council Canada)

A new study led by Canadian astronomers provides unprecedented insights into the birth of stars. Using observations from the Green Bank Telescope in West Virginia and the Hawaii-based James Clerk Maxwell Telescope in the United States, astronomers from the National Research Council of Canada (NRC) have discovered that star formation is more regulated by pressure from their surroundings than previously thought.

The birth of stars occurs deep within dense concentrations of interstellar gas and dust—known as cores— when their internal support structure becomes overwhelmed. These cores typically contain several times the mass of the Sun over a region about 10,000 times the size of the Solar System. Cores are deeply embedded within molecular gas clouds which are located throughout our Milky Way Galaxy.

Although dust within cores hides the earliest stages of star formation from view of optical telescopes, observations with specialized radio telescopes can peer through the dust to study their dynamic nature. The Gould Belt Survey from the James Clerk Maxwell Telescope identified the locations, sizes, and masses of cores across the Orion A cloud while the Green Bank Ammonia Survey detected the motion of gas molecules within the clouds.

“By combining this data, we’ve learned that most Orion cores are gravitationally bound, and so they will likely one day collapse to form stars,” says Dr. Helen Kirk, the astronomer with the National Research Council who led the study. “Intriguingly, ambient material from the surrounding cloud appears to be squeezing the cores by an amount larger than the gravity of the cores themselves.”

Earlier analyses of cores often ignored the ambient cloud pressure, but this new work suggests that it is a key ingredient in understanding the futures of cores. “This suggests that clouds within our Galaxy are themselves likely under pressure to form stars,” Kirk concluded.

Provided by: National Research Council of Canada

SOURCE : http://phys.org/

IA)Signs of alien life on Mars could have been wiped out by space radiation: Scientists say finding ET may be harder than we think

  • Amino acids are potential signs of past life that might be found on Mars
  • But new research has shown they are unlikely to be on planet’s surface
  • They were probably destroyed by space radiation, according to study
  • Future missions will have to dig deeper into Mars’ surface to find clues

Mars is among a group of planets and moons in our solar system considered promising candidates for hosting, or having once hosted, alien life.

But signs of this life in the solar system may be harder to find than previously thought.

Any relics left over on the surface of the planet are likely to have been wiped out by powerful space radiation, according to new research.

Our neighbouring planet Mars could have been covered in vast salty oceans (artist's impression pictured) that would have been ideal for life to form. According to a new study, the signs of this life might be more difficult to find than previously thought, because of the harmful effects of space radiation 

 

Our neighbouring planet Mars could have been covered in vast salty oceans (artist’s impression pictured) that would have been ideal for life to form. According to a new study, the signs of this life might be more difficult to find than previously thought, because of the harmful effects of space radiation 

WHAT THE STUDY FOUND

Amino acids, the building blocks of proteins, are one of the signs researchers are hoping to find. 

Previous research suggested amino acids could survive for up to 1 billion years under Martian conditions – when looking at amino acids on their own.

The researchers mixed the amino acids with a kind of rock found on Mars and studied the effects of radiation.

They found ‘the destruction rate of amino acids in silicate powder mixtures is dramatically higher than in pure dry amino acid mixtures.’

Mars is considered two of the most likely places for signs of past life to be found in our solar system because it is the planet that most closely resembles our own.

The red planet once hosted vast oceans on its surface, which is considered one of the most vital properties necessary for life to thrive.

But new research is suggesting signs of this life might more difficult to find, because they could be destroyed by the harsh radiation in space more quickly than previously thought.

Amino acids, the building blocks of proteins, are one of the signs researchers are hoping to find. 

Previous research suggested amino acids could survive for up to 1 billion years under Martian conditions. 

But Dr Alexander Pavlov, space scientist at Nasa’s Goddard Space Flight Center in Maryland, and colleagues conducted new research and found the majority of amino acids were likely to be destroyed in 20 million years. 

The ‘search for the extinct life on Mars is based on the assumption that some original complex organic molecules would be able to survive for hundreds of millions – billions of years in the ancient Martian outcrops’ according to the study

WHAT ARE THESE COSMIC RAYS?

The Earth is constantly bombarded by high energy particles like protons, electrons and atomic nuclei. These particles make up the so-called ‘cosmic radiation’.

These ‘cosmic rays’ are electrically charged, and are hence strongly deflected by the interstellar magnetic fields that pervade our galaxy.

This means the path they have travelled through the cosmos to reach us is so random that we have no idea what made them, so they have baffled scientists for more than a century. 

The Earth’s thick atmosphere acts as a shield from the rays.

But modern Mars has a thin atmosphere and Europa has virtually no atmosphere at all. 

Both worlds are bombarded by high levels of radiation, which could spell doom for any fossils that may have once existed on the worlds’ surfaces.

The Earth is constantly bombarded by high energy particles like protons, electrons and atomic nuclei. These particles make up the so-called 'cosmic radiation'. These 'cosmic rays' are electrically charged, and are hence strongly deflected by the interstellar magnetic fields that pervade our galaxy

The Earth is constantly bombarded by high energy particles like protons, electrons and atomic nuclei. These particles make up the so-called ‘cosmic radiation’. These ‘cosmic rays’ are electrically charged, and are hence strongly deflected by the interstellar magnetic fields that pervade our galaxy

‘More than 80 percent of the amino acids are destroyed for dosages of 1 megagray, which is equivalent to 20 million years,’ Dr Pavlov said during a presentation at a conference, according toLive Science

‘If we’re going for ancient biomarkers, that’s a very big problem.’

Mars’ ocean is thought to have existed around 3.4 billion years ago, when life was first starting to form on our own planet. 

But Dr Pavlov’s team mixed the amino acids with rocky material similar to that found on Mars, and found all the amino acids were degraded by radiation in as few as 50 million years.

This means Mars rovers would have to dig deeper to find amino acids that might have been shielded from the radiation.

‘We are extremely unlikely to find primitive amino acid molecules in the top 1 metre [3.3 feet] [of the crust], due to cosmic rays,’ Dr Pavlov said. ‘It would be critical to provide missions with 2-metre [6.6 feet] drilling capabilities, or chose landing sights with freshly exposed rocks.’

Mars rovers like Nasa's Curiosity, shown, will have to dig deeper to find amino acids that might have been shielded from the radiation. Future missions would have to have 6.6 feet (2 metre) drilling capabilities, or chose landing sights with freshly exposed rocks, the researchers have said

Mars rovers like Nasa’s Curiosity, shown, will have to dig deeper to find amino acids that might have been shielded from the radiation. Future missions would have to have 6.6 feet (2 metre) drilling capabilities, or chose landing sights with freshly exposed rocks, the researchers have said

RADIATION ON EUROPA

A separate study focusing on Jupiter’s moon Europa also concluded the surface of the moon is an unlikely place for signs of life to survive.

Simulating the conditions on Europa’s surface, the researchers found the moon’s radiation dosages were comparable to those on Mars.

Simulations suggest microbes found in some of Earth’s harshest environments would survive no more than 150,000 years in the top 3.3 feet (1m) of Europa’s icy crust. 

A separate study focusing on Jupiter’s moon Europa also concluded the surface of the moon is an unlikely place for signs of life to survive.

Simulating the conditions on Europa’s surface, the researchers found the moon’s radiation dosages were comparable to those on Mars.

‘Radiation is going to play a major role at Europa in the top few meters — actually, dare I say, dozen meters — of Europa’s surface,’ said Luis Teodoro, a planetary scientist at Nasa’s Ames Research Center in California, speaking at the same conference.

He said his simulations suggest microbes found in some of Earth’s harshest environments would survive no more than 150,000 years in the top 3.3 feet (1 m) of Europa’s icy crust.

Organic biomarkers buried within 3.3 feet  (1 metre) of the surface would last only 1 to 2 million years, he said.

‘If we want to put a lander on the surface of Europa to check if life is there, we most likely are going to see something destroyed — mangled materials, mainly organics — from this huge dosage of radiation,’ he said.

With a liquid layer located just a few miles underground, the ground on Europa refreezes where an impact happens, creating a fractured terrain with young scars on its plains, as seen in this image

JUPITER’S ICY MOON EUROPA

Jupiter’s icy moon Europa is slightly smaller than Earth’s moon. 

Europa orbits Jupiter every 3.5 days and is tidally locked – just like Earth’s Moon – so that the same side of Europa faces Jupiter at all times.

It is thought to have an iron core, a rocky mantle and a surface ocean of salty water, like Earth. 

Unlike on Earth, however, this ocean is deep enough to cover the whole surface of Europa, and being far from the sun, the ocean surface is globally frozen over.

Many experts believe the hidden ocean surrounding Europa, warmed by powerful tidal forces caused by Jupiter’s gravity, may have conditions favourable for life. 

By ABIGAIL BEALL

SOURCE http://www.dailymail.co.uk/

(TO BE CONTINUED)

About sooteris kyritsis

Job title: (f)PHELLOW OF SOPHIA Profession: RESEARCHER Company: ANTHROOPISMOS Favorite quote: "ITS TIME FOR KOSMOPOLITANS(=HELLINES) TO FLY IN SPACE." Interested in: Activity Partners, Friends Fashion: Classic Humor: Friendly Places lived: EN THE HIGHLANDS OF KOSMOS THROUGH THE DARKNESS OF AMENTHE
This entry was posted in SCIENCE=EPI-HISTEME and tagged , , , , , , . Bookmark the permalink.

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s