Kawah Ijen, in Indonesia’s Ijen volcano complex, is the biggest “acidic volcanic crater lake” in the world. It also happens to emit lava which appears luminescent and electric-blue. The lava, like all other lava, starts out red. Then it hits the “pockets.” (Photos via @reubenwu)
In celebration of the 20th anniversary of the first confirmed planet around a sun-like star (aka exoplanet), a collection of some interesting exoplanets has been put together. Some of these are rocky, some are gaseous and some are very, very cold. But there’s one thing each these strange new worlds have in common: All have advanced scientific understanding of our place in the cosmos. Check out these 10 exoplanets, along with artist’s concepts depicting what they might look like. For an extended list of 20 exoplanets, go HERE.
1. Kepler-186f
Kepler-186f was the first rocky planet to be found within the habitable zone – the region around the host star where the temperature is right for liquid water. This planet is also very close in size to Earth. Even though we may not find out what’s going on at the surface of this planet anytime soon, it’s a strong reminder of why new technologies are being developed that will enable scientists to get a closer look at distance worlds.
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2. HD 209458 b (nickname “Osiris”)
The first planet to be seen in transit (crossing its star) and the first planet to have it light directly detected. The HD 209458 b transit discovery showed that transit observations were feasible and opened up an entire new realm of exoplanet characterization.
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3. Kepler-11 system
This was the first compact solar system discovered by Kepler, and it revealed that a system can be tightly packed, with at least five planets within the orbit of Mercury, and still be stable. It touched off a whole new look into planet formation ideas and suggested that multiple small planet systems, like ours, may be common.
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4. Kepler-16b
A real-life “Tatooine,” this planet was Kepler’s first discovery of a planet that orbits two stars – what is known as a circumbinary planet.
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5. 51 Pegasi b
This giant planet, which is about half the mass of Jupiter and orbits its star every four days, was the first confirmed exoplanet around a sun-like star, a discovery that launched a whole new field of exploration.
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6. CoRoT 7b
The first super-Earth identified as a rocky exoplanet, this planet proved that worlds like the Earth were indeed possible and that the search for potentially habitable worlds (rocky planets in the habitable zone) might be fruitful.
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7. Kepler-22b
A planet in the habitable zone and a possible water-world planet unlike any seen in our solar system.
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8. Kepler-10b
Kepler’s first rocky planet discovery is a scorched, Earth-size world that scientists believe may have a lava ocean on its surface.
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9. Kepler-444 system
The oldest known planetary system has five terrestrial-sized planets, all in orbital resonance. This weird group showed that solar systems have formed and lived in our galaxy for nearly its entire existence.
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10. 55 Cancri e
Sauna anyone? 55 Cancri e is a toasty world that rushes around its star every 18 hours. It orbits so closely – about 25 times closer than Mercury is to our sun – that it is tidally locked with one face forever blistering under the heat of its sun. The planet is proposed to have a rocky core surrounded by a layer of water in a “supercritical” state, where it is both liquid and gas, and then the whole planet is thought to be topped by a blanket of steam.
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Saturn V Cutaway ~ This fascinating Saturn V cutaway drawing is by far the most detailed I’ve ever come across. It’s an original, official Boeing engineering breakdown by Don Sprague and includes everything you ever wanted to know about the Saturn V’s internal workings – right down to millimetre accurate measurements …
Geophysicists call it the new core paradox: They can’t quite explain how the ancient Earth could have sustained a magnetic field billions of years ago, as it was cooling from its fiery birth.
Now, two scientists have proposed two different ways to solve the paradox. Each relies on minerals crystallizing out of the molten Earth, a process that would have generated a magnetic field by churning the young planet’s core. The difference between the two explanations comes in which particular mineral does the crystallizing.
Silicon dioxide is the choice of Kei Hirose, a geophysicist at the Tokyo Institute of Technology who runs high-pressure experiments to simulate conditions deep within the Earth. “I’m very confident in this,” he reported on 17 December at a meeting of the American Geophysical Union in San Francisco, California.
But David Stevenson, a geophysicist at the California Institute of Technology in Pasadena, says that magnesium oxide — not silicon dioxide — is the key to solving the problem. In unpublished work, Stevenson proposes that magnesium oxide, settling out of the molten early Earth, could have set up the buoyancy differences that would drive an ancient geodynamo.
The core paradox arose in 2012, when several research teams reported that Earth’s core loses heat at a faster rate than once thought1, 2. More heat conducting away from the core means less heat available to churn the core’s liquid. That’s important because some studies suggest Earth could have had a magnetic field more than 4 billion years ago — just half a billion years after it coalesced from fiery debris swirling around the newborn Sun. “We need a dynamo more or less continuously,” Peter Driscoll, a geophysicist at the Carnegie Institution for Science in Washington DC, said at the meeting.
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Entangled by gravity and destined to merge, two candidate black holes in a distant galaxy appear to be locked in an intricate dance. Researchers using data from NASA’s Galaxy Evolution Explorer (GALEX) and NASA’s Hubble Space Telescope have come up with the most compelling confirmation yet for the existence of these merging black holes and have found new details about their odd, cyclical light signal.
The candidate black hole duo, called PG 1302-102, was first identified earlier this year using ground-based telescopes. The black holes are the tightest orbiting pair detected so far, with a separation not much bigger than the diameter of our solar system. They are expected to collide and merge in less than a million years, triggering a titanic blast with the power of 100 million supernovae.
Researchers are studying this pair to better understand how galaxies and the monstrous black holes at their cores merge – a common occurrence in the early universe. But as common as these events were, they are hard to spot and confirm.
PG 1302-102 is one of only a handful of good binary black hole candidates. It was discovered and reported earlier this year by researchers at the California Institute of Technology in Pasadena, after they scrutinized an unusual light signal coming from the center of a galaxy. The researchers, who used telescopes in the Catalina Real-Time Transient Survey, demonstrated that the varying signal is likely generated by the motion of two black holes, which swing around each other every five years. While the black holes themselves don’t give off light, the material surrounding them does.
In the new study, published in the Sept. 17 issue of Nature, researchers found more evidence to support and confirm the close-knit dance of these black holes. Using ultraviolet data from GALEX and Hubble, they were able to track the system’s changing light patterns over the past 20 years.
What’s causing the changes in light? One set of changes has to do with the “blue shifting” effect, in which light is squeezed to shorter wavelengths as it travels toward us in the same way that a police car’s siren squeals at higher frequencies as it heads toward you. Another reason has to do with the enormous speed of the black hole.
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Orion is a key piece of NASA’s journey to Mars. The spacecraft, which was first tested in space last year, will enable crew to travel to deep space on the journey to the Red Planet and bring astronauts home safely. It’s a critical technology we’ll use to help NASA test, demonstrate and hone the skills and capabilities we need to operate farther and farther away from Earth.
Environmental Control and Life Support Systems
Water. Air. A temperate environment. A bathroom. These are some of the things astronauts need to survive the long journey back to Earth from Mars. NASA has developed an environmental control and life support system on the International Space Station and is designing such a system for Orion. The system can recycle carbon dioxide and make it back into useable air and process urine to make it into potable water, for example. Right now on the space station, engineers and astronauts are testing a filtering system for efficiency and reliability on long-duration missions. The investigation uses an amine-based chemical compound combined with the vacuum of space to filter and renew cabin air for breathing. When astronauts travel home from Mars, they won’t be able to count on the arrival of spare parts or extra supplies if something breaks or gets depleted, so engineers are hard at work developing reliable and robust technologies to keep crews alive and healthy in space.
Radiation protection
Astronauts traveling to and from Mars will be far away from the protective shield of Earth’s atmosphere and magnetic field, and their spacecraft and its systems will need to be able to protect against the full spectrum of space radiation. NASA is working now to develop protective methods.
Orion will use items already on board to protect the crew and create a temporary shelter in the aft bay of the spacecraft, which is the inside portion closest to the heat shield. This location minimizes the amount of equipment to move around while maximizing the amount of material that can be placed between the crew and the outside environment. The items that will be used include supplies, equipment and launch and re-entry seats as well as water and food. By using the items already on board, the astronauts benefit from additional shielding without adding to Orion’s mass.
Power and Propulsion
A spacecraft needs power and propulsion in space to refine its trajectory during the trip back to Earth. Orion will include a service module capable of helping the spacecraft make any necessary mid-course corrections. A service module provides power, heat rejection, in-space propulsion and water and air for crews, and NASA is working with ESA (European Space Agency) to provide Orion’s service module for its next mission in a partnership that will also bring international cooperation on the journey to Mars. The service module will provide propulsion, batteries and solar arrays to generate power and contain all the air, nitrogen and water for crews.
The ESA-provided element brings together new technology and lightweight materials while also taking advantage of spaceflight-proven hardware. For example, ESA is modeling several key components – like the solar arrays – from technology developed for its Automated Transfer Vehicle-series of cargo vessels, which delivered thousands of pounds of supplies to the space station during five missions between 2008 and 2015. NASA is providing ESA one of the Orbital Maneuvering System pods that allowed space shuttles to move in space to be upgraded and integrated into the service module.
Heat shield
When an uncrewed Orion was tested in space in 2014, the heat shield withstood temperatures of about 4,000 degrees Fahrenheit, or about twice as hot as molten lava. That heat was generated when the spacecraft, traveling at about 20,000 mph back toward our planet, made its way through Earth’s atmosphere, which acts as a braking mechanism to cause friction and slow down a returning spacecraft. Its speed was about 80 percent of what Orion will experience when it comes back from missions near the moon and will need to be even more robust for missions where return speeds, and therefore reentry temperatures, are higher.
Orion’s heat shield is built around a titanium skeleton and carbon fiber skin that provide structural support. A honeycomb structure fits over the skin with thousands of cells that are filled with a material called Avcoat. That layer is 1.6 inches at its thickest and erodes as Orion travels through Earth’s atmosphere.
Parachutes
A spacecraft bringing crews back to Earth after a long trip to Mars will need a parachute system to help it slow down from its high-speed reentry through the atmosphere to a relatively slow speed for splashdown in the ocean. While Earth’s atmosphere will initially slow Orion down from thousands of miles per hour to about 325 mph, its 11 parachutes will deploy in precise sequence to further slow the capsule’s descent. There are three forward bay cover parachutes that pull a protective cover off the top of the capsule, two drogue parachutes that deploy to stabilize the spacecraft, and three pilot parachutes that are used to pull out Orion’s three orange and white main parachutes that are charged with slowing the spacecraft to its final landing speed. The main parachutes are so big that the three of them together nearly cover an entire football field.
Engineers are currently building the Orion spacecraft that will launch on the world’s most powerful rocket, the Space Launch System, and will enable astronauts to travel farther into space than ever before on the journey to Mars.
Visit NASA on the Web for more information about Orion and NASA’s journey to Mars. http://www.nasa.gov/orion
Astronomers have found compelling signs for a supermassive black hole in the center of almost every large galaxy they have scrutinized, and the Milky Way is no exception. The core of our galaxy harbors an object called Sagittarius A* (pronounced A-star) — a black hole with about 4 million times the Sun’s mass. It’s the 19th confirmed black hole in the Milky Way, and it sits dead in the center.
The evidence takes several forms. First, intense radio waves and X-rays flow from an accretion disk that spans a region no bigger than our solar system. But the proof comes from careful tracking of the motions of stars as they orbit the central mass. It’s the same method astronomers use to hunt for globular cluster black holes, but the huge size of the object in the Milky Way’s heart makes these motions far easier to see. Analyzing the stellar orbits leads directly to the black hole’s mass.
The count of black holes in our galaxy likely will continue to grow in the years ahead, but it never will outpace the flood of planet discoveries. The ability to find planets has reached the stage where it’s surprising when a week goes by without a new detection. Black holes hide their identities much better, either behind the cloak of an event horizon or in isolation from other objects. Perhaps the biggest surprise in the study of our galaxy’s black holes is that we’ve already found 19.
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@rasinblazin
(photos by Robdogbird)
"I don't know who will read this. I guess someone will find it eventually. Maybe in a hundred years or so." -Mark Watney
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