Meet Kepler-22b, an exoplanet with an Earth-like radius in the habitable zone of its host star. Unfortunately its mass remains unknown. Image Credit: NASA
Astronomers constantly probe the skies for the unexpected. They search for unforeseen bumps in their data — signaling an unknown planet orbiting a star, a new class of astronomical objects or even a new set of physical laws that will rewrite the old ones. They are willing to embrace new ideas that may replace the wisdom of years past.
But there’s one exception to the rule: the search for Earth 2.0. Here we don’t want to find the unexpected, but the expected. We want to find a planet so similar to our own, we can almost call it home.
While, we can’t exactly image these planets with great enough detail to see if one’s a water world with luscious green plants and civilizations, we can use indirect methods to find an “Earth-like” planet — a planet with a similar mass and radius to the Earth.
There’s only one problem: the current techniques to measure an exoplanet’s mass are limited. To date astronomers measure radial velocity — tiny wobbles in a star’s orbit as it’s tugged by the gravitational pull of its exoplanet — to derive the planet-to-star mass ratio.
But given that most exoplanets are detected via their transit signal — dips in light as a planet passes in front of its host star — wouldn’t it be great if we could measure its mass based on this method alone? Well, astronomers at MIT have found a way.
Graduate student Julien de Wit and MacArthur Fellow Sara Seager have developed a new technique for determining mass by using an exoplanet’s transit signal alone. When a planet transits, the star’s light passes through a thin layer of the planet’s atmosphere, which absorbs certain wavelengths of the star’s light. Once the starlight reaches Earth it will be imprinted with the chemical fingerprints of the atmosphere’s composition.
The so-called transmission spectrum allows astronomers to study the atmospheres of these alien worlds.
But here’s the key: a more massive planet can hold on to a thicker atmosphere. So in theory, a planet’s mass could be measured based on the atmosphere, or the transmission spectrum alone.
Of course there isn’t a one to one correlation or we would have figured this out long ago. The atmosphere’s extent also depends on its temperature and the weight of its molecules. Hydrogen is so light it slips away from an atmosphere more easily than, say, oxygen.
So de Wit worked from a standard equation describing scale height — the vertical distance over which the pressure of an atmosphere decreases. The extent to which pressure drops off depends on the planet’s temperature, the planet’s gravitational force (a.k.a. mass) and the atmosphere’s density.
According to basic algebra: knowing any three of these parameters will let us solve for the fourth. Therefore the planet’s gravitational force, or mass, can be derived from its atmospheric temperature, pressure profile and density — parameters that may be obtained in a transmission spectrum alone.
With the theoretical work behind them, de Wit and Seager used the hot Jupiter HD 189733b, with an already well-established mass, as a case study. Their calculations revealed the same mass measurement (1.15 times the mass of Jupiter) as that obtained by radial velocity measurements.
This new technique will be able to characterize the mass of exoplanets based on their transit data alone. While hot Jupiters remain the main target for the new technique, de Wit and Seager aim to describe Earth-like planets in the near future. With the launch of the James Webb Space Telescope scheduled for 2018, astronomers should be able to obtain the mass of much smaller worlds.
The paper has been published in Science Magazine and is now available for download in a much longer form here.
Growing up, my sister played video games and I read books. Now that she has a one-year-old daughter we constantly argue over how her little girl should spend her time. Should she read books in order to increase her vocabulary and stretch her imagination? Or should she play video games in order to strengthen her hand-eye coordination and train her mind to find patterns?
I like to believe that I did so well in school because of my initial unadorned love for books. But I might be about to lose that argument as gamers prove their value in science and more specifically astronomy.
Take a quick look through Zooniverse and you’ll be amazed by the number of Citizen Science projects. You can explore the surface of the moon in Moon Zoo, determine how galaxies form in Galaxy Zoo and search for Earth-like planets in Planet Hunters.
In 2011 two citizen scientists made big news when they discovered two exoplanet candidates — demonstrating that human pattern recognition can easily compliment the powerful computer algorithms created by the Kepler team.
But now we’re introducing yet another Citizen Science project: Disk Detective.
Planets form and grow within dusty circling planes of gas that surround young stars. However, there are many outstanding questions and details within this process that still elude us. The best way to better understand how planets form is to directly image nearby planetary nurseries. But first we have to find them.
“Through Disk Detective, volunteers will help the astronomical community discover new planetary nurseries that will become future targets for NASA’s Hubble Space Telescope and its successor, the James Webb Space Telescope,” said the chief scientist for NASA Goddard’s Sciences and Exploration Directorate, James Garvin, in a press release.
NASA’s Wide-field Infrared Survey Explorer (WISE) scanned the entire sky at infrared wavelengths for a year. It took detailed measurements of more than 745 million objects.
Astronomers have used complex computer algorithms to search this vast amount of data for objects that glow bright in the infrared. But now they’re calling on your help. Not only do planetary nurseries glow in the infrared but so do galaxies, interstellar dust clouds and asteroids.
While there’s likely to be thousands of planetary nurseries glowing bright in the data, we have to separate them from everything else. And the only way to do this is to inspect every single image by eye — a monumental challenge for any astronomer — hence the invention of Disk Detective.
Brief animations allow the user to help classify the object based on relatively simple criteria, such as whether or not the object is round or if there are multiple objects.
“Disk Detective’s simple and engaging interface allows volunteers from all over the world to participate in cutting-edge astronomy research that wouldn’t even be possible without their efforts,” said Laura Whyte, director of Citizen Science at the Adler Planetarium in Chicago, Ill.
The project is hoping to find two types of developing planetary environments, distinguished by their age. The first, known as a young stellar object disk is, well, young. It’s less than 5 million years old and contains large quantities of gas. The second, known as a debris disk, is older than 5 million years. It contains no gas but instead belts of rocky or icy debris similar to our very own asteroid and Kupier belts.
So what are you waiting for? Head to Disk Detective and help astronomers understand how complex worlds form in dusty disks of gas. The book will be there when you get back.
Orion steps above towering spruce on a January evening. Credit: Bob King
Bitter cold lies ahead for many skywatchers in the U.S. and Canada in the coming week as the polar vortex swoops down from Santa’s village for round two this season. Will that stop you from going out to enjoy the winter wonders of Jupiter, the M82 supernova and Orion? It needn’t if you take the proper precautions.
In all honesty, you’ll probably still get cold if you attempt to observe on windy, subzero nights, but if you follow these helpful hints, you won’t get as cold. That said, there are two key ingredients to a successful and happy night under the winter sky: dressing well and planning in advance what you want to see.
I know it looks like an alien abduction with only the clothes left behind, but consider this an illustration of good nighttime winterwear. Credit: Bob King
Dressing well means having to accept the fact that even though you still feel warm walking out the door, 10 minutes later you won’t be. Always layer to the hilt. Insulated pack boots like those made by Sorrel or LaCrosse will keep your feet toasty for at least an hour of standing in place at the telescope.
I still wear blue jeans during winter, but when out getting a winter star tan, I pull on a pair of insulated snow pants. To keep heat from escaping the rest of the body, a flannel shirt, thick sweater and some kind of down or insulated coat will provide protection right up to your neck. Some folks like the all-in-one approach and don a snowmobile suit. Add a scarf, a bomber cap with furry ear flaps for the head region and lined mittens or gloves for your digits, and you’re almost ready to do battle. Assuming you still have energy left after building a fortress around your person.
Tuck chemical hand warmer packets inside your gloves or boots. Credit: Bob King
About gloves. I use lined deerskin gloves with chemical hand-warmers nestled in each palm. It’s so nice to have something warm to push your fingers into when they get chilled. Others prefer the wiser dual-glove approach – wearing a pair of thin gloves inside mittens that Velcro open across the palm. That way you use your fingers to adjust focus or check a chart and then safely tuck your hands back into the mittens.
On super-cold nights I’ll set the telescope up right outside the house so I can bail when necessary, but on exceptional nights when it might be well below zero but not windy, I’ll make the drive to the country for darker skies and set up on the proverbial road in the middle of nowhere.
I limit my observing to two hours maximum. Not because I have any control over time; that’s as much as this body can take when it’s -20 F. One little trick I’ve employed over the years to survive astronomical cold is to keep moving. I check charts constantly, set eyepieces down in the trunk of the car, then return to pick up a different eyepiece, take a short walk and even run in place. Hey, only the wolves are watching, so who cares? All this to keep the body moving to generate heat.
On very cold nights it’s a good idea to make a concise observing plan to efficiently use your time at the telescope. I grab a few charts and often take brief notes outside using a red flashlight. Credit: Bob King
If I do freeze, the car provides some solace. A typical drive home will find me steering with my inner arms, my crabbed hands straining to absorb every molecules of hot air blasting from the vents
The second key ingredient to a successful, soulful, subzero night is planning. If you prepare a short list either on paper or mentally of winter sky gems before you walk out the door, you’ll spend your stellar minutes more efficiently and return indoors a happy camper.
I keep it simple. If there’s a bright planet out, that’s always on my list. With Jupiter shining so enticingly these nights, how can you not go out to see what the weather’s doing on the solar system’s biggest planet? Relish the thought that the cloud tops you’re seeing are cold enough at -230 F (-145 C) to snow ammonia flakes. Makes 20 below almost seem like shirtsleeve weather.
A well-dressed stargazer relishes a night under the winter stars. Credit: Bob King
Add in a few variable stars, a supernova, maybe a comet and two or three deep sky objects and I feel a sense of connection and accomplishment by the time I return inside to what now feels like a Hawaiian vacation in my living room. Total time elapsed: maybe an hour. Too much? 15 minutes for a pretty double star and a current planet will do. Astronomy photos, articles and book are great, but we all need the real thing from time to time; there’s no substitute for a direct connection to the cosmic wilderness.
One crucial tip on doing astronomy in winter. Make sure your telescope is COLD. A spare meat locker for storage would be ideal. Barring that, place the scope outside and let it cool down before you begin your observing session. If it comes directly from the house, 45 minutes to an hour should be enough, depending on the temperature and aperture size. If you store it in a garage or shed, 20 minutes should do the trick.
A brilliant moonlit night in January with the Big Dipper rising in the northeastern sky. Credit: Bob King
Ready to zip up? Go for it! I ran into a woman a couple weeks back who told me she loved winter because the cold made her feel alive. Man, she hit it right on the head. I’ll leave you with a quote from one of my favorite old-time authors, Joseph Elgie, an English amateur astronomer who wrote about the pleasures of the sky no matter the season in a book titled The Night Skies of a Year. This entry is from February about the year 1907:
“Shortly after nine o’clock Procyon could be seen through the openings in the flying clouds, not far from the meridian. The sky resembled a vast snow-field in swift motion – a snow field showing fleeting patches of blue, which were studded with sparklets of silver, and Procyon was one of those sparklets. In the sou’west too, I could discern a coppery gleam on the pale blue background of the sky. It was Betelgeuse. What pictures of tender loveliness were these!”
In the early pre-dawn hours on December 19, 2013, with a rumble and a roar, a Soyuz rocket blazed through the clouds above the jungle-lined coast of French Guiana, ferrying ESA’s long-awaited Gaia spacecraft into orbit and beginning its mission to map the stars of the Milky Way. The fascinating time-lapse video above from ESA shows the Gaia spacecraft inside the clean room unfurling like a flower during its sunshield deployment test, the transfer of the Soyuz from the assembly building to the pad, and then its ultimate fiery liftoff.
That’s a lot going on in two minutes! But once nestled safely in its L2 orbit 1.5 million kilometers out, Gaia will have over five years to complete its work… read more here.
Credit: ESA–S. Corvaja, M. Pedoussaut, 2013. Source: ESA
What’s the oldest thing you’ve ever held in your hand? A piece of petrified wood? A fossilized trilobite? A chunk of glacier-carved granite? Those are some pretty old things, sure, but there are even older objects to be found across the world… that came from out of this world. And thanks to “Meteorite Men” co-host, author, and educator Geoff Notkin and his company Aerolite Meteorites, you can own a truly ancient piece of the Solar System that can date back over 4.5 billion years.
Founded in 2005, Aerolite (which is an archaic term for meteorite) offers many different varieties of meteorites for sale, from gorgeous specimens worthy of a world-class museum to smaller fragments that you could proudly — and economically — display on your desk. Recently I had the opportunity to talk in depth with Geoff about Aerolite and his life’s work as a meteorite collector and dealer. Here are some of the fascinating things he had to say…
So Geoff, what initially got you interested in meteorites and finding them for yourself?
“It’s been a lifelong passion for me, but I’m lucky in that I can really put my finger on a specific event when I was a kid and that was my mother taking me to the Geological Museum in London when I was six or seven… I was already a rock hound, I loved collecting fossils, and my dad was a very keen amateur astronomer. And so I had this love of astronomy and this fascination with other worlds for as long as I can remember. I’m a very tactile person; I’m very hands-on. I like to know how things work… I want to know all the bits and pieces. I was frustrated a bit, because I wanted to know more about astronomy. I could see all these planets and places through the ‘scope, but I couldn’t touch them. But I could touch rocks and fossils.
“So I’m six or seven years old, and I’m on the second floor of the Museum in the Hall of Rocks and Minerals. And at the back was this small display area that’s very dark. And you walked through an arch, it’s almost like walking into a cave. And it was very low light back there, and that was the meteorite collection.
“There were a couple of large meteorites on stands, and in those days — it was the late 60s — security wasn’t the issue that it is today. So you could touch the big specimens, and so I put my hands on these giant meteorites and I was absolutely enthralled. And I had this sort of epiphany: meteorites were the locus between my two interests, astronomy and rock-hounding. Because they’re rocks… they’re rock samples from outer space. I promised myself as a kid that one day I would have an actual meteorite.
“By finding or owning meteorites, you are forging a solid and tangible connection with astronomy.”
“Of course at the time there was no meteorite business, no meteorite magazines, there was no network of collectors like there is today. Back in the late 60s when I gave myself this challenge it was like saying I was going to start my own space program! But not only did it come true, it’s become my career.”
What makes Aerolite such a great place to buy meteorites?
“I think the caring for the subject matter really shows on the website. We have the best photography in the entire meteorite industry. I think we have the largest selection… we certainly spend a great deal of time discussing the history and importance of pieces… every single meteorite on our website has a detailed description and in most cases multiple photographs. My view is if you’re going to do something, you should really do it to the best of your ability. We don’t cut any corners, we don’t sell anything unless we’re one hundred percent sure of what it is and where it came from.
“I want buyers and visitors to look at the website and share my sense of wonder about meteorites. I think meteorites are the most wonderful things in existence, they’re actual visitors from outer space — they’re inanimate aliens that have landed on our planet.”
“We do this because we want to share our passion. We stand by every piece that we sell.”
How can people be sure they are getting actual meteorites (and not just funny-looking rocks?)
“This is something that’s more important to pay attention to now than ever. Are there fakes, are there shady people? Yes and yes. If you go on eBay at any given time you will find numerous pieces that are being offered for sale that are either not meteorites at all or are one thing being passed off as another thing. Sometimes this is malicious, sometimes people just don’t know any better. So the best way to buy a meteorite and know that it’s real is to buy from a respected dealer who has a solid history in the field.
“I’m by no means the only person who does this. There are a number of very well-established dealers around the world, and a good place to start is the International Meteorite Collectors Association(of which Geoff is a member) which is an international group with hundreds of members — collectors and dealers… it’s sort of a watchdog group that tries to maintain high standards of integrity in the field.
“My company has a very strict policy of never offering anything that’s questionable.”
“I see fakes all the time,” Geoff added. “On eBay, on websites, in newspaper ads… you do have to be careful. My company has a very strict policy of never offering anything that’s questionable. And we do get offered questionable things. There are some countries that have strict policies about exporting meteorites — Australia and Canada being two of them — and we work very closely with academia in both countries, and we have legally exported meteorites from those countries. Not only do we abide by international regulations, we actively support them.”
So you not only offer meteorites for sale to the general public, but you also donate to schools and museums.
“We work very closely with most of the world’s major meteorite institutions. I have provided specimens to the American Museum of Natural History in New York, the British Museum of Natural History in London, the Vienna Museum of Natural History, the Center for Meteorite Studies… we work with almost everyone. When we find something that is new or different or exciting, we always donate a piece or pieces to our colleagues in academia. It’s just the right thing, it’s the right thing to do if you discover something important to make it available to science.
“Most universities and museums don’t have acquisitions budgets and can’t afford to buy things that they might like to have. In return they classify the meteorites that we found, and they go into the permanent literature and become more valuable as a result. A meteorite with a history and a name and classification is worth more than a random meteorite that somebody just found in a desert. So everybody benefits, it’s a really good match.”
In other words, you really are making a contribution to science as opposed to just “looting.”
“Exactly. And I have, a very few times, gotten emails from disgruntled viewers who didn’t understand what we were doing, saying ‘what makes you think it’s okay to come to Australia and take our meteorites,’ for example. So I wrote a very courteous email back saying that we were in Australia with the express permission and cooperation of the Australian park services and one of the senior park rangers was there with us. And not only did we follow the proper procedure in having those specimens exported from Australia, I donated rare meteorites to collections just as a ‘thank you’ for working with us. It wasn’t a trade, it was a thank you. So everywhere we go, whatever we do, we try and leave a good impression.”
Geoff added, “I do this out of love… this isn’t the best way to make a living! Being a meteorite hunter is probably not the best capital return on your time but it’s a very exciting and rewarding life in every other way.”
And thus, by buying meteorites from Aerolite, customers aren’t just helping pay for your expeditions and your work but also supporting research and education too.
“People who purchase from us are really participating in the growth of this science. Also, something very near and dear to my heart is science education for kids. You know that I am the host of an educational series called STEM Journals, which is a very — I think — amusing, entertaining, funny, fast-paced look at science, technology, engineering, and math topics. But you can’t make a living doing television shows like that. This is a labor of love… we do it because we think it’s important. If I didn’t have a commercial meteorite company to help underwrite the costs of educational programming and educational books, we just couldn’t do it. It’s as simple as that.
“So we always try to give back. That’s why I speak at schools and universities and give away meteorites to deserving kids at gem shows… because it was done to me when I was seven years old. The look of wonder you see on a kid’s face when you connect with them and they start to grasp the wonder of science… that’s something they’ll never forget.”
That’s great. And it sounds like you haven’t forgotten it yet either!
“I must say after all these years, I’ve been doing this close to full time for nearly twenty years and you never lose the amazement and the wonder of when a meteorite’s found or uncovered. I never go ‘oh, jeez, it’s just another billion-year-old space rock that fell to Earth!’ So it is a privilege to be in a work field where almost daily something wondrous happens.”
As we here at Universe Today know, when it concerns space that’s a common occurrence!
“Exactly!”
One last thing Geoff… do you think we’ll ever run out of meteorites?
“The meteorite collecting field has grown tremendously in the past ten years, and Meteorite Men is part of that. There is a finite supply of meteorites. Of course there are more landing all the time, but not enough to replenish the demand. Periodically there is a new very large discovery made, such as the Gebil Kamil iron in Egypt a couple of years ago. But what is happening is a significant increase in price and a decrease in selection, so some of the real staples we used to see… you can’t get them anymore.
“Still, people who want a meteorite collection, now is a great time for them to be buying because there are more meteorites available than in the past — but it’s not going to stay that way for very long. It’s like any other collectible that has a finite supply.”
Makes sense… I’ll take that as ‘inside advice’ to place an order soon!
______________
My thanks to Geoff for the chance to talk with him a little bit about his fascinating past, his passion, and his company. And as an added bonus to Universe Today readers, Geoff is extending a special 15% off on orders from Aerolite Meteorites — simply mention the code UNIVERSETODAY when you place an order!* (Trust me — once you browse through the site you’ll find something you want.) Also, if you’re in the Tucson area, Geoff Notkin and Aerolite Meteorites will have a table at the Tucson Gem and Mineral Show starting Jan. 31.
One of several meteorite-hunting books by Geoff, featuring an introduction by Neil Gaiman.
Be sure to check out Geoff’s television show STEM Journals on COX7 — the full first two seasons can be found online here and here, and shooting for the third season will be underway soon.
Want to know how to find “inanimate aliens” for yourself? You can find Geoff’s books on meteorite hunting here, as well as some of the right equipment for the job.
Zodiacal light over Charleston, RI (Scott MacNeill, Frosty Drew Observatory)
The result of sunlight reflected off fine particles of dust aligned along the plane of the Solar System, zodiacal light appears as a diffuse, hazy band of light stretching upwards from the horizon after sunset or before sunrise. Most people have never seen zodiacal light because it’s very dim, and thus an extremely dark sky is required. But thanks to recent dark sky regulations that were passed in the coastal Rhode Island town of Charlestown, this elusive astronomical phenomenon has become visible — to the particular delight of one local observatory.
Frosty Drew Observatory is a small, privately-run observatory featuring a Meade Schmidt Cassegrain LX200 16″ telescope mounted on an alt-azimuth pier inside a dome that stands among the sports fields, parking areas, and nature trails of Ninigret Park and Wildlife Refuge in southern Rhode Island. Being a good distance from urban centers and developed areas, the skies there are some of the darkest in the state. But situated along the eastern seaboard of the United States, even Charlestown’s coast lies beneath a perpetual haze of light pollution.
A new town ordinance, passed in 2012, helped to darken the skies a notch. And while watching comet ISON one evening, astronomer Scott MacNeill became aware of the results.
The following is an excerpt from a Jan. 7 article by Cynthia Drummond of The Westerly Sun, reprinted with permission:
Scott MacNeill was in Ninigret Park, his telescope trained on the comet “Ison,” when he saw something he had never seen before: a celestial phenomenon called “zodiacal light.” After several decades of being obscured by light pollution, the feature was visible again, thanks to the town’s “dark sky” ordinance.
At first, MacNeill, an astronomer and the assistant director of the Frosty Drew observatory, didn’t believe what he was seeing. The cone of light, which he initially thought was light pollution, turned out to be a faint, white glow that astronomers at the observatory hadn’t glimpsed in recent memory.
A line of visitors is cast in silhouette against the evening sky as they wait to go into the Frosty Drew Observatory. (Susannah Snowden / The Westerly Sun)
“To see it in New England, period, is amazing, Zodiacal light is a common marker for the quality of a dark sky location.”
– Scott MacNeill, Astronomer, Frosty Drew Observatory
“I was sitting back for a minute, just looking at the sky, and I said ‘wait a minute. This is the southeast, and to the southeast is the ocean. What is coming up in the southeast?’ And then I noticed the cone. And I’m like ‘no way. That can’t be zodiacal light.’ I’ve heard so many stories about the days of old at Frosty Drew when you used to see zodiacal light here,” he said.
MacNeill credits Charlestown’s dark sky ordinance with reducing light pollution to the point where zodiacal light can be seen again. The ordinance, adopted in October 2012, regulates commercial outdoor lighting in order to improve the town’s dark sky for star-gazers, and to protect residents, wildlife and light-sensitive plants from the effects of light pollution.
One of the provisions of the ordinance requires that new lighting fixtures be designed to focus downward so light does not radiate up into the sky. Lighting installed before the ordinance was passed is exempt from the new regulations.
Building and Zoning Official Joe Warner explained that after the ordinance passed, two major sources of light pollution near the observatory were modified so they would be less polluting.
“At Ninigret Wildlife Refuge, some of the pole lights were changed to dark sky compliant lighting. The Charlestown Ambulance barn also replaced their lights with dark sky compliant lights,” he said.
Charlestown has been recognized as one of the only dark spots on the New England coast — a rare treat for people who enjoy looking at the night sky.
It’s fantastic to see results like this both occurring and being publicized, as dark skies have become quite rare in many populated areas of the world. People who live in or near major metropolitan areas — even in the surrounding sprawling suburbs — often never truly get a dark sky, not such that the dimmer stars, the Milky Way, meteor showers — and yes, the zodiacal light — can be readily seen on an otherwise clear night. The view of a star-filled night sky that has been a part of the human existence for millennia has steadily been doused by the murky glow of artificial lighting. Luckily groups like the International Dark Sky Association are actively trying to change that, but change isn’t always welcome — or quick.
At least, in one Rhode Island town anyway, a small victory has been won for the night.
(HT to Brown University’s Ladd Observatory in Providence for the heads-up on this story.)
We are awash in the unseen, the unknown and the unexplained. Our Universe is enshrouded in mystery. Even what we do know — the complex physical laws that describe the planets, stars and galaxies — can seem just beyond any normal human being’s grasp. We can’t all be Einsteins, after all.
But excluding string theory, dark energy and quantum field theory most of science is remarkably within our grasp. And in less than a minute, a concept as culturally conflicted and misunderstood as global warming, can be explained. See above.
The motivation behind this video is simple. Research shows that virtually no Americans — roughly 0 percent — can explain the physical mechanisms of global warming at even a basic level. So Berkeley Professor Michael Ranney and colleagues created a total of five videos (with the longest clocking in at 656 words in under five minutes) with the hope of elucidating the basics of global warming.
Their initial study, completed in 2011, surveyed 270 people in San Diego parks in order to assess how well the average American understands global warming. San Diego was chosen because it draws tourists from across the United States, and would thus create a better rounded sample.
“The main concept we were hoping people would tell us, which is at the heart of understanding global warming, is that there is an asymmetry between stuff that’s coming in to our planet and stuff that’s heading out,” Ranney told Universe Today.
This asymmetry explains why sunlight (in the form of visible light) may enter the atmosphere unhindered but is later impeded by greenhouse gases (because it is no longer in the form of visible light — it has been absorbed by the Earth and emitted in the form of infrared light). But not a single person could explain global warming at this basic level.
“We were shocked at how few people knew this” Ranney said. “I thought it was a moral imperative to get the word out as fast as possible.”
So Ranney and his colleagues set out with their work in front of them, creating the videos in order to increase the average American’s understanding of global warming. Their goal is that any one of the five videos will change the lives of seven billion viewers.
“We hope that a video of 400 words or even 35 words will allow people to have a moment in time to which they fix that they knew what the mechanism of climate change was,” Ranney told Universe Today. For that single moment “their knowledge was obvious, valid, understandable and available.”
In order to drive this point home, Ranney used an analogy that began like this: “So a climate change acceptor walks into a bar.” But all jokes aside, if one who accepts anthropogenic global warming tries to convince the man sitting next to him that global warming is real, but cannot explain the physical mechanism behind global warming, then he’s in trouble. He’s likely not only lost his bar mate but encouraged a life-time of global warming denial.
We cannot expect to increase the public’s awareness and acceptance of climate change without a huge increase in scientific literacy. Even if every viewer can’t recall the exact mechanistic details of global warming they can at least say to the man sitting next to them at the bar: “Look, I can’t regurgitate it now but I did understand it then.”
This graph from NOAA shows the annual trend in average global air temperature in degrees Celsius, through December 2012. For each year, the range of uncertainty is indicated by the gray vertical bars. The blue line tracks the changes in the trend over time. Click here or on the image to enlarge. (Image courtesy NOAA’s National Climatic Data Center.)
A second study provided college students with an explanation akin to the one found in the five-minute video. After reading it, the students not only understood global warming better but they were also more likely to accept global warming as a reality — suggesting these videos have the power to change people’s minds.
“Eventually people come to appreciate salient evidence,” Ranney told Universe Today. “Let’s say you think you’re in a fantastic monogamous relationship. If you come home and find your partner with someone else, it only takes that one moment in time to change your belief.”
Helping people to understand the basic physics behind global warming is a vital tool in convincing them that global warming is as real as it gets. Once someone clicks on the video, the next 52 seconds alone might leave a pretty big impact.
Ranney emphasized help from graduate student Lee Nevo Lamprey, undergraduate student Kimberly Le and other collaborators (including Dav Clark, Daniel Reinholz, Lloyd Goldwasser, Sarah Cohen and Rachel Ranney).
Before there was life as we know it, there were molecules. And after many seemingly unlikely steps these molecules underwent a magnificent transition: they became complex systems with the capability to reproduce, pass along information and drive chemical reactions. But the host of steps leading up to this transition has remained one of science’s beloved mysteries.
New research suggests that the building blocks of life — prebiotic molecules — may form in the atmospheres of planets, where the dust provides a safe platform to form on and various reactions with the surrounding plasma provide enough energy necessary to create life.
“If the formation of life is like a jigsaw puzzle — a very big and complicated jigsaw puzzle — I like to imagine prebiotic molecules as some of the individual puzzle pieces,” said St. Andrews professor Dr. Craig Stark. “Putting the pieces together you form more complicated biological structures making a clearer, more recognizable picture. And when all the pieces are in place the resulting picture is life.”
We currently think prebiotic molecules form on the tiny ice grains in interstellar space. While this may seem to contradict the readily accepted belief that life in space is impossible, the surface of the grain actually provides a nice hospitable environment for life to form as it protects molecules from harmful space radiation.
“Molecules are formed on the dust surface from the adsorption of atoms and molecules from the surrounding gas,” Stark told Universe Today. “If the appropriate ingredients to make a particular molecular compound are available, and the conditions are right, you’re in business.”
By “conditions,” Stark is hinting at the second ingredient necessary: energy. The simple molecules that populate the galaxy are relatively stable; without an incredible amount of energy they won’t form new bonds. It has been thought that life could form in lightning strikes and volcanic eruptions for this very reason.
So Stark and his colleagues turned their eyes to the atmospheres of exoplanets, where dust is immersed in a plasma full of positive ions and negative electrons. Here the electrostatic interactions of dust particles with plasma may provide the high energy necessary to form prebiotic compounds.
In a plasma the dust grain will soak up the free electrons quickly, becoming negatively charged. This is because electrons are lighter, and therefore quicker, than positive ions. Once the dust grain is negatively charged it will attract a flux of positive ions, which will accelerate toward the dust particle and collide with more energy than they would in a neutral environment.
In order to test this, the authors studied an example atmosphere, which allowed them to examine the various processes that may turn the ionized gas into a plasma as well as determine if the plasma would lead to energetic enough reactions.
“As a proof of principle we looked at the sequence of chemical reactions that lead to the formation of the simplest amino acid glycine,” Stark said. Amino acids are great examples of prebiotic molecules because they are required for the formation of proteins, peptides and enzymes.
Their models showed that “the plasma ions can indeed be accelerated to sufficient energies that exceed the activation energies for the formation of formaldehyde, ammonia, hydrogen cyanide and ultimately the amino acid glycine,” Stark told Universe Today. “This may not have been possible if the plasma was absent.”
The authors demonstrated that with modest plasma temperatures, there is enough energy to form the prebiotic molecule glycine. Higher temperatures may also enable more complex reactions and therefore more intricate prebiotic molecules.
Stark and his colleagues demonstrated a viable pathway to the formation of a prebiotic molecule, and therefore life, in seemingly common conditions. While the origin of life may remain one of science’s beloved mysteries, we continue to gain a better understanding, one puzzle piece at a time.
The paper has been accepted for publication in the journal Astrobiology and is available for download here.
Saturn makes a beautifully striped ornament in this natural-color image, showing its north polar hexagon and central vortex (Credit: NASA/JPL-Caltech/Space Science Institute)
Cassini couldn’t make it to the mall this year to do any Christmas shopping but that’s ok: we’re all getting something even better in our stockings than anything store-bought! To celebrate the holiday season the Cassini team has shared some truly incredible images of Saturn and some of its many moons for the world to “ooh” and “ahh” over. So stoke the fire, pour yourself a glass of egg nog, sit back and marvel at some sights from a wintry wonderland 900 million miles away…
Thanks, Cassini… these are just what I’ve always wanted! (How’d you know?)
Saturn’s southern hemisphere is growing more and more blue as winter approaches there — a coloration similar to what was once seen in the north when Cassini first arrived in 2004:
Saturn’s southern hemisphere images from a million miles away (Credit: NASA/JPL-Caltech/Space Science Institute)
(The small dark spot near the center right of the image above is the shadow of the shepherd moon Prometheus.)
Titan and Rhea, Saturn’s two largest moons, pose for Cassini:
Rhea (front) and Titan, images by Cassini in June 2011 (Credit: NASA/JPL-Caltech/Space Science Institute)
The two moons may look like they’re almost touching but in reality they were nearly half a million miles apart!
Titan’s northern “land of lakes” is visible in this image, captured by Cassini with a special spectral filter able to pierce through the moon’s thick haze:
Titan images by Cassini on Oct. 7, 2013 (Credit: NASA/JPL-Caltech/Space Science Institute)
The frozen, snowball-like surface of the 313-mile-wide moon Enceladus:
Enceladus: a highly-reflective and icy “snowball in space” (Credit: NASA/JPL-Caltech/Space Science Institute)
(Even though Enceladus is most famous for its icy geysers, first observed by Cassini in 2005, in these images they are not visible due to the lighting situations.)
Seen in a different illumination angle and in filters sensitive to UV, visible, and infrared light the many fractures and folds of Enceladus’ frozen surface become apparent:
View of the trailing face of Enceladus (Credit: NASA/JPL-Caltech/Space Science Institute)
Because of Cassini’s long-duration, multi-season stay in orbit around Saturn, researchers have been able to learn more about the ringed planet and its fascinating family of moons than ever before possible. Cassini is now going into its tenth year at Saturn and with much more research planned, we can only imagine what discoveries (and images!) are yet to come in the new year(s) ahead.
“Until Cassini arrived at Saturn, we didn’t know about the hydrocarbon lakes of Titan, the active drama of Enceladus’ jets, and the intricate patterns at Saturn’s poles,” said Linda Spilker, the Cassini project scientist at NASA’s Jet Propulsion Laboratory. “Spectacular images like these highlight that Cassini has given us the gift of knowledge, which we have been so excited to share with everyone.”
Hubble image of variable star RS Puppis (NASA, ESA, and the Hubble Heritage Team)
6,500 light-years away in the southern constellation Puppis an enormous star pulses with light and energy, going through the first throes of its death spasms as it depletes its last reserves of hydrogen necessary to maintain a stable, steady radiance. This star, a Cepheid variable named RS Puppis, brightens and dims over a 40-day-long cycle, and newly-released observations with Hubble reveal not only the star but also the echoes of its bright surges as they reflect off the dusty nebula surrounding it.
The image above shows RS Puppis shining brilliantly at the center of its dusty cocoon. (Click the image for a super high-res version.) But wait, there’s more: a video has been made of the variable star’s outbursts as well, and it’s simply mesmerizing. Check it out below:
Assembled from observations made over the course of five weeks in 2010, the video shows RS Puppis pulsing with light, outbursts that are then reflected off the structure of its surrounding nebula. What look like expanding waves of gas are really “light echoes,” radiation striking the densest rings of reflective dust located at farther and farther distances from the star.
According to the NASA image description:
RS Puppis rhythmically brightens and dims over a six-week cycle. It is one of the most luminous in the class of so-called Cepheid variable stars. Its average intrinsic brightness is 15,000 times greater than our sun’s luminosity.
The nebula flickers in brightness as pulses of light from the Cepheid propagate outwards. Hubble took a series of photos of light flashes rippling across the nebula in a phenomenon known as a “light echo.” Even though light travels through space fast enough to span the gap between Earth and the moon in a little over a second, the nebula is so large that reflected light can actually be photographed traversing the nebula. (Source)
RS Puppis is ten times more massive than our Sun, and 200 times larger.
Cepheid variables are more than just fascinating cosmic objects. Their uncanny regularity in brightness allows astronomers to use them as standard candles for measuring distances within our galaxy as well as others — which is trickier than it sounds. Because of its predictable variation along with the echoing light from its surrounding nebula, the distance to RS Puppis (6,500 ly +/- 90) has been able to be calculated pretty accurately, making it an important calibration tool for other such stars. (Read more here.)
Full image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-Hubble/Europe Collaboration. Acknowledgment: H. Bond (STScI and Penn State University)
