SPACE - Search For Life

"To find life in the universe, a new initiative to help us hear the signals" PBS NewsHour 7/20/2015

Excerpt

SUMMARY:  Are we alone in the universe?  A new project called the Breakthrough Initiative may help scientists like Stephen Hawking get closer to the answer.  Tech investor Yuri Milner pledged $100 million to help survey one million of the closest stars to Earth for signals from other forms of intelligent life.  Gwen Ifill discusses the project with Andrew Siemion, director of the Berkeley SETI Research Center.

GWEN IFILL (NewsHour):  The search for signs of intelligent life in the universe may have been a fruitless one so far, but the effort got a major boost today with a new initiative from scientists Stephen Hawking and others.

Using some of the world’s biggest radio telescopes, the project will spend the next 10 years surveying a million of the closest stars to Earth, trying to find any signals from the 100 closest galaxies.  It’s called the Breakthrough Initiative and it’s funded by Russian billionaire and Silicon Valley tech investor Yuri Milner.  He’s pledged $100 million for the project.

Earlier today in London, physicist Stephen Hawking spoke to reporters about the eternal quest.

STEPHEN HAWKING, Physicist (through computer voice):  It’s time to commit to finding the answer to search for life beyond Earth.  The Breakthrough Initiatives are making that commitment.  We are alive.  We are intelligent.  We must know.

GWEN IFILL:  Andrew Siemion is director of the Berkeley SETI Research Center and is affiliated with the Breakthrough Initiative.  The acronym SETI stands for Search for Extraterrestrial Intelligence.

Andrew Siemion, thank you for joining us.

So, aside from Hollywood movies, how hard have we been looking for extraterrestrial life in the universe?

ANDREW SIEMION, Director, Berkeley SETI Research Center:  We have been looking pretty hard.

The modern radio search for extraterrestrial intelligence, this is the experiment to try to detect extraterrestrial technologies by their radio emissions, has been going on for about 55 years.

GWEN IFILL:  This $100 million investment that’s being made, how significant is that and what will it do?

ANDREW SIEMION:  It’s absolutely incredible.  And it’s coming at a very fortuitous time.

In the last couple of years, we have learned that at least 10 percent of the stars in our galaxy have an Earth-like planet, a planet about the size of the Earth that liquid water could exist on the surface.  And at the same time, our computing technology has advanced dramatically.  So we have the opportunity now to pair our knowledge of extrasolar planets and possibilities for life in the universe with incredible advances in computing technology to conduct the most sensitive search for extraterrestrial intelligence that we have ever undertaken in the history of humanity.

SPACE - Universe's Missing Mass Found?

This is for you techies out there.....

"Has the Missing 80% of the Universe’s Mass Been Found?" by Michael D. Lemonick, Time 4/5/2012

The universe has never made things easy; every time you look away, it becomes bigger, stranger, curiouser.  And that’s only the part we can see.  As you might have heard if you pay attention to these things (and will be distressed to learn if you don’t) up to 80% of the matter in the universe is simply missing.  The Milky Way spins so fast it would fly apart if the gravity of some invisible matter weren’t holding it together.  Clusters of galaxies, buzzing around one another like angry bees, would similarly fragment and disperse.  And when you run the gravitational numbers, the mysterious matter that keeps all that cosmic disintegration from happening should outweigh the familiar stuff by about four-to-one.

It was in the 1930s that astronomer Fritz Zwicky first proclaimed—to general skepticism—that what is now known commonly as dark matter must exist, surrounding most galaxies like a glass paperweight surrounds a butterfly.  But not only could physicists not detect the material, they couldn’t even agree on what they should be looking for.  Dark matter thus became as much an article of cosmological faith as of well-established theory.  Now, it appears, that faith may have been rewarded.  Just as researchers working at Europe‘s Large Hadron Collider last year announced that they had bagged the Higgs Boson, so did investigators this week reveal that they’ve found compelling evidence for a type of theorized particle known as a WIMP—for weakly interacting massive particle—and that at least one form of it may be the dark quarry they’ve been hunting for 80 years.

The new findings come from a team of physicists led by Samuel Ting, of the European Organization for Nuclear Research, relying on data gathered by the Alpha Magnetic Spectrometer (AMS), a detector delivered to the International Space Station in 2011.  The purpose of the AMS is to sift incoming cosmic rays—streams of high energy pouring in from outside the solar system—for unusual particles.  Dark matter particles, if they exist, might also get mingled into this cosmic flow, but theories suggest they’d be hard to spot.  They can pass through ordinary matter like it wasn’t there (billions could be streaming through your body as you read these words) and they’d be utterly invisible to any sort of telescope.

If we can’t detect dark matter itself, however, we might detect its byproducts.  Theorists think that when two dark matter particles meet out in space, they’ll occasionally, albeit not often, destroy each other in a tiny burst of energy.  That energy would then condense back into entirely different particles: an ordinary electron and its much rarer antimatter counterpart, a positron, which would go speeding away from each other in some random direction.

It’s these positrons that AMS detected — some 400,000 of them in the nearly two years it’s been in operation.  The number and energy of the positrons is consistent with what theorists would expect if dark matter really is smashing into itself throughout the Milky Way.  So is the fact that the positrons are hitting the detector from all directions, which it should if dark matter truly pervades the Milky Way.  Says, Jeremiah Ostriker, a Princeton astrophysicist who has been in the forefront of dark-matter theory since the 1970’s, “the AMS experiment may — just may — have detected [evidence of] dark matter decay.”

Ostriker’s caution, and that of the AMS team at a press conference on Wednesday, is understandable, and not just because the evidence is indirect—like spotting bear tracks instead of the bear.  Dark matter collisions, the scientists acknowledge, are not the only possible source of positrons.  They could be streaming off of spinning pulsars, the super-dense remnants of exploding stars that also pervade the Milky Way.  Their ubiquity would send positrons to us from all directions just the way dark matter would.  And even if the pulsars aren’t responsible, says, Ostriker, whose new book “Heart of Darkness” chronicles the history of dark-matter research since the very beginning, the positrons “could come from some other strange source” that astronomers haven’t even thought of yet.

It’s a good thing, therefore, that the AMS will keep operating for several more years, at least; the more positrons it can find, the firmer the case could become that their source really is dark matter, and physicists might even be able to reason backward and infer the nature of the original particle itself.   If AMS really does crack the mystery, Ting, who won a Nobel Prize in 1976 as co-discoverer of a particle known as the J/psi meson, could well snag another.  But he knows better than anyone that it’s a bit too early to start drafting the acceptance speech.  The universe may give up its secrets eventually—but it never, ever does so easily.

SPACE - Universe's First Objects Seen?

"Universe's 1st Objects After Big Bang Possibly Seen by NASA Telescope" by SPACE.com Staff, Space.com 6/8/2012

New observations from a NASA space telescope have spotted what may be the very first objects created in the universe in unprecedented detail, scientists say.

The faint objects, imaged in infrared light by NASA's Spitzer space telescope, might be hugely massive stars or black holes, but are too distant to see individually.

The Big Bang is thought to have kick-started the universe about 13.7 billion years ago. At first, the universe was too hot and dense for particles to be stable, but then the first quarks formed, which then grouped together to make protons and neutrons, and eventually the first atoms were created. After about 500 million years, the first stars, galaxies and black holes began to take shape.

The scientists can't confirm for sure that the objects they see date from the early universe, but say that's the most likely explanation.

"These objects would have been tremendously bright," Alexander "Sasha" Kashlinsky of NASA's Goddard Space Flight Center in Greenbelt, Md., said in a statement Thursday (June 7). "We can't yet directly rule out mysterious sources for this light that could be coming from our nearby universe, but it is now becoming increasingly likely that we are catching a glimpse of an ancient epoch."

Spitzer spotted these ancient structures after observing two patches of sky for more than 400 hours each. The telescope sees in infrared light, the long-wavelength range of the electromagnetic spectrum that's less energetic than optical light.

The researchers first removed all known stars and galaxies from the images. What was left over showed lumps of structure in a pattern consistent with how very distant objects are thought to cluster together.

The light spied by Spitzer has probably traveled for billions of years to reach us. It would have started out as optical or ultraviolet light, but over time stretched until it became infrared.

While Spitzer, which launched in 2003 and orbits the sun in an unusual Earth-trailing path, has made inroads in observing these objects, scientists are waiting for the James Webb Space Telescope to make major progress in understanding them.

James Webb, billed as the successor to the Hubble telescope, is an $8.8 billion infrared observatory due to launch in 2018.

"This is one of the reasons we are building the James Webb Space Telescope," said Glenn Wahlgren, Spitzer program scientist at NASA Headquarters in Washington, D.C. "Spitzer is giving us tantalizing clues, but James Webb will tell us what really lies at the era where stars first ignited."

The researchers report their findings in a paper in The Astrophysical Journal.

SPACE - Galaxy From Birth of Universe

(click for better view)


"Rare galaxy from 'dawn of time' photographed" by Tariq Malik (Space.com), MSNBC 12/22/2011

An ancient galaxy that formed just after the birth of the universe has been photographed by telescopes on Earth and in space, and is the brightest galaxy ever seen at such remote distances, astronomers say.

The blob-shaped galaxy, called GN-108036, is about 12.9 billion light-years away and appears as it existed just 750 million years after the universe began. The universe, for comparison, is about 13.7 billion years old.

But the sheer distance to the galaxy isn't the only thing to intrigue scientists. The galaxy is also creating stars at a furious pace, making it a rare cosmic find. NASA officials described the galaxy as shining from the "dawn of time," with star formation inside it occurring at a "shockingly high rate."

A photo of the rare galaxy released by NASA shows the object as a red blob surrounded by other bright galaxies.

"The discovery is surprising because previous surveys had not found galaxies this bright so early in the history of the universe," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz., in a statement announcing the find on Dec. 21.

"Perhaps those surveys were just too small to find galaxies like GN-108036. It may be a special, rare object that we just happened to catch during an extreme burst of star formation."

An international team of astronomers discovered galaxy GN-108036. It was initially spotted by Japan's Subaru telescope atop the volcano Mauna Kea in Hawaii, and its ultra-far distance was confirmed using the Keck Observatory, also on Mauna Kea. NASA's Hubble Space Telescope and infrared Spitzer Space Telescope were then used to take better images of the galaxy. The research is detailed in the Astrophysics Journal.

"We checked our results on three different occasions over two years, and each time confirmed the previous measurement," said study leader Yoshiaki Ono of the University of Tokyo.

Galaxies forming within the first few hundreds of millions of years after the Big Bang were much smaller than the ones astronomers see in later periods because they had not yet built up most of their bulk. So seeing a galaxy like GN-108036, which is small yet exceptionally bright and teeming with star formation, came as a shock. [The Universe to Now in 10 Easy Steps]

"We had never seen such a vigorously star-forming galaxy at a comparable distance until the discovery of GN-108036," Ono said.

Astronomers measure the distance to objects in space by measuring how much their light is stretched toward the red end of the light spectrum, a factor known as "redshift." The greater an object's redshift, the older and farther away it is, NASA officials explained.

GN-108036 has a staggering redshift of 7.2, one of the few objects known with a redshift larger than 7. Just two other objects have been confirmed to be older and more distant than GN-108036, NASA officials said.

The newfound galaxy is so ancient that it and others like it may have played a role in the transition from the so-called "dark ages" of the universe — a period before the first stars formed when a thick hydrogen fog permeated the cosmos — into the universe we see today.

"This was therefore a likely ancestor of massive and evolved galaxies seen today," said Bahram Mobasher, a team member from the University of California, Riverside.

SCIENCE - Ever Wonder What Black Holes Are?

For those who have a curious mind.....

"What Is a Black Hole, and How Are They Formed?" by JENNY MARDER, PBS Newshour 6/16/2011

It's been a big week for black holes. One study this week detected ancient black holes growing vigorously at the centers of their galaxies. Another found powerful gamma ray flashes from a giant black hole consuming a star.

A good time, we thought, for some basics on black holes. A black hole is an object that has collapsed under its own weight to a point, creating an object that is fantastically small, yet enormously dense. It sucks in everything it can absorb, and once formed, nothing, not even light, can escape its gravitational pull.

"They are the most voracious eaters in the universe," said Kevin Schawinski, a Yale university astrophysicist. "You can only go inside, and you can never come back out."

There are two main types of black holes. There are black holes born from the death of stars, which are roughly a few times the mass of our sun. These stars end their lives when the hydrogen fuel that makes up the star's interior burns off, causing the star to collapse.

Then, there are supermassive black holes, which range in mass from a few hundred thousand times the mass of our sun to a few billion times that mass, and exist at the center of galaxies. The black hole that lives at the center of the Milky Way is four million times the mass of our sun.

There are two schools of thought on how these supermassive black holes form. It's possible that they are seeded from the death of the earliest stars of the universe, which were massively large.

Another, recent theory involves discs of gas that swirl and funnel like a tornado. The early universe was filled with gas and radiation. In some spots, gravity caused gas to fall into halos of dark matter and form into gas discs, Priya Natarajan, a theoretical astrophysicist explained. Instabilities in these discs caused the swirling effect, in which the gas begins to funnel from the outside in.

The funneling can be likened to tornado formation. "The flow is like a tornado vortex," Natarajan said. "Very rapid, dramatic and violent. And it can happen quickly."

Scientists this week announced the discovery of a population of hyperactive, baby black holes growing with their host galaxies. They represent the oldest black holes ever found, and are possibly caused by this funneling phenomenon, said Natarajan, also one of the authors of the study. The black holes date back to 800 million years after the Big Bang -- that's 12.7 billion years ago.

This is extremely young in cosmic time. To put it in perspective, our universe is now 13.7 billion years old -- these black holes existed in its infancy.

The black holes are of the supermassive variety, though they haven't yet reached full mass. And data indicates that they are closely linked to the formation of their galaxies.

"We believe that the growth of black holes and the growth of galaxies are symbiotically linked," said Schawinski, also a study author. "We're pushing all the way to the very, very beginning of the universe and asking questions about how this relationship works and how it began."

The finding, released this week in the journal, Nature, is based on computer models using data from NASA's Chandra X-ray Observatory. Scientists pointed Chandra at the exact patch of sky where the Hubble Space Telescope had spotted baby galaxies, and observed it for 45 days.

They searched for X-ray emissions as markers to detect active, or feeding, black holes. As matter falls into dark holes, it emits energetic X-rays. Schawinski calls them "the final death scream."

It turns out more than 30 percent of distant galaxies contained black holes, but it took years to find them, because they were shrouded in cosmic dust. "It took seven years to detect the first signatures of growing supermassive black holes," said Ezequiel Treister, the study's lead author.

This is the first time that we're pinpointing when these black holes were forming and growing, and "we're also getting the first clues as to how these black holes grew," said Mitchell Begelman of the University of Colorado, Boulder, who was not involved in the study, but participated in a June 15 NASA presser on the subject.

Still in question, though, is how these black holes formed. Was it from massive discs of gas collapsing under their own gravity straight down into a black hole, or was it from the death of the first generation of stars, believed to be much more massive than the typical star?

The hope, scientists say, is to use Hubble and Chandra to push even farther back into the past to answer these questions, and figure out how these things formed.

This finding is not going to make anybody's life better, but it's important for human discovery and curiosity, Natarajan said. Cosmologists, she said, are the armchair explorers of our generation. And it's fun work, she added.

"I can't imagine doing anything else," she said. "I really can't imagine doing anything else."

COMMENT: You may have heard the term "Event Horizon" (there is a movie with the same title). It is "the point of no return" around a Black Hole, a spherical boarder. That is where the x-rays are given off.