A general rule of skygazing is that the farther you look, the less things change. Clouds? Different from one minute to the next. Moon? Phases shifting every night. Planets? You can easily see them move over the course of a week. But stars? Nah, they’re usually the same your whole lifetime. Usually.
Right now is one of the exceptions to that rule. Five days ago, amateur astronomer Koichi Itagaki of Yamagata, Japan was the first to report that a previously obscure star in the constellation Delphinus had suddenly skyrocketed in brightness, by a factor of 50,000, give or take. He recognized it as a nova explosion, now officially designated Nova Delphini 2013. If you act fast and have clear, dark skies you can see it for yourself. Nature has even kindly placed it in a convenient location, high in the east at sunset, with an arrow of stars (the small constellation Saggita–literally, “the arrow”) pointing right at it.
And if you have the bad luck to live near city lights, beside tall buildings, or just under cloudy skies, have no fear: The Internet will let you watch Nova Delphinus, either live or archived, as it slowly fades away back to its former, anonymous self. Read More
A conversation with NASA deputy administrator Lori Garver is always livelier than her title would suggest. Her enthusiasm for all things space is immediately evident, and she always seems on the verge of speaking more candidly than her position supposedly allows. She’s not entirely immune to the carefully crafted talking points typically served up by high-level government officials, but the punctuations in her speech—“wow” when excited, “frankly” when frustrated—strip away the veneer.
Lately, Garver has been using plenty of both words as she drums up support for NASA’s Asteroid Redirect Mission, a proposal to send a robotic spacecraft to a small near-Earth asteroid (perhaps about 15-20 feet wide), tow it back to a location near the moon, and send astronauts to study it. The concept has sparked a lot of public excitement, but also a fair bit of skepticism on Capital Hill, where the House Science Committee voted to block funding for the program. Read More
What’s up with that crazy giant hole on the sun? That’s the question I was addressing during my short appearance on Fox News last week. Or rather, it’s the question I was trying to address. My explanation contained a few poor word choices, which resulted in a confusing and misleading description of solar activity. That is the danger of live television: once a conversation goes off track, it’s hard to get back in real time, with only 100 seconds to go.
These days nothing on TV really vanishes, of course. My clip is preserved online, where anyone can react and critique it—and boy did I get some critiques. The good news is that the story of the hole on the sun is a fascinating one, and the queries and criticisms it inspired point the way to a much deeper understanding both of how the sun works and how it affects us here on Earth. I gave a lemon of an interview. Time to make some lemonade. Read More
This question came up as part of a new Q&A column running monthly in DISCOVER magazine. I love responding to reader queries; answering them in a meaningful way almost always leads to some interesting new ideas. (Got a burning science question of your own? Send it to Ask@DiscoverMagazine.com and we’ll try to answer it here or in a future issue of the magazine.)
On to the answer part. You might think that dark matter would be a significant factor when NASA plots the kind of trajectories that sent Cassini to Saturn, or the New Horizons spacecraft on its way to a 2015 rendezvous with Pluto. After all, dark matter seems to greatly outweigh the visible kind. But as with so many things in astronomy, human intuition turns out to be a poor guide. In reality, the effect of dark matter on a spacecraft within the solar system is basically zero — much smaller than the subtle effects of sunlight and solar wind, not to mention outgassing from equipment and heat radiated from the spacecraft itself. Read More
Earlier this week, the visionaries who operate NASA’s Cassini spacecraft released a remarkable snapshot of Earth as seen from Saturn. It got a ton of media attention, and rightly so. It is a stunning celestial view that no human being can see first-hand, but that billions of people around the world can now experience vicariously. It starkly illustrates how small we are within the universe, while simultaneously celebrating the grand things our little species is capable of. I went on cable news to talk about it, and DISCOVER blogger Tom Yulsman wrote a poignant post about it.
But that new Cassini image is far from the only perspective-busting picture that has come in from humanity’s space fleet. In fact, there is a whole portfolio, many of them rarely seen. Collectively they offer what I call an alien’s-eye view of Earth: They show what our planet might look like to extraterrestrial scientist scoping out our planet from afar. Here I’ve pulled together a few of my favorites. [To follow me on Twitter: @coreyspowell] Read More
For three decades, astronomers have been waging war with the air around them, and slowly winning. A succession of increasingly advanced technologies–under the name active optics, and more recently adaptive optics–compensated for the continuous blowing, flowing, shimmering, and general blurring of Earth’s atmosphere. These devices are not perfect, but they do a credible job sharpening the view. Essentially all of the world’s major observatories now use some system along those lines.
Now the engineers at the Gemini Observatory have taken blur-elimination technology a step beyond. They have just equipped the 8.1-meter Gemini South telescope, located atop Cerro Pachon in Chile, with a system called GeMS. The full name is a mouthful (Gemini Multi-Conjugate Adaptive Optics System) but its effect is straightforward: It compensates for atmospheric motions as they happen, allowing Gemini South to match the sharpness of the Hubble Space Telescope. In essence, astronomers flick a switch and the air disappears, making the view from a Chilean mountaintop almost exactly match the view from space. Read More
They come from somewhere in the distant universe–probably some 6 billion to 11 billion light years away. They don’t last very long, only about one-thousandth of a second. They happen all the time, up to 10,000 times a day. They create intense bursts of radio emission but nothing else–no light, no x-rays, no other visible evidence. And nobody knows what they are. Until now, nobody was even sure they existed.
Astronomers are calling these enigmatic signals “fast radio bursts” or “Lorimer bursts,” after Duncan Lorimer, the researcher who detected the first one. The timing of the press releases made me momentarily suspicious–a fireworks-type story that breaks on the 4th of July?–but a quick look a the discovery paper, published today in the journal Science, quickly dispelled my cynicism. This is the real deal: a genuine new cosmic mystery. Read More
Director Roland Emmerich is responsible for some of the most deliriously enjoyable abuses of science on the big screen: Independence Day’s dimwitted aliens, 2012’s physics-defying astrophysical disasters, and Jake Gyllenhaal’s panicked flight from homicidal tendrils of cold air in The Day After Tomorrow, which is one of cinema’s great unintentional comedy scenes.
Assuming it is unintentional, which is not at all clear with Emmerich. He always seems to be having a grand time skewering logic and ignoring the laws of physics, which strongly suggests he is in on the joke. So even though there’s no science-fiction premise to Emmerich’s latest movie, White House Down, I jumped at a chance to get a peek into his thought process.
Mickey Nelson, the recently retired Assistant Director of the Secret Service, offered his insights on the technology and techniques behind White House Down. That raised some additional possibilities. Would the secret service really relinquish on the “secret” part of its name? In the end, I learned a few things about the world of government security—just not quite what I expected. Read More
Like a really good book–or a really intense hangover–attending the World Science Festival is an experience that sticks with you. I took the plunge and joined back-to-back sessions, one on the nature of consciousness and other on the meaning of infinity. My head still hasn’t fully recovered, and that is exactly what I had hoped for.
Consciousness and infinity, more than any other topics (except maybe cosmology, and sure enough that eventually came up too), push at the outer limits of the human intellect. Making sense of consciousness is the ultimate inward-looking act; making sense of infinity is the ne plus ultra of looking out. Both are acts of profound transcendence. How can a finite brain comprehend the infinite? How can a mind that is trapped within a physical structure understand itself from the outside?
I hustled off to two New York University lecture halls to see if I could get some meaningful answers between 6 and 10PM on a Friday night. Read More
There are many way to celebrate your 70th birthday. You could sit down in front of a cake packed tight with flaming candles. You could go bowling with your buds wearing a T-shirt that says, “Over the hill–and picking up speed.” Or you could help put together the most amazing, three-dimensional map of the universe ever created.
Brent Tully opted for door #3.
Tully, a cosmologist at the University of Hawaii’s Institute for Astronomy, has probably done more than any other single living scientist to help uncover what the universe looks like in three dimensions. That’s no small challenge. As anyone knows from looking up a the night sky, appearances alone tell you almost nothing about which stars are near and which are far. The same goes for galaxies. Measuring their distances is so difficult that less than a century many astronomers doubted that other galaxies even existed. At the time, some of the leading researchers thought that what we now call galaxies were actually “spiral nebulae”–small, nearby clouds of gas that were turning into individual stars. That is the kind of challenge that Tully has taken on, with staggering results. Read More