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But they were surprised when they realized where the antimatter came from, not from some black hole light-years across the galaxy, but rather from our own planet. The source was a thunderstorm just 3,000 miles away. Earth's magnetic field seems to have corralled about 100 trillion positrons from the storm into a tight beam and funneled them all the way to the spacecraft, explains lightning expert Joseph Dwyer of the Florida Institute of Technology. Something was producing antimatter above the clouds of Earth and hurling it into space at nearly the speed of light. But what? Dwyer and collaborators at the NASA Marshall Space Flight Center and the University of Alabama believe they have figured it out. The answer, says Dwyer, is dark lightning.

Maybe that's why, when the morning sky lit up with a second sun and a shockwave shattered windows in hundreds of buildings around Chelyabinsk, only a few people picking themselves off the ground figured it out right away. This was not a crashing plane or a rocket attack. It was a meteor strike, the most powerful since the Tunguska event of 1908, says Bill Koch of NASA's Meteoroid Environment Office. In a one-in-a-million coincidence that still has NASA experts shaking their heads, a small asteroid completely unrelated to 2012 DA14 struck Earth only hours before the publicized event. These are rare events, and it is incredible to see them happening on the same day, says Paul Chodas of NASA's Near-Earth Object Program at JPL.

The most telling information came from a network of infrasound sensors operated by the Comprehensive Test Ban Treaty Organization. Their purpose is to monitor nuclear explosions. Infrasound is a type of very low frequency sound wave that only elephants, homing pigeons, and a few other animals can hear. It turns out that meteors entering Earth's atmosphere cause ripples of infrasound to spread through the air of our planet. By analyzing infrasound records, it is possible to learn how long a meteor was in the air, which direction it traveled, and how much energy it unleashed. The Russian meteor's infrasound signal was detected by multiple stations, including one in Alaska more than 6,500 kilometers from Chelyabinsk. Western Ontario professor of physics Peter Brown analyzed the data. The asteroid was about 17 meters in diameter and weighed approximately 10,000 metric tons, he reports. It struck Earth's atmosphere at 40,000 miles per hour and broke apart about 12 to 15 miles above Earth's surface. the energy of the resulting explosion exceeded 470 kilotons of TNT.

Recently, Williams and colleagues were doing a space station experiment called FLEX to learn how to put out fires in microgravity when they came across something odd. Small droplets of heptane were burning inside the FLEX combustion chamber. As planned, the flames went out. But unexpectedly, the droplets of fuel continued burning. That's right, burning without flames, says Williams. At first, we didn't believe it ourselves. In fact, Williams believes the flames are there, just too faint to see. These are cool flames, he explains. Ordinary visible fire burns at a high temperature between 2200 and 3100 degrees Fahrenheit. Heptane flameballs on the space station started out in this hot-fire regime, but as the flameballs cooled and began to go out, a different kind of burning took over. Cool flames burn at the relatively low temperature of 400 to 1,000 degrees Fahrenheit, says Williams, and their chemistry is completely different. Normal flames produce soot, carbon dioxide, and water. Cool flames produce carbon monoxide and formaldehyde. Similar cool flames have been produced on Earth, but they flicker out almost immediately. On the space station, however, cool flames can burn for nearly a minute.

But what happens when you light a candle, say, on the International Space Station? In microgravity, flames burn differently. They form little spheres, says Williams. Space station flameballs turn out to be wonderful mini-labs for combustion research. Unlike flames on Earth, which expand greedily when they need more fuel, flameballs let the oxygen come to them. Oxygen and fuel combine in a narrow zone at the surface of the sphere, not hither and yon throughout the flame. It's a much simpler system.

Forty light-years from Earth, a rocky world named 55 Cancri e circles perilously close to a stellar inferno. Completing one orbit in only 18 hours, the alien planet is 26 times closer to its parent star than Mercury is to the Sun. If Earth were in the same position, the soil beneath our feet would heat up to about 3200 degrees Fahrenheit. Researchers have long thought that 55 Cancri e must be a wasteland of parched rock. Now they're thinking again. New observations by NASA's Spitzer Space Telescope suggest that 55 Cancri e may be wetter and weirder than anyone imagined. Spitzer recently measured the extraordinarily small amount of light 55 Cancri e blocks when it crosses in front of its star.

The Voyager probes have entered a strange realm of frothy magnetic bubbles, says Marav Ofer of Boston University. This is very surprising. The bubbles are large, about 100 million miles wide, so it takes the speedy probes a whole year just to cross a few of them. Voyager 1 entered the foam zone in 2007, and Voyager 2 followed about a year later. At first, researchers didn't understand what the Voyagers were sensing, but now they have a good idea. The Sun's magnetic field extends all the way to the edge of the solar system, explains Ofer. Because the Sun spins, its magnetic field becomes twisted and wrinkled, a bit like a ballerina's skirt. Far, far away from the Sun, where the Voyagers are now, the folds of the skirt bunch up. When a magnetic field gets severely folded like this, interesting things can happen. Lines of magnetic force crisscross and reconnect. The crowded folds of the skirt reorganize themselves, sometimes explosively, into foamy magnetic bubbles. We never expected to find such a foam at the edge of the solar system, but there it is, says Offers colleague astronomer Jim Drake of the University of Maryland.

surprise birthday party for his husband, boyfriend. By him for me. Oh, it was for you? Okay. So it was a little murky what time we were supposed to be there from my point of view. From my point of view, it was a little murky what time we were supposed to be there. So I get there, let's say, at 8.15, at which point John and his husband, we'll call him Ronan, arrive. Ronan and Mary, yeah, we were in a long-term relationship, yeah. and I'm on the sidewalk, at which point I just hide behind a giant tree. Yeah, and whenever I think of you, I do think of that. It was, you failed so, your hiding was so funny because at first you didn't, to be clear, you didn't just hide behind a tree. At first you froze as if I was the T-Rex from Jurassic Park, like my vision only worked with motion. Keep absolutely still. And then you jumped back behind the tree, which I saw in full. Like, I just saw the whole thing happen. Head to toe. And it was a delightful memory.

A neutron star comes from a large star that has run out of fuel and exploded as a supernova. As gravity forces the star to collapse to the size of a small city, the star becomes so dense that a single teaspoon of the collapsed star would have as much mass as a mountain. The star's core, now a neutron star, can be rotating as fast as 10 times a second or more.

yeah well it's it's a it's a couple things one if i stand up to them i might lose and that's fucking humiliating then if i stand up to them it might make it worse and now i'm in a bigger confrontation yeah that's terrifying uh and but sometimes rarely it has turned out with a happy ending i had a guy i'm not gonna say who comic so mean to me when i started like unnecessarily mean weirdly mean picked on me, insulted me. The whole thing would heckle me during shows. And I was like, man, is this how comedy is? And he went to rehab, yada, yada. Years later, he wrote me this email like, I was jealous of you. I didn't know how to handle it. You wrote jokes that were better than mine and that bothered me. I was so mad at you, but I hate myself. And I was like, oh my God, I can't believe this. This is like everything I kind of maybe thought, but then I didn't want to believe because I'm like, oh, who's jealous of me, whatever. And it was a huge moment in my life seeing that.

It turns out that they do, sort of. and a NASA-funded researcher at the University of Iowa has figured out how to find them. We call them X-points, or electron diffusion regions, explains plasma physicist Jack Scudder of the University of Iowa. They're places where the magnetic field of Earth connects to the magnetic field of the Sun, creating an uninterrupted path leading from our own planet to the Sun's atmosphere 93 million miles away. Observations by NASA's Themis spacecraft and Europe's Cluster probes suggest that these magnetic portals open and close dozens of times each day. They're typically located a few tens of thousands of kilometers from Earth, where the geomagnetic field meets the onrushing solar wind. Most portals are small and short-lived. Others are yawning, vast, and sustained. energetic particles can flow through the openings, heating Earth's upper atmosphere, sparking geomagnetic storms, and igniting bright polar auroras.

Magnetic portals are invisible, unstable, and elusive. They open and close without warning, and there are no signposts to guide us in, notes Scudder. Actually, there are signposts, and Scudder has found them. Portals form via the process of magnetic reconnection. Mingling lines of magnetic force from the Sun and Earth crisscross and join to create the openings. X-points are where the crisscross takes place. The sudden joining of magnetic fields can propel jets of charged particles from the X-point, creating an electron diffusion region. To learn how to pinpoint these events, Scudder looked at data from a space probe that orbited Earth more than 10 years ago. In the late 1990s, NASA's Polar spacecraft spent years in Earth's magnetosphere, explains Scudder, and it encountered many X-points during its mission. Because Polar carried sensors similar to those of MMS, Scudder decided to see how an X-point looked to Polar. Using Polar data, we have found five simple combinations of magnetic field and energetic particle measurements that tell us when we've come across an X-point or an electron diffusion region. A single spacecraft, properly instrumented, can make these measurements.

Myth 4. Once inside a black hole, nothing ever comes out. Nope. It turns out that radiation can escape from a black hole. One of Stephen Hawking's contributions was a theory that a black hole is not so dense in a quantum mechanical sense. The slow leak of what's now known as Hawking radiation would, over time, cause the black hole to simply evaporate. The image from the Event Horizon Telescope confirmed what Albert Einstein's General Theory of Relativity predicted over 100 years ago – that a black hole's form is that of a perfect circle. And as scientists learn even more about the properties of this gigantic cosmic mystery we call a black hole, they'll be able to puncture even more myths.

Myth 3. If you get within a few thousand miles of a black hole, its supergravity will pull you into its center. It turns out, you can get surprisingly close to a black hole. If you approached a black hole with a mass equal to our sun's, for example, you could get as close as tens of miles. So, imagine if we replaced our sun with a black hole of the same mass. all of the planets would continue to revolve around it at exactly the same speed and distance as they do now.

Myth 2. All black holes are about the same size. Black holes actually come in several different sizes which are defined by their mass. Small black holes are usually the result of a relatively short and violent collapse of a star. Recent work suggests that intermediate black holes are found in the nuclei of some active galaxies. Supermassive black holes, on the other hand, are found at the center of nearly every galaxy. Dr. Dan Evans, an astrophysicist at NASA headquarters, says, There's a direct relationship between the beginning of supermassive black holes and the beginning of their corresponding galaxy. This strongly suggests the two were born about the same time and slowly grew in size together over billions of years.

Presented by Science at NASA Somewhere in the Milky Way, a massive star is about to die a spectacular death. As its nuclear fuel runs out, the star begins to collapse under its own tremendous weight. Crushing pressure triggers new nuclear reactions, setting the stage for a terrifying blast. And then, nothing happens. At least that's what supercomputers have been telling astrophysicists for decades. Many of the best computer models of supernovas fail to produce an explosion. At the end of the simulation, gravity wins the day and the star simply collapses. Clearly, physicists are missing something. We don't fully understand how supernovas of massive stars work yet, says Fiona Harrison, an astrophysicist at the California Institute of Technology. To figure out what's going on, scientists need to examine the inside of a real supernova while it's exploding. Not a particularly easy thing to do. So instead, they examine the remnant of the exploded star as soon after the explosion as possible. Harrison and colleagues have figured out how to do this using a new space telescope called the Nuclear Spectroscopic Telescope Array, NUSTAR for short.

For the three-day period, March 8-10, the thermosphere absorbed 26 billion kilowatt-hours of energy. Infrared radiation from CO2 and NO, the two most efficient coolants in the thermosphere, re-radiated 95% of that total back into space. In human terms, this is a lot of energy. According to the New York City mayor's office, an average New York household consumes just under 4,700 kilowatt hours annually. This means the geomagnetic storm dumped enough energy into the atmosphere to power every home in the Big Apple for two years. Unfortunately, there's no practical way to harness this kind of energy, says Milincek. It's so diffuse and out of reach high above the Earth's surface. Plus, the majority of it has been sent back into space by the action of CO2 and NO.

Why is the Milky Way's supermassive black hole such a picky eater? Compared to the giant black holes at the centers of other galaxies, the Milky Way is relatively quiet. More active black holes tend to gobble up matter in prodigious quantities. Ours, on the other hand, is thought only to nibble or not eat at all. Asteroids could be a primary food source. One model holds that trillions of asteroids surround the Milky Way's core. Astronomers using the Chandra X-ray Observatory have indeed detected flares consistent with asteroids 10 kilometers wide, or larger, falling into the black hole. These space rocks would be about the same size as the asteroid that wiped out the dinosaurs on Earth 65 million years ago.

Astronauts aboard the International Space Station, however, are experimenting with a form of water that does the opposite. Instead of stopping fire, this water helps start it. We call it supercritical water, says Mike Hicks of NASA's Glenn Research Center in Ohio. And it has some interesting properties. Water becomes supercritical when it is compressed to a pressure of 217 atmospheres and heated above 703.4 degrees Fahrenheit. Above that so-called critical point, ordinary H2O transforms into something that is neither solid, liquid, nor gas. It's more of a liquid-like gas. When supercritical water is mixed with organic material, a chemical reaction takes place. Oxidation, says Hicks. It's a form of burning without flames. This really comes in handy when you want to get rid of certain unpleasant materials, like sewage. Cities, corporate farms, ships at sea, and manned spacecraft accumulate waste materials that could benefit from this kind of treatment. When we push a wet waste stream above the critical point, supercritical water breaks the bonds of the hydrocarbons. Then they can react with oxygen. In other words, the slurry ignites. Sometimes, hot spots in the slurry produce visible flame, but usually not. This is a relatively clean form of burning that produces pure water and carbon dioxide, but none of the toxic products of ordinary fire.

But if that's true, what was space physicist Don Gurnett talking about last month when he stated at a NASA press conference that he had heard the sounds of interstellar space? It turns out that space can make music if you know how to listen. Gurnett is the James Van Allen Professor of Physics at the University of Iowa and the principal investigator for the plasma wave science instrument on Voyager 1. At the press conference, he played some plasma wave data for the audience. The sounds, he explained, were solid evidence that Voyager 1 had left the heliosphere.

Strictly speaking, the plasma wave instrument does not detect sound. Instead, it senses waves excited by electrons in the ionized gas or plasma that Voyager travels through. No human ear could hear these plasma waves. Nevertheless, because they occur at audio frequencies between a few hundred and a few thousand hertz, we can play the data through a loudspeaker and listen, says Gurnett, the pitch and frequency tell us about the density of gas surrounding the spacecraft. When Voyager 1 was inside the heliosphere, the tones were low, around 300 Hz, typical of plasma waves coursing through the rarefied solar wind. Outside, the frequency jumped to a higher pitch, between 2 and 3 kHz, corresponding to denser gas in the interstellar medium. The transition was music to Gurnett's ears.