Astronomy

Astronomers discover radio signal from galaxy billions of light-years away, report says

Canadian astronomers have reportedly discovered a repetitive radio signal some 2.5 billion light-years away from Earth — only the second example known to mankind. A telescope in British Columbia, otherwise known as Canadian Hydrogen Intensity Mapping Experiment (CHIME), detected 13 pulses — or fast radio bursts (FRBs) — in July and August, according to a Monday report from Nature, a British scientific journal. The findings were announced by Deborah Good, an astronomer at the University of British Columbia in Vancouver, at a meeting of the American Astronomical Society in Washington on Wednesday. “Look! We see FRBs,” she said of the cosmic flashes, which remain a mystery to astronomers. Before they were spotted over the summer, astronomers reportedly found between 50 and 60 examples of the radio bursts. Good said that “if we had 1,000 examples, we would be able to say many more things about what FRBs are like.” The CHIME telescope found, as phrased by Nature.com, “the second known FRB that repeats, meaning that the radio flashes re-appear at the same point in the sky.” The first FRB that repeats was detected in 2012. The majority of the FRBs discovered by the telescope showed signs of “scattering,” Phys.org reported — which led the CHIME team to believe the radio bursts are “powerful astrophysical objects.” “That could mean in some sort of dense clump like a supernova remnant,” Cherry Ng, an astronomer at the University of Toronto, told the news outlet. “Or near the central black hole in a galaxy. But it has to be in some special place to give us all the scattering that we see.” Astronomers’ studying of FRBs can teach those who study more about where the bursts come from, and whether that region in its galaxy is home to turbulent gas. “Until now, there was only one known repeating FRB.,” astronomer Ingrid Stairs, also a member of the CHIME team, said. “Knowing that there is another suggests that there could be more out there. And with more repeaters and more sources available for study, we may be able to understand these cosmic puzzles — where they’re from and what causes them.”

Fascinating!!   🙂

How to Watch the Longest ‘Blood Moon’ Eclipse of the Century

Get ready for a celestial double feature unlike anything seen in decades: Mars is about to make its closest approach to Earth in 15 years—just as the full moon blushes red in the longest “blood moon” eclipse of the century. Both the moon and Mars will dominate the overnight hours on July 27 and into the morning of July 28, traveling across the sky beside each other while appearing to be separated by only five degrees, equal to the width of three middle fingers held at arm’s length. On the 27th, the red planet will swing the closest it has come to Earth since August 2003, allowing sky-watchers around the world to see our neighboring world about as big and bright it can ever get in our skies. And while you shouldn’t expect Mars to look as big as the full moon, as many online hoaxes in past years have suggested, you will also get to see the actual moon painted red as it undergoes a total lunar eclipse. During a total eclipse, sunlight shining through Earth’s dusty atmosphere is bent, or refracted, toward the red part of the spectrum as it is cast onto the moon’s surface. As a result, expect to see the lunar disk go from a dark gray color when the eclipse starts to a reddish-orange color during totality. At 1 a.m. ET (5:00 UT) on July 27, Mars will reach what astronomers call opposition. This is when the sun, Earth, and Mars are aligned in a straight path, so that Mars appears to rise in the east just as the sun sets in the west, making the sunlit side of the planet visible all night long. Mars reaches opposition only once every 26 months, when Earth manages to overtake the planet in its tighter track around the sun. But unlike Earth’s more circular orbit, Mars’s path around the sun is fairly elliptical. That means the distance between the two worlds varies, making some oppositions better than others. Mars will make its closest approach to Earth for this year on July 31, coming just 35.8 million miles (57.6 million kilometers) away. Such a close approach just a few days after opposition means the July 27 alignment will be your best bet to see the red planet shine its biggest and brightest until 2035. The previous best encounter occurred 15 years ago, when Mars was a record-breaking 35 million miles (56 million kilometers) distant. Such an epic encounter won’t happen again until 2287. In addition to offering beautiful views, opposition has traditionally set the stage for robotic invasions of Mars. Because of Mars’s proximity and alignment with our planet, the time around opposition is the best for sending spacecraft, saving travel time and fuel costs. For instance, NASA’s Insight lander launched on May 5 and is headed for a Mars landing this November. Many keen-eyed onlookers may have already noticed the fiery planet growing brighter in our night skies the past few months, making it easy to spot with nothing more than the naked eye. To track down the warrior planet for yourself, go outside after dusk on any clear night and look for the bright beacon rising above the eastern horizon. Mars will glide high over the southern sky throughout the night, setting in the west by dawn. Most of the time, Mars is not much to look at through a telescope, but that changes during opposition, when the planet becomes a disk filled with tantalizing features. Even a small telescope with about a six-inch mirror will be able to tease out surface details like the southern ice cap (where astronomers may have just found an underground lake) and distinct, dark regions that are windswept, rocky fields. However, a colossal dust storm has been raging for the past two months on Mars and has enveloped most of the planet, which means telescope views have been a bit hindered. But you can plainly see the effect of all this dust with the naked eye: Mars currently appears to shine with a more yellowish tinge rather than its usual rusty orange hue. Also on July 27, fortunate sky-watchers in South America, Africa, Europe, Australia, and Asia will get to see at least part of the longest-lasting total lunar eclipse of the 21st century. The entire event will last nearly four hours, with the maximum eclipse lasting for one hour, 42 minutes, and 57 seconds from 19:30 to 21:13 UTC. North Americans will mostly miss out on this lunar eclipse, as the moon will not have risen yet. But the lunar display can be observed in its partial phases rising over South America, western Africa, and Europe and setting over Eastern Asia and Australia. The entire eclipse will be visible from eastern Africa and central Asia.

Bummer we probably won’t be able to see it.  But, it’ll be streamed live online.  For more, click on the text above.

Nearby alien planet may be capable of supporting life

One of the nearest exoplanets to Earth may be a decent abode for life. Ross 128b — which lies just 11 light-years from our planet — is likely a rocky and temperate world, a new study suggests. “Although Ross 128b is not Earth’s twin, and there is still much we don’t know about its potential geologic activity, we were able to strengthen the argument that it’s a temperate planet that could potentially have liquid water on its surface,” lead author Diogo Souto, of the Observatório Nacional in Rio de Janeiro, Brazil, said in a statement. Ross 128b has excited and intrigued astrobiologists since its discovery last year. The planet appears to circle in the “habitable zone” of its host star — that just-right range of distances where liquid water could exist on a world’s surface. (Ross 128b circles a small, dim red dwarf star, so the habitable zone is quite close in; the planet completes one orbit every 9.9 Earth days.) Initial estimates also indicated that Ross 128b has a minimum mass just 1.35 times that of Earth and therefore stands a good chance of being rocky, just like our own planet. The new study will not dampen that enthusiasm. The researchers analyzed Ross 128b’s parent star, known as Ross 128, using the Sloan Digital Sky Survey’s Apache Point Observatory Galactic Evolution Experiment (APOGEE), a spectroscopic instrument installed on a telescope in New Mexico. “The ability of APOGEE to measure near-infrared light, where Ross 128 is brightest, was key for this study,” study co-author Johanna Teske, of the Carnegie Institution for Science in Washington, D.C., said in the same statement. “It allowed us to address some fundamental questions about Ross 128b’s ‘Earth-like-ness.'” The APOGEE data revealed the abundances of certain key elements in Ross 128, including carbon, oxygen, magnesium and iron. Because stars and their orbiting planets coalesce from the same massive cloud of raw materials, this information revealed some key characteristics about Ross 128b as well. For example, the stellar abundances, combined with Ross 128b’s known minimum mass, suggest that the planet’s radius is less than 1.7 times that of Earth. That’s the rough threshold beyond which worlds have a significant gassy envelope — meaning that Ross 128b is probably rocky. In addition, the red dwarf’s observed iron-to-magnesium ratio indicates that Ross 128b’s core is larger than that of Earth, the researchers said. The team also determined that temperatures at or near the “surface” of the star are around 5,400 degrees Fahrenheit (3,000 degrees Celsius). The researchers used this information, along with Ross 128b’s radius and orbital distance, to figure out how much stellar energy the planet receives — and, therefore, how hot it’s likely to be. The result? Ross 128b probably has an “equilibrium temperature” of about 70 degrees Fahrenheit (21 degrees C). This shouldn’t be taken as gospel, however; planets’ temperatures depend greatly on the composition and thickness of their atmospheres, and the nature of Ross 128b’s air is a complete mystery. The new study was published last month in The Astrophysical Journal Letters.

Very cool!!    🙂

Black box set to revolutionize the search for life beyond Earth

In the world’s driest desert, an unassuming black box called “Espresso” is about to begin a very big mission: scouring the universe for planets like ours to find signs of life beyond Earth. Espresso, an instrument known as a spectrograph, has a humble appearance that belies its cutting-edge technology: it is the most precise instrument of its kind ever built, 10 times stronger than its most powerful predecessor. In the Atacama desert, in northern Chile, Espresso will be hooked up to four telescopes so big that scientists simply named them the Very Large Telescope, or VLT. Together, they will search the skies for exoplanets — those outside our own solar system — looking for ones that are similar to Earth. The Atacama is a particularly good place for this kind of exploration. Its skies are completely cloudless most of the year, which is why the highly respected European Southern Observatory, which runs the VLT program, set up shop there in the first place. In fact, many of the world’s major telescopes are located in the area. By 2020, the Atacama is expected to be home to about 70 percent of the world’s astronomy infrastructure. Espresso stands for Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations. It will analyze the light of the stars observed by the VLT, enabling it to determine whether planets orbit around them, and important information about those planets themselves: what their atmosphere is like, whether they have oxygen, nitrogen and carbon dioxide, and whether there is water — all essential for supporting life. “Espresso will be available on all four telescopes at once, which is something that had never been done before. That means the likelihood of finding planets similar to Earth in mass and size, or the conditions for life, are greater,” said Italian astronomer Gaspare Lo Curto.

Very cool!!   🙂

Does dark energy exist?

Newsflash: the universe is expanding . We’ve known that since the pioneering and tireless work of Edwin Hubble about a century ago, and it’s kind of a big deal. But before I talk about dark energy and why that’s an even bigger deal, I need to clarify what we mean by the word “expanding.” The actual observation that you can do in the comfort of your own home (provided you have access to a sufficiently large telescope and a spectrograph) is that galaxies appear to be receding from our own Milky Way. On average, of course: galaxies aren’t simple creatures, and some, like our a-little-too-close-for-comfort neighbor Andromeda, are moving toward us. This recession is seen in the redshifting of light from those galaxies. The fingerprint frequencies of certain elements are shifted down to lower frequencies, exactly like they are for the Doppler effect. But to explain the cosmological observations as a simple Doppler shift requires a few head-scratching conclusions: 1) We are at the center of the universe; 2) Galaxies have preposterous mechanisms that propel them through space; and 3) The universe conspires to make galaxies twice as far away from us move exactly twice as fast. That seems like a bit of a stretch, so astronomers long ago reached a much more simple conclusion, one powered by the newfangled general theory of relativity : the space itself between galaxies is expanding, and galaxies are just along for the ride. Edwin Hubble established the expansion of the universe by cataloging nearby galaxies (after discovering that there is such a thing as “nearby galaxies”). But the story of dark energy doesn’t get told by neighborhood redshifts. The game of cosmology in the latter half of the 20th century was to go deep. Way deep, which is challenging because deep-space objects are a little dim. Thankfully, nature gave scientists a break (for once). A certain sub-sub-subclass of supernova explosions , known as Type 1a, has two useful characteristics. Because Type 1a supernovae tend to happen from roughly the same scenario — a white dwarf accretes gas from an orbiting companion until a critical threshold is reached, a nuclear chain reaction goes haywire and boom — they have roughly the same absolute brightness. By comparing the observed brightness of a Type 1a supernova to the known true brightness (calibrated using handy nearby sources), a little high-school trigonometry reveals a distance. But wait, there’s more! Since Type 1a supernovae contain the same mix of elements, we can easily identify their fingerprint frequencies and measure the redshift, and hence a speed. Distance and speed all in one measurement. How convenient. Type 1a supernovae are relatively rare — only a small handful will light up each galaxy every century. But since there are so many galaxies in the universe, they’re constantly popping off somewhere. And they’re insanely bright, too. For a few weeks, a single explosion can outshine its entire host galaxy. That’s hundreds of billions of stars for those of you keeping track. As the light travels to our telescopes from a distant supernova, the expansion of the universe will stretch it out to longer wavelengths. The further in the past the supernova exploded, the longer the light has traveled to reach us, and the more stretching it has accumulated. So a single supernova redshift measurement gives us the total amount of universal stretch in the intervening billions of years between us and the explosion. By performing multiple measurements at multiple distances, we can build a cosmic growth chart, mapping the expansion of the universe as a function of its age. And that’s where dark energy enters the fray. In the 1990s, after a decade of technology development, the stage was finally set for supernovae to shed some light on the expansion of the universe. Specifically, its deceleration. In a universe full of matter, the expansion should slowly be wearing out as its gravitational pull tugs back. We didn’t know how much matter was in the universe, but a measurement of the cosmic growth chart would help pin it down. Easy, peasy. At first the results were promising: two competing groups both provided initial results of a detectable deceleration rate, but with necessarily large error bars (they were just getting started, after all). But in the coming months, things started to go downhill. As more supernovae data came back from the surveys, the measured deceleration shrank. Then vanished. Then reversed. It appeared that the expansion of the universe was accelerating. Both groups frantically tried to figure out the bugs in their data-analysis pipelines. Surely something was amiss, and each was worried that the other group might steal its thunder by publishing a sound measurement while it was still fiddling with its codes. But the data refused to budge. Nervously, cautiously, the groups reached out to each other: “Do you see what we see?” It was then that the groups began to appreciate what the universe was telling them. Two competing teams, using different telescopes, different datasets and different methodologies, were independently coming to the same conclusion. Our universe wasn’t slowing down, but speeding up . They published their work almost 20 years ago. In the meantime, after several independent lines of evidence all pointed to the same conclusion, they shared in a Nobel Prize for their unexpected discovery. The name for that observed phenomenon — dark energy — sticks with us today, but we still don’t understand it. We don’t know why the expansion of the universe is accelerating, but we do know that it does accelerate. Learn more by listening to the episode “Does Dark Energy Exist? ” on the Ask A Spaceman podcast, available on iTunes and on the web at http://www.askaspaceman.com . Thanks to Mike N., @al_mcclintock, Philip A., Walt A., Cheryl B. and Vick K. for the questions that led to this piece! Ask your own question on Twitter using #AskASpaceman or by following Paul @PaulMattSutter and facebook.com/PaulMattSutter .

Fascinating!!     Astrophysicist Paul Sutter at The Ohio State University is responsible for that outstanding science lesson.       🙂

Scientists may have found evidence of a parallel universe

The idea that we might be living in just one of an infinite number of universes has been fodder for scientific debate and sci-fi movie plots for a long time, but coming up with evidence to support the theory has been hard to come by. Now, researchers have discovered something in space that they can’t quite account for, and one of the possible explanations is that — are you sitting down? — our universe actually bumped into a neighboring, parallel one. When gazing into the heavens, scientists spotted what they refer to as a “cold” area of space. It was observed some time ago, and explaining it proved difficult, but a 2015 study suggested it was merely an area of the universe in which the number of galaxies is dramatically lower than the rest. Unfortunately, subsequent investigations couldn’t support that finding, and a new study by Durham University suggests the slim possibility that it’s actually evidence of parallel universes is still on the table. The multiverse theory hinges on the idea that all possible outcomes of any given scenario are all playing out at the same time in a layered reality of which we are only experiencing one layer. It’s a wild idea that has a foundation in quantum mechanics, but it’s also entirely unproven. As the study states, the researchers believe the mysterious cold spot, while still totally unexplained, could actually be “the remnant of a collision between our universe and another ‘bubble’ universe during an early inflationary phase.” In short, if the idea is correct, our early universe collided with another young universe early on, causing something of a “bruise” which we are able to observe today.

Fascinating!!

The best times to see November’s big supermoon

This Monday stargazers will get to experience a rare, extra bright supermoon. Want to make sure to spy it? According to NASA, the best time to see it is early Monday morning before sunrise, as the moon is closest to Earth at 6:22 am, EST. But Sunday night and Monday night are also really good times to see Earth’s natural satellite. “I’ve been telling people to go out at night on either Sunday or Monday night to see the supermoon,” Noah Petro, deputy project scientist for NASA’s Lunar Reconnaissance Orbiter mission, said in a statement. “The difference in distance from one night to the next will be very subtle, so if it’s cloudy on Sunday, go out on Monday. Any time after sunset should be fine.” The last time the full moon was this close to Earth was 1948, NASA says. The moon only appears full from Earth when our planet is between the sun and the moon. But since the moon’s orbit has an elliptical shape, sometimes it is closer to Earth than other times. Astronomers call the closest-to-the-Earth moment the perigee. What makes November 14 special is that the moon “becomes full within about two hours of perigee—arguably making it an extra-super moon,” NASA explained. In short: a so-called supermoon occurs when a full moon happens as the moon is also closest to Earth. NASA says that Earth can be bathed in 30 percent more moonlight during a supermoon. This year actually has three supermoons. Besides November’s, there was one on October 16 and will be another on December 14, although neither are as close as this month’s. The November 14 supermoon is not only the closest full moon of the century so far, it won’t be matched until 2034. So if you miss this one, mark your calendar for November 25 of that year.

Fun!   🙂