Dec 15 2015
From The Space Library
Release 15-235 NASA Examines Global Impacts of the 2015 El Niño
People the world over are feeling, or soon will feel, the effects of the strongest El Niño event since 1997-98, currently unfolding in the eastern equatorial Pacific Ocean. New satellite observations are beginning to show scientists its impact on the distribution of rain, tropospheric ozone and wildfires around the globe.
New results presented Tuesday at the American Geophysical Union meeting in San Francisco show that atmospheric rivers, significant sources of rainfall, tend to intensify during El Niño events, and this year's strong El Niño likely will bring more precipitation to California and some relief for the drought.
Due to this El Niño, tropospheric ozone, a pollutant and greenhouse gas, is seen decreasing over mid-latitude locations such as the United States, and the risk of fires across the tropics is showing signs of increasing.
An El Niño, which is a reoccurring natural phenomenon, happens when sea surface temperatures in the equatorial Pacific Ocean warm up. The increased ocean surface temperatures influence air and moisture movement around the globe. Approximately 15 years of observations by NASA's fleet of Earth-observing satellites show how El Niños affect multiple interconnected Earth systems.
One big question about the current El Niño is whether it will bring significant rainfall to drought-plagued California. Researchers studying storms and their relationship to strong El Niños believe it will.
Duane Waliser, chief scientist of the Earth Science and Technology Directorate at NASA's Jet Propulsion Laboratory in Pasadena, California, and his colleagues analyzed the historical record of atmospheric rivers. These concentrated rain bands account for 40 percent of California's water supply. Their results suggest the number of atmospheric rivers California receives will remain the same, at an average 10 per year, but they will be stronger, warmer and wetter.
"Overall we'll likely get more precipitation, but maybe less in terms of snowfall," Waliser said, adding that they may contribute to more flooding.
It’s the strength of the El Niño that determines its impact on total rainfall in California, said Martin Hoerling, a research meteorologist with the Earth Systems Research Laboratory at the National Oceanic and Atmospheric Administration in Boulder, Colorado. His group ran a statistical analysis of the relationship between past El Niño strength and precipitation.
"What we learned is weak El Niños don't necessarily change the odds of precipitation being much different from normal," said Hoerling. "The rare occurrence of a strong El Niño, like what we're currently experiencing, however, greatly increases the odds of a wet California winter."
El Niño's elevated sea surface temperatures shift rain patterns by affecting the temperature of the air above the ocean, which alters how winds and air masses circulate air around the planet.
The change in winds also affects the distribution of tropospheric ozone around the planet. Tropospheric ozone exists in the atmospheric layer closest to the surface and comprises ozone produced naturally and from human pollution. Ozone in the troposphere is a greenhouse gas and a health hazard. Understanding El Niño's influence on ozone concentration is important for understanding the atmosphere's response to natural variation and distinguishing natural changes from human causes.
Mark Olsen, an atmospheric research scientist at Morgan State University in Baltimore and NASA's Goddard Space Flight Center in Greenbelt, Maryland, and his colleagues produced the first near-global map of ozone sensitivity caused by El Niño and La Niña events. Previous work showed that El Niño events cause a strong change in ozone in the tropics. Olsen's new work uses satellite data combined with a computer model to show that a smaller but still significant effect occurs in the mid-latitudes.
"El Niño is just one factor in the variability," Olsen said. "But you do see regions like the central United States where El Niño explains 20 to 25 percent of the variability."
Ozone in this region tends to decrease where El Niño-driven changes to local wind circulation patterns causes them to draw air upward. According to Olsen, it's a large enough influence that El Niño does need to be considered if you want to attribute causes of ozone concentration changes and long-term trends.
Jim Randerson, Earth system scientist at the University of California, Irvine, and his team analyzed wildfire burned area maps from satellite data to study how El Niño-driven effects change the distribution and severity of wildfires worldwide. During El Niños, the number and size of fires increases in tropical forests across Asia and South America.
Fires in tropical forests also accelerate carbon dioxide buildup in the atmosphere and reduce air quality. Indonesia, for example, has carbon-rich peatlands that ignite as soon as the rain stops, which is what happened this fall, Randerson said. Meanwhile, Southeast Asia, Central America, and the southern Amazon have very high fire risk for 2016. El Niño tends to reduce rainfall in their wet seasons, and less rain means drier vegetation and drier air, which make forests vulnerable to dry season burning.
NASA uses the vantage point of space to increase our understanding of our home planet, improve lives, and safeguard our future. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.
Release 15-238 American, Russian and Briton Join International Space Station Crew
Hatches between the International Space Station and an arriving Soyuz spacecraft opened at 2:58 p.m. EST Tuesday, signaling the arrival of three new crew members, including NASA astronaut Tim Kopra. They will join other residents on the station to continue important research that advances NASA's journey to Mars, while making discoveries that can benefit all of humanity.
Kopra, Russian Federal Space Agency (Roscosmos) cosmonaut Yuri Malenchenko and ESA (European Space Agency) astronaut Tim Peake launched from the Baikonur Cosmodrome in Kazakhstan at 6:03 a.m. (5:03 p.m. in Baikonur) and, after orbiting Earth four times, manually docked to the station at 12:33 p.m.
The arrival of Kopra, Malenchenko and Peake returns the station's crew complement to six. The three join Expedition 46 Commander Scott Kelly of NASA and Flight Engineers Sergey Volkov and Mikhail Kornienko of Roscosmos. During more than five months on humanity’s only microgravity laboratory, the Expedition 46 crew members will conduct more than 250 science investigation in fields including biology, Earth science, human research, physical sciences and technology development.
Kopra, Malenchenko and Peake will remain aboard the station until early June 2016. Kelly and Kornienko will return to Earth at the conclusion of their one-year mission on March 1, 2016, along with Volkov. The pair will have spent 340 consecutive days living and working in space to advance understanding of the medical, psychological and biomedical challenges astronauts face during long duration spaceflight, in addition to developing countermeasures to reverse those effects.
Ongoing station research also includes the Microbial Payload Tracking Series project, which uses microbial analysis techniques to establish a census of the microorganisms living on surfaces and in the atmosphere of the space station. Along with crew members and experimental payloads, the space station is home to a variety of microbes, which are a cleaning nuisance and potentially threatening to crew health and station equipment. Analyzing these microbes can help determine whether some are more virulent in space, and which genetic changes might be involved in this response. Results from the investigation can be used to evaluate cleaning strategies, and to mitigate microbe-related risks to crew health and spacecraft system performance.
The crew members are scheduled to receive several cargo spacecraft -- including multiple U.S. commercial resupply vehicles from SpaceX and Orbital ATK -- each delivering tons of food, fuel, supplies and research.
SpaceX will deliver on its eighth commercial resupply services mission an important technology project that could help drive future exploration. Developed under a public-private partnership, the Bigelow Expandable Activity Module (BEAM) is an expandable habitat technology demonstration for the International Space Station. Expandable habitats can greatly decrease the amount of transport volume for future space missions, weighing less and taking up less room on a rocket. These habitats have the potential to provide a comfortable area for astronauts to live and work, as well as a varying degree of protection from solar and cosmic radiation, space debris and other elements of the space environment. Highly reliable habitation systems will be essential to keep future crews healthy and productive in the deep-space environment during missions in lunar orbit where the systems will be validated for future missions to Mars that could last as long as 1,100 days.
For 15 years, humans have been living continuously aboard the station to advance scientific knowledge and demonstrate new technologies, making research breakthroughs not possible on Earth that also will enable long-duration human and robotic exploration into deep space. A truly global endeavor, more than 200 people from 15 countries have visited the unique microgravity laboratory that has hosted more than 1,700 research investigations from researchers in more than 80 countries.
Meanwhile, in a galaxy not so far, far away…
The fantasy creations of the "Star Wars" universe are strikingly similar to real planets in our own Milky Way galaxy. A super Earth in deep freeze? Think ice-planet "Hoth." And that distant world with double sunsets can't help but summon thoughts of sandy "Tatooine."
No indications of life have yet been detected on any of the nearly 2,000 scientifically confirmed exoplanets, so we don't know if any of them are inhabited by Wookiees or mynocks, or play host to exotic alien bar scenes (or even bacteria, for that matter).
Still, a quick spin around the real exoplanet universe offers tantalizing similarities to several Star Wars counterparts.
A more ancient Earth?
The most recently revealed exoplanet possessing Earth-like properties, Kepler-452b, might make a good stand-in for Coruscant -- the high-tech world seen in several Star Wars films whose surface is encased in a single, globe-spanning city. Kepler-452b belongs to a star system 1.5 billion years older than Earth's. That would give any technologically adept species more than a billion-year jump ahead of us. The denizens of Coruscant not only have an entirely engineered planetary surface, but an engineered climate as well. On Kepler-452b, conditions are growing markedly warmer as its star's energy output increases, a symptom of advanced age. If this planet (which is 1.6 times the size of Earth) were truly Earth-like, and if technological life forms were present, some climate engineering might be needed there as well.
City in the sky
Mining the atmospheres of giant gas planets is a staple of science fiction. NASA, too, has examined the question, and found that gases such as helium-3 and hydrogen could be extracted from the atmospheres of Uranus and Neptune. Gas giants of all stripes populate the real exoplanet universe; in "The Empire Strikes Back," a gas giant called Bespin is home to a "Cloud City" actively involved in atmospheric mining. The toadstool-shaped city provides apparent refuge for a fleeing Princess Leia and company -- at least until Darth Vader wreaks his usual havoc.
Many of the gas giants found so far by instruments such as NASA's Kepler Space Telescope are so-called "hot Jupiters" -- star-hugging behemoths far too thoroughly barbecued to be proper sites for floating cities. One recent discovery, however, shows that gas "exogiants" can orbit their stars at distances remarkably similar to those in our solar system. An international astronomical team discovered a twin of our own Jupiter, orbiting its star at about the same distance as Jupiter is from the sun. The star, HIP 11915, is about the same age and composition as our sun, raising the possibility that its entire planetary system might be similar to ours. This not-so-hot Jupiter, about 186 light-years away from Earth, was detected using the 11.8-foot (3.6-meter) telescope at La Silla Observatory in Chile.
Bespin's atmospheric layers include a band of breathable air, ideal for floating cities. In our galaxy, emerging technology allows us to read out the components of real exoplanet atmospheres -- including gas giants (though so far none show signs of habitable layers). And tasting the atmospheres of smaller, rocky, potentially habitable exoplanets soon could be within reach. Astronomers using K2, the second planet-finding mission of the Kepler space telescope, recently detected three such planets orbiting a nearby dwarf star. The starlight shining through the atmospheres of these planets could reveal their composition in future observations.
Turn up the heat
The planet Mustafar, scene of an epic duel between Obi-Wan Kenobi and Anakin Skywalker in "Revenge of the Sith," has a number of exoplanet counterparts. These molten, lava-covered worlds, such as Kepler-10b and Kepler-78b, are rocky planets in Earth's size range whose surfaces could well be perpetual infernos. Kepler-78b, roughly 20 percent larger than Earth, weighs in at twice Earth's mass; a comparable density means it could be composed of rock and iron. That might make it, like Mustafar, suitable for mining, although its extremely tight orbit around its sun-like star, along with scorching temperatures, provides an unlikely arena for industrial operations -- or for fencing with lightsabers.
Kepler-10b isn't much more pleasant. The first rocky world discovered using the Kepler telescope, it also hugs its sun, some 20 times closer than Mercury orbits ours. A balmy day on Kepler-10b means daytime highs of more than 2,500 Fahrenheit (1,371 Celsius), even hotter than lava flowing on Earth. The surface, free of any kind of atmosphere, might be boiling with iron and silicates.
At 3,600 degrees Fahrenheit (1,982 Celsius), however, CoRoT-7b has Kepler-10b beat. This well-grilled planet, discovered in 2010 with France's CoRoT satellite, lies some 480 light-years away, and has a diameter 70 percent larger than Earth's, with nearly five times the mass. Possibly the boiled-down remnant of a Saturn-sized planet, its orbit is so tight that its star looms much larger in its sky than our sun appears to us, keeping its sun-facing surface molten.
Deep freeze
The planet OGLE-2005-BLG-390, nicknamed "Hoth," is a cold super-Earth that might be a failed Jupiter. Unable to grow large enough, it had to settle for a mass five times that of Earth and a surface locked in the deepest of deep freezes, with a surface temperature estimated at minus 364 degrees Fahrenheit (minus 220 Celsius). That most likely means no "Hoth"-style tauntauns to ride, or even formidably fanged abominable snowmen (aka "wampas"). Astronomers used an extraordinary planet-finding technique known as microlensing to find this world in 2005, one of the early demonstrations of this technique's ability to reveal exoplanets. In microlensing, backlight from a distant star is used to reveal planets around a star closer to us.
The planet lies toward the heart of the Milky Way, where a greater density of stars makes microlensing events more likely. The one-time event revealing the distant Hoth was captured by the Optical Gravitational Lensing Experiment, or OGLE, and confirmed by other instruments.
We won't have to travel 20,000 light years, however, to visit icy worlds. Saturn's smoggy moon, Titan, where the Cassini spacecraft's Huygens probe landed in 2005, is pocked with methane lakes and socked in permanently with thick, hydrocarbon haze. The freeze is so deep that water ice is no different from rock. Another Saturn moon, Enceladus, looks like a snowball but harbors a subsurface ocean much like Jupiter's moon Europa, another ice ball with a likely ocean underneath. That ocean would be warmed by tidal flexing as the little moon orbits Jupiter.
Sunset? Make it a double
Luke Skywalker's home planet, Tatooine, is said to possess a harsh, desert environment, swept by sandstorms as it roasts under the glare of twin suns. Real exoplanets in the thrall of two or more suns are even harsher. Kepler-16b was the Kepler telescope's first discovery of a planet in a "circumbinary" orbit -- circling both stars, as opposed to just one, in a double-star system. This planet, however, is likely cold, about the size of Saturn, and gaseous, though partly composed of rock. It lies outside its two stars' "habitable zone," where liquid water could exist. And its stars are cooler than our sun, and probably render the planet lifeless. Of course, we could look on the bright side (so to speak). When the discovery was announced in 2011, Bill Borucki, the now-retired NASA principal investigator for Kepler at Ames Research Center, Moffett Field, California, said finding the new planet might actually broaden the prospects for life in our galaxy. About half of all stars belong to binary systems, so the fact that planets form around these, as well as around single stars, can only increase the odds.
A more recently announced exoplanet, Kepler-453b, is also a circumbinary and a gas giant, though its orbit within its star's habitable zone means any moons it might have could be hospitable to life. It was the tenth circumbinary planet discovered using the Kepler telescope.
Ocean world
Kepler-22b, analog to the Star Wars planet Kamino (birthplace of the army of clone soldiers)), is a super-Earth that could be covered in a super ocean. Watery, storm-drenched Kamino makes its appearance in "Attack of the Clones."
The jury is still out on Kepler-22b's true nature; at 2.4 times Earth's radius, it might even be gaseous. But if the ocean world idea turns out to be right, we can envision a physically plausible Kamino-like planet, with the help of scientists at the Massachusetts Institute of Technology in Cambridge. An ocean world tipped on its side -- a bit like our solar system's ice giant, Uranus -- turns out to be comfortably habitable based on recent computer modeling. Researchers found that an exoplanet in Earth's size range, at a comparable distance from its sun and covered in water, could have an average surface temperature of about 60 degrees Fahrenheit (15.5 degrees Celsius). Because of its radical tilt, its north and south poles would be alternately bathed in sunlight and darkness, for half a year each, as the planet circled its star.
Scientists previously thought such a planet would seesaw between boiling and freezing, rendering it uninhabitable. But the MIT scientists' three-dimensional model showed that the planet, even with a relatively shallow ocean of about 160 feet (50 meters), would absorb heat during its odd polar summer and release it in winter. That would keep the overall climate mild and spring-like year round.
The shallow depth, by the way, would be ideal for Kamino-style ocean platforms, allowing construction of covered cities at the ocean surface, where armies of clones could march and drill in peace.
Fly me to the exomoon
Endor, the forested realm of the Ewoks, orbits a gas giant and was introduced in "Return of the Jedi." Detection of exomoons -- that is, moons circling distant planets -- is still in its infancy for scientists here on Earth. A possible exomoon was observed in 2014 via microlensing. It will remain forever unconfirmed, however, since each microlensing event can be seen only once. If the exomoon is real, it orbits a rogue planet, unattached to a star and wandering freely through space. The planet might have hung on to its moon after somehow being ejected during the early history of a forgotten planetary system. A team of Japanese, New Zealand, and American astronomers analyzed data gathered in 2011 with telescopes in New Zealand and Tasmania, and suggested the possible exomoon. They said a small star accompanied by a large planet also could have caused the same lensing effect.
More exomoons might soon be popping out from the depths of space. The Harvard-based Hunt for Exomoons with Kepler, or HEK, has begun to scour data from Kepler for signs of them. In early 2015, the researchers examined about 60 Kepler planets and determined that existing technology is sufficient to capture evidence of exomoons.
The hunt could have powerful implications in the search for life beyond Earth. If exomoons are shown to be potentially habitable, it would open another avenue for biology; habitable moons might even outnumber habitable planets. Could they have bustling ecosystems, with life forms even more exotic than Endor's living teddy bears, swinging between trees Tarzan-style? Stay tuned.
Breaking up is hard to do
In “A New Hope,” Princess Leia’s home planet, Alderaan, is blown to smithereens by the Empire’s Death Star as she watches in horror. Real exoplanets also can experience extreme destruction. A white dwarf star was caught in the act of devouring the last bits of a small planet in 2015, observed with the help of NASA's Chandra X-ray Observatory. White dwarfs are super-dense stellar remnants about the size of Earth, but with gravity more than 10,000 times that of our sun's surface. Tidal forces could rip a planet caught in its pull to shreds.
Observers thought at first they were seeing a black hole in the act of feeding inside a star cluster on the Milky Way's rim. X-ray observations, however, matched theoretical models of a planet being torn apart by a white dwarf.
A similar observation of a closer white dwarf was made by K2 in 2014. In this case, a tiny rocky object, probably an asteroid, was being vaporized into little more than a dusty ring as it whipped around the star every 4.5 hours.
NASA's Spitzer Space Telescope also picked up signs of debris from a likely asteroid collision in 2014. But rather than a sign of planetary destruction, the colliding asteroids could be part of a construction site. This young star -- about 1,200 light years away and only 35 million years old -- is surrounded by a ring of dust where such collisions are frequent. The smashed and broken bits fuse into larger and larger agglomerations, eventually forming full-sized planets.
Our own solar system might once have looked very similar, if anyone was watching.
NASA's Ames Research Center in Moffett Field, California, manages the Kepler and K2 missions for NASA's Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corp. operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.
JPL, a division of the California Institute of Technology in Pasadena, manages the Spitzer Space Telescope for NASA.
