Astronomers have discovered a baby blue galaxy that is the furthest away in distance and time - 13.1 billion years - that they’ve ever seen. Photo: Pascal Oesch and Ivelina Momcheva, NASA, European Space Agency via AP
A team of astronomers peering deep into the heavens have discovered the earliest, most distant galaxy yet, just 670 million years after the Big Bang.
Close-up of the blue galaxy
The findings, described in Astrophysical Journal Letters, reveal a surprisingly active, bright galaxy near the very dawn of the cosmos that could shed light on what the universe, now 13.8 billion years old, was really like in its young, formative years.
"We're actually looking back through 95 per cent of all time to see this galaxy," said study co-author Garth Illingworth, an astronomer at the University of California, Santa Cruz.
"It's really a galaxy in its infancy ... when the universe was in its infancy."
Capturing an image from a far-off light source is like looking back in time. When we look at the sun, we're seeing a snapshot of what it looked like eight minutes ago.
The same principle applies for the light coming from the galaxy known as EGS-zs8-1. We are seeing this distant galaxy as it existed roughly 13.1 billion years ago.
EGS-zs8-1 is so far away that the light coming from it is exceedingly faint. And yet, compared with other distant galaxies, it is surprisingly active and bright, forming stars at roughly 80 times the rate the Milky Way does today.
This precocious little galaxy has built up the mass equivalent to about 8 billion suns, more than 15 per cent of the mass of the Milky Way, even though it appears to have been in existence for a mere fraction of the Milky Way's more than 13 billion years.
"If it was a galaxy near the Milky Way [today], it would be this vivid blue colour, just because it's forming so many stars," Illingworth said.
One of the many challenges with looking for such faint galaxies is that it's hard to tell if they're bright and far, or dim and near. Astronomers can usually figure out which it is by measuring how much that distant starlight gets stretched, "redshifted", from higher-energy light such as ultraviolet down to optical and then infrared wavelengths. The universe is expanding faster and faster, so the further away a galaxy is, the faster it's going, and the more stretched, or "redder", those wavelengths of light will be.
The astronomers studied the faint light from this galaxy using NASA's Hubble and Spitzer space telescopes. But EGS-zs8-1 seemed to be too bright to be coming from the vast distances that the Hubble data suggested.
To narrow in, they used the MOSFIRE infrared spectrograph at the Keck I telescope in Hawaii to search for a particularly reliable fingerprint of hydrogen in the starlight known as the Lyman-alpha line. This fingerprint lies in the ultraviolet part of the light spectrum, but has been shifted to redder, longer wavelengths over the vast distance between the galaxy and Earth.
It's a dependable line on which to base redshift (and distance) estimates, Illingworth said - and with that settled, the team could put constraints on the star mass, star formation rate and formation epoch of this galaxy.
The telltale Lyman-alpha line also reveals the process through which the universe's haze of neutral hydrogen cleared up, a period called the epoch of reionisation. As stars formed and galaxies grew, their ultraviolet radiation eventually ionised the hydrogen and ended the "dark ages" of the cosmos.
Early galaxies-such as EGS-zs8-1 - are "probably the source of ultraviolet radiation that ionised the whole universe", Illingworth said.
Scientists have looked for the Lyman-alpha line in other distant galaxies and come up empty, which might mean that their light was still being blocked by a haze of neutral hydrogen that had not been ionised yet.
But it's hard to say with just isolated examples, Illingworth pointed out. If scientists can survey many galaxies from different points in the universe's very early history, they can have a better sense of how reionisation may have progressed.
"We're trying to understand how many galaxies do have this line - and that gives us some measure of when the universe itself was reionised," Illingworth said.
"One [galaxy] is interesting, but it's when you have 50 that you can really say something about what galaxies were really like then." As astronomers push the limits of current telescopes and await the completion of NASA's James Webb Space Telescope, set for launch in 2018, scientists may soon find more of these galaxies even closer to the birth of the universe than this new record breaker.
"You don't get to be record holder very long in this business," Illingworth said, "which is good because ultimately we are trying to learn about the universe. So more is better."
April 4, 2015 / Greg Giles / Comments Off on Science of frustrated magnets: Hall Effect experiment reveals clues to their discontent
Excerpt from thewestsidestory.netA scientific study carried out in Princeton has brought about the discovery of unlikely properties in materials called frustrated magnets using the Hall Effect.Hall Effect is the property of magnetic fields having inf...
Excerpt from historicmysteries.com By Shelly Barclay The Tarim Mummies or the Mummies of Xinjiang are mysterious mummies that were discovered in the foothills of the Tian Shan Mountains in China. What is so mysterious about them is that some of them date back to roughly 4,000 years ago, a time when it was thought that there were no westerners in that area. However, there must have been, because the Tarim mummies are Caucasian. Not only that, but they wear similar garments and share similar burial practices of some European countries.
The first of the Tarim mummies was discovered by Wang Binghua in 1978. Wang had been searching for ancient settlements along in the northeast of Xinjiang when a local man directed him to Quizilchoqa. It was there that Wang uncovered the first mysterious Tarim mummy. Over time, these mummies were discovered in four different sites in the Tarim Basin area. More than one hundred of them have been uncovered so far.
The Tarim mummies are unusually well preserved. This is interesting because the people who buried them did not practice mummification. The sites where these mummies have been found, lie on the edges of the Taklamakan Desert. When these ancient people buried their dead, the hot climate and rocky soil helped to keep the deceased’s body preserved, though it should have decomposed hundreds of years ago. Some of these corpses rival the Ancient Egyptian mummies in their extraordinary preserved state. Another very strange thing about the Tarim mummies is the attire in which they were buried. If the fact that some of them had blond hair and blue eyes hadn’t given away the fact that they were westerners that had settled in what is now Xinjiang, the clothing they wore when they were buried would have.
One of the mummies, the Yingpan Man, was six feet six inches tall and wore a red tunic with gold embroidery. He also wore a gold foil burial mask. This burial clothing is far more indicative of western influence than of Eastern. Other Tarim mummies have also been found wearing decidedly western clothing. One of the oddest bits of clothing found any of these mummies are the flat-brimmed pointy “witch hats” that were discovered on the “Witches of Subeshi.”
Researchers have been able to decipher a number of things about the people who buried these mummies since their discovery. This is largely due to the work of Dr. Victor Mair, the man who brought the Tarim mummies into the public eye. It is known that the ancient people rode horses, used chariots and had at least some medical knowledge. One of the Tarim mummies was found with evidence of a surgical wound on its neck, which had been sutured at some point.
Since the discovery of the caucasian-featured Tarim mummies in Xinjiang, scientists have been trying to uncover links between the ancient people who buried these mummies and modern citizens of the area. Thus far, several links have been discovered and hypothesized, but it is difficult to make them public or credible because of political unrest in the area. Nonetheless, there are many people who are certain that the Tarim mummies represent the first Caucasians to settle in the area. If this is fact, then it will mean that western man settled in the area roughly one thousand years before scientists had previously thought they did.
The canonical Bible is filled with mysterious characters, many of whom drop in for a cameo, do their thing, and then slide out, never to be heard from again. Some are merely extras, but some have a contextual presence that begs further examination. And some are, well, just weird.
Probably the single most mysterious figure in the Bible, Melchizedek was a priest-king of Salem (later known as Jerusalem) in the time of Abram (Abraham), suggesting a religious organization, complete with ritual and hierarchy, that predated the Jewish nation and their priestly lineage from the tribe of Levi. He is only portrayed as active in one passage, although he is alluded to once in Psalms, and several times in the New Testament’s Epistle to the Hebrews. Some Jewish disciplines insist that Melchizedek was Shem, Noah’s son. He is thought of, in Christian circles, as a proto-messiah, embodying certain traits later given to Christ. New Testament writings assert that Christ was “a priest forever in the order of Melchizedek,” indicating an older and deeper covenant with God than the Abrahamic-Levite lineage. Hebrews 7, though presents him in a more unusual light. In verses 3 and 4: “Without father, without mother, without descent, having neither beginning of days, nor end of life; but made like unto the Son of God; abideth a priest continually. Now consider how great this man was, unto whom even the patriarch Abraham gave the tenth of the spoils.” Not only do these verses grant Melchizedek a hierarchical level above the most important Jewish patriarch, they assign him mystical qualities. Some take this to mean an earlier incarnation of Christ. Others see it as an ancient manifestation of the Holy Spirit. His identity, role, and theological function have long been debated. The paucity of scriptural references have added to the mystery, making him a somewhat spectral figure. As such, newer spiritual traditions, as well as New Age quacks, have taken liberties with his persona. Gnostics insisted he became Jesus, and he is cited as a high-level priest in Masonic and Rosicrucian lore. Joseph Smith wrote that he was the greatest of all prophets, and Mormons still trace their priesthood back to him. The Urantia, a 20th-century pseudo-Bible that claims to merge religion, philosophy, and science, insists he’s the first in an evolutionary succession of deification manifestations, with Abraham being his first convert. There is even a school of thought that Melchizedek is a title or assumed character name, sort of a theological 007, played by a series of Judeo-Christian James Bonds.
The lore of Melchizedek is confusing but deep and fascinating. Apocryphal books give us more details, some cryptic, some relatively mundane. The Second Book of Enoch is particularly informative, insisting Melchizedek was born of a Virgin. When his mother Sophonim (the wife of Noah’s brother Nir) died in childbirth, he sat up, clothed himself, and sat beside her corpse, praying and preaching. After 40 days, he was taken by an archangel to the Garden of Eden, protected by angels and avoiding the Great Flood without passage on Uncle Noah’s ark.
9 Cain’s Wife
Cain was, according to Genesis, the first human ever born. He later killed his younger brother Abel in a hissy fit over his sacrifice of meat being more favored than Cain’s sacrificial fruit basket. God put a mark on Cain and cursed the ground he farmed, forcing him into a life as a wandering fugitive.
That part of the story is fairly well known. Later, though, we read that he settled in the Land of Nod, and, all of a sudden, he has a wife. Absolutely nothing else is mentioned about her. We don’t even know where she came from. In fact, the question of where Cain got his wife, when his immediate family were apparently the only people in the world, has sent many a perceptive young Sunday schooler down the road of skepticism.
Some have posited a mysterious other tribe of people, maybe created after Adam and Eve, maybe even another race or species. But the standard response is that Adam and Eve had many other sons and daughters to populate the Earth. The only way to keep the human race going would be to mate with siblings, nieces, nephews, and cousins.
In fact, though the Holy Bible is silent on her identity, the apocryphal Book of Jubilees tells us exactly who was Cain’s wife: his sister Awan, who bore his son Enoch.
8 Joseph Barsabbas
After Judas Iscariot turned in his resignation by selling out his boss, Jesus’s disciples rushed to fill the open position and bring the number back up to a more theologically apt 12. The remaining disciples, including the newly convinced Thomas, looked over the candidates from the 120 or so adherents who followed Jesus. Then they cast lots to pick who would fill the position.
It went to Matthias, a fairly mysterious character himself. We don’t know where he came from or his previous occupation. Some think he was actually the diminutive Zacchaeus, the tax collector who climbed a sycamore tree to get a better glimpse of Jesus’s ride on the donkey. The man who lost out was Joseph Barsabbas, also known as Joseph Justus. We know nothing solid about him, even less than we know about Matthias. There is, however, one bit of interesting speculation. A list of names presented in Mark 6:3 includes some of Christ’s earliest and most loyal adherents. One of these is a man named Joses, and another is James the Just. Biblical scholar Robert Eisenman suggests that James carried on Jesus’s work, and the writer of the Book of Acts assigned him an alias to minimize his importance.
7 The Beloved Disciple
In the Gospel of John, several references are made to “the disciple whom Jesus loved.” This particular favorite is present at the Last Supper, the crucifixion, and after the resurrection. The writer of the Gospel of John even states that the testimony of this disciple is the basis for the text. But there is considerable debate over the identity of this mystery figure. The most obvious nominee is John the Apostle, one of Christ’s inner circle of 12 and the namesake of the Gospel. But none of the 12 apostles were present at the crucifixion, so that crosses him off the list. Lazarus, resurrected by Christ, is also considered. He seems to have been present at the cited events and is referred to specifically, in the story of His death and resurrection, as “he whom Thou lovest.” Mary Magdalene, Judas, Jesus’s brother James, or an unnamed disciple, possibly even a Roman or governmental official, have all been considered. There is even a school of thought that John is an interactive gospel, with the reader being the beloved disciple.
6 Simon Magus
“Simony” is the selling of church position or privilege. It is named for Simon Magus, or Simon the Magician, who makes only a brief appearance in the Bible, in Acts 8:9–24. Simon has since become synonymous with heretical thought, and religious exploitation. He is presented as a powerful magician with a large following of in Samaria, who converts to Christianity and wishes to learn from apostles Peter and Phillip. When he sees the gifts of the Holy Spirit, including speaking in tongues and an ecstatic spiritual state, he offers the men money if they will give him the secret to passing these gifts to others. They are not amused. Apocryphal texts reveal quite a bit more, like his alleged ability to levitate and even fly, emphasizing that he was something akin to a cult leader in his hometown. It is suggested that his conversion is more for economic purposes than spiritual, and he set himself up as a messianic figure himself, competing for the Jesus dollar with his own homespun theology. He is thought by some to be a founder of Gnosticism, a patchwork of various religious systems that relied heavily on Judaic and Christian symbolism.
Not unlike Simon Magus, Onan’s brief appearance inspired a name for a particular action. He was the second son of Abraham’s grandson Judah, the patriarch and namesake of one of the 12 tribes of Israel. His older brother, Er (yes, just “Er”) was “wicked in the sight of the Lord,” so God killed him. What he did to deserve such an execution remains a mystery. Tradition at the time dictated that Er’s widow, Tamar, become Onan’s wife. Onan had to impregnate her to keep the lineage alive, but he was not as wild about the idea. Maybe it was the thought of impending fatherhood, or Tamar just wasn’t his type. So, taking matters into his own hands, he committed the first recorded act of coitus interruptus. Or, as Genesis 38:9 so poetically put it: “And Onan knew that the seed should not be his; and it came to pass, when he went in unto his brother’s wife, that he spilled it on the ground, lest that he should give seed to his brother.” God was displeased and slew Onan. The whole tale gets even more sordid. Onan had a younger brother, Shelah. Customarily, he would have been next in line to impregnate Tamar, but Judah forbade it. Tamar, rather than graciously accepting forced spinsterhood, seduced Judah and (became pregnant) by the old man. Judah fathered twins Zerah and Perez, the latter of whom was listed by Matthew as an ancestor of Jesus’s earthly father Joseph... Some have even suggested that Onan’s death warns that sex is meant only for purposes of reproduction, and not for pleasure.
Nicodemus was a member of the Sanhedrin, a council of men who ruled on Jewish law and governance. He became a friend, follower, and intellectual foil for Jesus, whose egalitarian teachings often ran counter to the Sanhedrin’s rigid decrees. He was also a Pharisee, a leader within the Jewish community who toadied up to the Roman government at the time of Christ’s arrest and subsequent crucifixion. He is mentioned three times in the New Testament, all in the Gospel of John. He subtly defends Jesus as the Pharisees discuss His impending arrest. Later, he helps prepare Jesus’s body for burial, indicating he had become an adherent to Christ and His teachings. The first time he is mentioned, however, is in dialogue with Jesus, and these conversations reveal some of the most important aspects of Christian theology, such as the notion of being “born again” and the most famous reference to the divinity of Christ, John 3:16: “For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.” This detailed conversation explores the divide between the Old Covenant’s dogmatic and exclusive Jewish Law and the New Covenant’s spiritually inclusive concepts. But for a vital contributor to such an important passage of the New Testament, Nicodemus remains a mysterious figure. Some scholars have suggested he may be Nicodemus ben Gurion, a Talmudic figure of wealth and mystical power. Christian tradition suggest he was martyred, and he is venerated as a saint. His name has come to be synonymous with seekers of the truth and is used as a character in many works of biblically inspired fiction.
3 James The Just
He is considered, next to Paul and Peter, the most important apostolic figure in the Church’s history. The Book of Acts specifically names him the head of the Christian church in Jerusalem, and he is frequently cited, both scripturally and apocryphally, as being consulted by both Paul and Peter. So who is he? Traditionally, he is thought of as Jesus’s brother (or, more precisely, His half-brother). Jesus is listed, in the Gospels, as having siblings, some younger than Him. One was named James. But James was a common name, and there are several mentioned in the Bible. Two of the 12 disciples were named James, but both are listed as having different fathers than Jesus, and neither went on to become James the Just. James the son of Zebedee went on to be known as James the Great, and James the son of Alphaeus was called James the Less. It is known that he was a contemporary of Jesus, although he seems to have had no real inner-circle status during Christ’s ministry. The apocryphal Gospel of Thomas says Christ Himself designated James to lead the movement upon His death. The Apostle Paul initially seems respectful, even subservient, to “James the Lord’s brother,” calling him a “pillar” of the movement, even though he was later to disagree with him on matters of doctrine. Some, though, have suggested the “brother” designation was spiritual, rather than physical. St. Jerome, among others, suggested that the doctrine of perpetual virginity indicated James could be a cousin, which, given the tribal associations and clannishness of the Jewish community of the time, seems valid. Such a relationship would indicate a certain social proximity without necessarily being a true sibling.
2 Simon The Zealot
Of Christ’s 12 disciples, none are more mysterious than Simon the Zealot. His name was meant to differentiate him from Simon Peter and has come to symbolize, for some, that he was a member of a similarly named political movement that advocated Jewish defiance to Roman law. Some have speculated that he acted, within Christ’s inner circle, as a political adviser. His presence then indicated that Jesus had a revolutionary political agenda. The truth is much less exciting. The “Zealot” movement did not take place until long after the time that Christ would have given Simon his sobriquet, and there has never been any serious evidence that Simon, despite the designation, was a political radical. The name, and the word upon which it is based, did not take on those aggressive undertones until the movement itself was in full swing. More than likely, Simon was given his name because of intense spiritual devotion, rather than any radical political stance. Nothing else is known of him, at least not with any surety. The Catholic Encyclopedia mentions him as possibly being a brother or cousin of Jesus, with no real evidence. The Eastern Orthodox tradition says he developed his zeal when Jesus attended his wedding and changed water into wine. Some legends say he was martyred; the philosopher Justus Lipsius somehow got it into his head that he was sawed in half.
Cited twice specifically, but alluded to frequently in general terms, the Nephilim were a race of violent giants that lived in the pre-Flood world at the same time as humanity. Were they, as some suggest, the offspring of demons and human women? Fallen angels themselves? Or simply the descendants of Seth mentioned in the Dead Sea scrolls, a tribe of cranky cases cursed by God for their rebelliousness? Regardless, they evolved and became known by other names, like the Raphaim, and frequently battled humans for land and power. The most storied of them was Og, the King of Bashan. He was killed, along with his entire army, and his kingdom was ransacked. All of the survivors—men, women, and children—were put to death, and the strongest and most powerful line of Nephilim descendants was eliminated. Some Nephilim bloodlines continued to do battle with the Israelites, though they were becoming less powerful and dying out. One tribe, the Anakim, allied themselves with the human tribes in Philistia. Goliath was thought to have been one of the last few descendants of the Nephilim. Goliath’s height is given in the earliest manuscripts as 275 centimeters (9′). That’s hardly as awe-inspiring as the creature laying in Og’s bed, which measured, according to Deuteronomy, 400 centimeters (13′ 6″). That’s basically Yao Ming sitting on Shaquille O’Neal’s shoulders. Biblically, descendants of the Nephilim could not have survived the Flood, even though Og and other giants are post-Flood figures. Some biblical literalists have attributed their later existence to the descendants of Noah’s family hooking up, once again, with demons. Or, being fallen angels and not human, they did survive the flood. Jewish tradition gets deeper into information about the Nephilim and their descendants, going against the grain of the biblical account. It tells of Og booking passage on the Ark by promising to act as a slave to Noah and his family. Other accounts have him hanging on to the side of the Ark and riding the flood out rodeo-style.
Excerpt from news.discovery.com One of the least likely places you might think astronomers would learn about ancient supernovae is at the bottom of the ocean, but in new research scientists have done just that.
Through the careful analysis of ocean sediment, tiny particles that originated from deep space have settled on the seabed, locking the chemical secrets to supernova processes that would have otherwise remained a mystery. “Small amounts of debris from these distant explosions fall on the earth as it travels through the galaxy,” said lead researcher Anton Wallner, of the Australian National University. “We’ve analyzed galactic dust from the last 25 million years that has settled on the ocean and found there is much less of the heavy elements such as plutonium and uranium than we expected.”
Supernovae are powerful explosions triggered when massive stars reach the ends of their lives. During these powerful events, many elements are forged, including elements that are essential for life to thrive — such as iron, potassium and iodine.
Wallner and his team studied samples of sediment from the bottom of a stable area at the bottom of the Pacific Ocean. But when measuring the quantities of plutonium-244, a radioisotope that is produced by supernovae, they found something strange in their results — there was 100 time less plutonium-244 than predicted.
Plutonium-244 has a half-life of 81 million years, making it an excellent indicator of the number of supernovae that have exploded nearby in recent galactic history. “So any plutonium-244 that we find on earth must have been created in explosive events that have occurred more recently, in the last few hundred million years,” said Wallner. But the fact that there is less recent deposition of the heaviest of elements, despite the fact that we know supernovae have erupted nearby, suggests a different formation mechanism may be responsible for plutonium-244 and elements like it.
“It seems that these heaviest elements may not be formed in standard supernovae after all,” concludes Wallner. “It may require rarer and more explosive events such as the merging of two neutron stars to make them.”
In the hunt for extraterrestrial life, scientists started by searching for a world orbiting a star just like the sun. After all, the steady warmth of that glowing yellow ball in the sky makes life on Earth possible.
But as astronomers continue to discover thousands of planets, they’re realizing that if (or when) we find signs of extraterrestrial life, chances are good that those aliens will orbit a star quite different from the sun—one that’s redder, cooler, and at a fraction of the sun’s size and mass. So in the quest for otherworldly life, many astronomers have set their sights on these small stars, known as red dwarfs or M dwarfs.
At first, planet-hunting astronomers didn’t care so much about M dwarfs. After the first planet outside the solar system was discovered in 1995, scientists began hunting for a true Earth twin: a rocky planet like Earth with an orbit like ours around a sun-like star. Indeed, the search for that kind of system drove astronomers through most of the 2000s, says astronomer Phil Muirhead of Boston University.
But then astronomers realized that it might be technically easier to find planets around M dwarfs. Detecting another planet is really hard, and scientists rely on two main methods. In the first, they look for a drop in a star’s brightness when a planet passes in front of it. In the second, astronomers measure the slight wobble of a star, caused by the gentle gravitational tug of an orbiting planet. With both of these techniques, the signal is stronger and easier to detect for a planet orbiting an M dwarf. A planet around an M dwarf also orbits more frequently, increasing the chances that astronomers will spot it.
M dwarfs got a big boost from the Kepler space telescope, which launched in 2008. By staring at small patch of the sky, the telescope searches for suddenly dimming stars when a planet passes in front of them. In doing so, the spacecraft discovered a glut of planets—more than 1,000 at the latest count—it found a lot of planets around M dwarfs. “Kepler changed everything,” Muirhead said. Because M-dwarf systems are easier to find, the bounty of such planets is at least partly due to a selection effect. But, as Muirhead points out, Kepler is also designed to find Earth-sized planets around sun-like stars, and the numbers so far suggest that M-dwarfs may offer the best odds for finding life.
“By sheer luck you would be more likely to find a potentially habitable planet around an M dwarf than a star like the sun,” said astronomer Courtney Dressing of Harvard. She led an analysis to estimate how many Earth-sized planets—which she defined as those with radii ranging from one to one-and-a-half times Earth’s radius—orbit M dwarfs in the habitable zone, the region around the star where liquid water can exist on the planet’s surface. According to her latest calculations, one in four M dwarfs hosts such a planet.
That’s higher than the estimated number of Earth-sized planets around a sun-like star, she says. For example, an analysis by astronomer Erik Petigura of UC Berkeley suggests that fewer than 10 percent of sun-like stars have a planet with a radius between one and two times that of Earth’s.
This illustration shows Kepler-186f, the first rocky planet found in a star’s habitable zone. Its star is an M dwarf. NASA Ames/SETI Institute/JPL-Caltech
M dwarfs have another thing going for them. They’re the most common star in the galaxy, comprising an estimated 75 percent of the Milky Way’s hundreds of billions of stars. If Dressing’s estimates are right, then our galaxy could be teeming with 100 billion Earth-sized planets in their stars’ habitable zones.
To be sure, these estimates have lots of limitations. They depend on what you mean by the habitable zone, which isn’t well defined. Generally, the habitable zone is where it’s not too hot or too cold for liquid water to exist. But there are countless considerations, such as how well a planet’s atmosphere can retain water. With a more generous definition that widens the habitable zone, Petigura’s numbers for Earth-sized planets around a sun-like star go up to 22 percent or more. Likewise, Dressing’s numbers could also go up. Astronomers were initially skeptical of M-dwarf systems because they thought a planet couldn’t be habitable near this kind of star. For one, M dwarfs are more active, especially during within the first billion years of its life. They may bombard a planet with life-killing ultraviolet radiation. They can spew powerful stellar flares that would strip a planet of its atmosphere.
And because a planet will tend to orbit close to an M dwarf, the star’s gravity can alter the planet’s rotation around its axis. When such a planet is tidally locked, as such a scenario is called, part of the planet may see eternal daylight while another part sees eternal night. The bright side would be fried while the dark side would freeze—hardly a hospitable situation for life.
But none of these are settled issues, and some studies suggest they may not be as big of a problem as previously thought, says astronomer Aomawa Shields of UCLA. For example, habitability may depend on specific types and frequency of flares, which aren’t well understood yet. Computer models have also shown that an atmosphere can help distribute heat, preventing the dark side of a planet from freezing over.
This was a great year for dinosaurs. Dreadnoughtus, "Jar Jar Binks," and a swimming Spinosaurus all made headlines — and 2015 could hold even more surprises.
It wasn't always like this. From 1984 to 1994, there were about 15 new dinosaur species named per year. This year, nearly one species was discovered every week.
"We're absolutely in a golden age of dinosaur discovery," David Evans, who oversees dinosaur research at the Royal Ontario Museum, told NBC News. "It is probably a better time to be a dinosaur paleontologist now than any other time in the last century."
The 'Jurassic Park' effect
When it comes to finding dinosaurs in the dirt, paleontologists are using the same tools that they were 30 years ago. Satellite images might give them a better view of dig sites, but for the most part the process has not changed much.
So why are there so many dinosaur discoveries these days? More people are looking for them. Evans estimates that the number of dinosaur paleontologists has more than quadrupled in the last 30 years.
Every paleontologist interviewed for this story pointed to one catalyst for the paleontology boom: Steven Spielberg's 1993 blockbuster "Jurassic Park."
"It put the most lifelike, scientifically accurate dinosaurs ever on the big screen," Evans said. "That helped the public moved beyond the classical view of dinosaurs as slow, dim-twitted creatures."
Famed Montana State University paleontologist Jack Horner admits he has a special affection for the film. He served as scientific adviser for the original "Jurassic Park" and was the inspiration for Dr. Alan Grant, the movie's protagonist. He also consulted on the upcoming "Jurassic World" starring Chris Pratt.
"'Jurassic Park' attracted an incredible number of people to the field," Horner told NBC News. "I'm hoping that we put together something cool with 'Jurassic World' that people will really like and get more children interested in paleontology."
Increased interest led to increased paleontology budgets for museums and universities, Evans said. That has made a big difference in places like China and Argentina, relatively unexplored areas where a new generation of paleontologists has unearthed most of the recent headline-grabbing discoveries.
"The number of dinosaur researchers is much higher now than in the '90s," Thomas Holtz, a vertebrate paleontologist at the University of Maryland, told NBC News. "Anytime you are exploring a region and a slice of time that hasn't been sampled before, chances are that everything you are finding is new."
2014 and beyond
Some of the biggest discoveries of the year were not new species. Instead, they were more complete fossils of dinosaurs the scientific community knew very little about.
Take Spinosaurus, a massive carnivore that was even bigger than Tyrannosaurus rex. While its teeth indicated it ate fish, scientists were divided on whether it roamed the land and water looking for prey.
This year, the matter was settled. A new paper showed that the dinosaur's unique body structure — tiny hind limbs, dense bones, crocodile-like receptors in its snout — was best suited for the water and caused it to waddle on land.
"That was probably the most significant find of the year," Horner said.
There were other big discoveries in 2014. Dreadnoughtus fossils discovered in Argentina belonged to a creature that measured 85 feet (26 meters) long and weighed about 65 tons (59 metric tons), or about as much as a dozen elephants.