Astronomy

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!   🙂

‘Blue moon’ rises Saturday — but it won’t be blue: A full moon history

This weekend, a full moon will rise in the night sky, a so-called “Blue Moon.” Typically, a Blue Moon is defined as the second full moon that occurs during a calendar month, but the full moon this Saturday (May 21) will be the only full moon of May 2016. So, how can it be called a Blue Moon? The explanation points back to a somewhat obscure rule. In fact, the current rule of two full moons in one month has superseded the rule that would allow this month’s full moon to be called “blue.” If you’re confused, don’t worry.

You’re not alone.. I’m right there with ya’. Just click on the text above to read “the rest of the story.” Then, go out this evening to see this “Blue Moon.” 🙂

Stargazers have a chance to see bright green comet next week

When scientists started tracking Comet 252P/LINEAR, they figured it would pass Earth without a trace. But then something strange happened. The icy object started brightening abruptly a few weeks ago and has become 100 times brighter than expected, according to the astronomy magazine Sky and Telescope. As a result, observers from the Southern Hemisphere have caught a glimpse of the comet that is believed to be about 750 feet in size. They have been able to see it with their naked eye and the comet appeared greenish in color. Now, it’s the Northern Hemisphere’s turn. Starting Tuesday, stargazers with their binoculars could spot Comet 252P/Linear in the sky – though the view isn’t expected to be as good due the glow of the Moon and natural light pollution. You’ll have to be out at least 90 minutes before sunrise and in a location as free of light pollution as possible. Once you have managed that, locate the constellations Sagittarius and Scorpius low in the southern part of the sky. The comet is expected to move between those two constellations. Another option is locating Saturn and Mars. They and the bright star Antares will be the first things you notice, forming a distinctive triangle a little smaller than your clenched fist held at arm’s length. The comet will be the dot climbing to the left of this trio and will be roughly in line with Mars and Saturn on the morning of March 29th and along a line connecting Saturn and Antares on March 31st. “Don’t expect Comet LINEAR to be obvious with a long tail,” Sky & Telescope Senior Editor Kelly Beatty said in a statement. “Its light isn’t concentrated in a single point but instead is spread out in a soft round glow, larger than the Moon but many thousands of times dimmer.” Astronomers aren’t sure how long it will remain visible, especially since it passed closest to Earth, just 3.3 million miles away, on March 21st. Now, it’s moving away from both Earth and the Sun.

Very cool!!  To read the rest of this article, click on the text above.     🙂

Five ‘bright’ planets set to align in dawn sky

Stargazers are in for a treat starting Wednesday when all five visible planets – Mercury, Venus, Mars, Jupiter and Saturn, will be visible in the morning sky. Earth Sky reports that the planets will appear together before dawn from about Jan. 20 to Feb. 20. The last time the stars aligned in this fashion was from Dec. 15, 2004 to Jan. 15, 2005. “In their outward order from the sun, the five bright planets are Mercury, Venus, Mars, Jupiter and Saturn,” explained Earth Sky. “These planets are easily seen in our sky because their disks reflect sunlight, and these relatively nearby worlds tend to shine with a steadier light than the distant, twinkling stars.” In September 2015 stargazers were treated to a rare supermoon eclipse – the first time that a supermoon had coincided with a lunar eclipse since 1982. Although past sky shows have sent the astrological community into overdrive with doomsday predictions, Bustle.com is offering up five fun ways to celebrate the event.

Very cool!!  Get up early and check this out, if ya can!   🙂