Perseid Meteor Shower 2016

In this 30 second exposure, a meteor streaks across the sky during the annual Perseid meteor shower Friday, August 12, 2016 in Spruce Knob, West Virginia, USA

The Perseids show up every year in August when Earth ventures through trails of debris left behind by an ancient comet. This year, Earth may be in for a closer encounter than usual with the comet trails that result in meteor shower, setting the stage for a spectacular display.

Image Credit: NASA/Bill Ingalls

Pleiades

This image shows the famous Pleiades cluster of stars as seen through the eyes of WISE, or NASA's Wide-field Infrared Survey Explorer. The mosaic contains a few hundred image frames -- just a fraction of the more than one million WISE has captured so far as it completes its first survey of the entire sky in infrared light.

The Pleiades are what astronomers call an open cluster of stars, meaning the stars are loosely bound to each other and will eventually, after a few hundred million years, go their separate ways. The cluster is prominent in the sky during winter months in the constellation Taurus, when viewed from the Northern Hemisphere. Often called the Seven Sisters from Greek tradition, this cluster of stars has been named by cultures the world over: Parveen in Persian; Tianquiztli in the Aztec tradition, and Subaru in Japan. The Pleiades is even the logo of the automotive company that bears its Japanese name.

In this infrared view of the Pleiades from WISE, the cluster is seen surrounded by an immense cloud of dust. When this cloud was first observed, it was thought to be leftover material from the formation of the cluster. However, studies have found the cluster to be about 100 million years old -- any dust left over from its formation would have long dissipated by this time, from radiation and winds from the most massive stars. The cluster is therefore probably just passing through the cloud seen here, heating it up and making it glow.

At a distance of about 436 light-years from Earth, the Pleiades is one of the closest star clusters and plays an important role in determining distances to astronomical bodies further away. This picture from WISE covers an area of 3.05 by 2.33 degrees, which is the roughly the same area on the sky that a grid of six full moons by 4.7 full moons would occupy. Most of the stars in the cluster fall within the 20-light-year-wide region shown here.

All four infrared detectors aboard WISE were used to make this mosaic. Color is representational: blue and cyan represent infrared light at wavelengths of 3.4 and 4.6 microns, which is dominated by light from stars. Green and red represent light at 12 and 22 microns, which is mostly light from warm dust.

Image Credit: NASA/JPL-Caltech/UCLA
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA13121

Artist’s impression of the heating mechanism from Jupiter’s Great Red Spot

New NASA-funded research suggests that Jupiter’s Great Red Spot may be the mysterious heat source behind Jupiter’s surprisingly high upper atmospheric temperatures.

Here on Earth, sunlight heats the atmosphere at altitudes well above the surface—for example, at 250 miles above our planet where the International Space Station orbits. Scientists have been stumped as to why temperatures in Jupiter’s upper atmosphere are comparable to those found at Earth, yet Jupiter is more than five times the distance from the sun. They wanted to know: if the sun isn’t the heat source, then what is?

Researchers from Boston University’s Center for Space Physics set out to solve the mystery by mapping temperatures well above Jupiter’s cloud tops using observations from Earth. They analyzed data from the SpeX spectrometer at NASA’s Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, a 3-meter infrared telescope operated for NASA by the University of Hawaii. By observing non-visible infrared light hundreds of miles above the gas giant, scientists found temperatures to be much higher in certain latitudes and longitudes in Jupiter’s southern hemisphere, where the spot is located.

“We could see almost immediately that our maximum temperatures at high altitudes were above the Great Red Spot far below—a weird coincidence or a major clue?” said Boston University’s James O’Donoghue, lead author of the study.

The study, in the July 27 issue of the journal Nature, concludes that the storm in the Great Red Spot produces two kinds of turbulent energy waves that collide and heat the upper atmosphere. Gravity waves are much like how a guitar string moves when plucked, while acoustic waves are compressions of the air (sound waves). Heating in the upper atmosphere 500 miles (800 kilometers) above the Great Red Spot is thought to be caused by a combination of these two wave types “crashing,” like ocean waves on a beach.

“The extremely high temperatures observed above the storm appear to be the ‘smoking gun’ of this energy transfer,” said O’Donoghue. “This tells us that planet-wide heating is a plausible explanation for the ‘energy crisis,’ a problem in which upper-atmospheric temperatures are measured hundreds of degrees hotter than can be explained by sunlight alone.”

This effect has been observed over the Andes Mountains here on Earth and may also be happening elsewhere in the outer solar system, though it has not been directly observed. Scientists believe this phenomenon also occurs on giant exoplanets orbiting other stars.

The Great Red Spot (GRS) has delighted and mystified since its discovery in the 17th Century. With its swirl of reddish hues, it’s 2-3 times as wide as Earth and is seen by many as a “perpetual hurricane,” with winds peaking at about 400 miles an hour.

NASA's Juno spacecraft, which recently arrived at Jupiter, will have several opportunities during its 20-month mission to observe the Great Red Spot and the turbulent region surrounding it. Juno will peer hundreds of miles downward into the atmosphere with its microwave radiometer, which passively senses heat coming from within the planet. This capability will enable Juno to reveal the deep structure of the Great Red Spot, along with other prominent Jovian features, such as the colorful cloud bands.

Image Credit: Karen Teramura, UH IfA with James O’Donoghue and Luke Moore
Explanation from: https://www.nasa.gov/feature/jupiter-s-great-red-spot-likely-a-massive-heat-source

H II Region NGC 2174

The NASA/ESA Hubble Space Telescope has imaged a violent stellar nursery called NGC 2174, in which stars are born in a first-come-first-served feeding frenzy for survival.

The problem is that star formation is a very inefficient process; most of the ingredients to make stars are wasted as the cloud of gas and dust, or nebula, gradually disperses. In NGC 2174, the rate at which the nebula disperses is further speeded up by the presence of hot young stars, which create high velocity winds that blow the gas outwards.

These fiery youngsters also bombard the surrounding gas with intense radiation, making it glow brightly, creating the brilliant scene captured here. The nebula is mostly composed of hydrogen gas, which is ionised by the ultraviolet radiation emitted by the hot stars, leading to the nebula’s alternative title as an HII region. This picture shows only part of the nebula, where dark dust clouds are strikingly silhouetted against the glowing gas.

NGC 2174 lies about 6400 light-years away in the constellation of Orion (The Hunter). It is not part of the much more familiar Orion Nebula, which lies much closer to us. Despite its prime position in a very familiar constellation this nebula is faint and had to wait until 1877 for its discovery by the French astronomer Jean Marie Edouard Stephan using an 80 cm reflecting telescope at the Observatoire de Marseille.

This picture was created from images from the Wide Field Planetary Camera 2 on Hubble. Images through four different filters were combined to make the view shown here. Images through a filter isolating the glow from ionised oxygen (F502N) were coloured blue and images through a filter showing glowing hydrogen (F656N) are green. Glowing ionised sulphur (F673N) and the view through a near-infrared filter (F814W) are both coloured red. The total exposure times per filter were 2600 s, 2600 s, 2600 s and 1000 s respectively and the field of view is about 1.8 arcminutes across.

Image Credit: ESA/Hubble & NASA
Explanation from: https://www.spacetelescope.org/images/potw1106a/

NASA’s Next Planet Hunter Will Look Closer to Home

As the search for life on distant planets heats up, NASA’s Transiting Exoplanet Survey Satellite (TESS) is bringing this hunt closer to home. Launching in 2017-2018, TESS will identify planets orbiting the brightest stars just outside our solar system using what’s known as the transit method.

When a planet passes in front of, or transits, its parent star, it blocks some of the star's light. TESS searches for these telltale dips in brightness, which can reveal the planet's presence and provide additional information about it.

TESS will be able to learn the sizes of the planets it sees and how long it takes them to complete an orbit. These two pieces of information are critical to understanding whether a planet is capable of supporting life. Nearly all other planet classifications will come from follow up observations, by both TESS team ground telescopes as well as ground- and space-based observations, including NASA's James Webb Space Telescope launching in 2018.

Compared to the Kepler mission, which has searched for exoplanets thousands to tens of thousands of light-years away from Earth towards the constellation Cygnus, TESS will search for exoplanets hundreds of light-years or less in all directions surrounding our solar system.

TESS will survey most of the sky by segmenting it into 26 different segments known as tiles. The spacecraft's powerful cameras will look continuously at each tile for just over 27 days, measuring visible light from the brightest targets every two minutes. TESS will look at stars classified as twelfth apparent magnitude and brighter, some of which are visible to the naked eye. The higher the apparent magnitude, the fainter the star. For comparison, most people can see stars as faint as sixth magnitude in a clear dark sky and the faintest star in the Big Dipper ranks as third magnitude.

Among the stars TESS will observe, small bright dwarf stars are ideal for planet identification, explained Joshua Pepper, co-chair of the TESS Target Selection Working Group. One of the TESS science goals is to find Earth- and super-Earth-sized planets. These are difficult to discover because of their small size compared to their host stars, but focusing TESS on smaller stars makes finding these small planets much easier. This is because the fraction of the host star's light that a planet blocks is proportional to the planet’s size.

Scientists expect TESS to observe at least 200,000 stars during the two years of its spaceflight mission, resulting in the discovery of thousands of new exoplanets.

While the search for transiting exoplanets is the primary goal of the mission, TESS will also make observations of other astrophysical objects through the Guest Investigator (GI) Program. Because TESS is conducting a near all-sky survey, it has the capability to perform interesting studies on many different types of astronomical target.

“The goal of the GI Program is to maximize the amount of science that comes out of TESS,” said Padi Boyd, director of the Guest Investigator Program Office at NASA’s Goddard Space Flight Center. "Although TESS was designed to be capable of detecting planets transiting in front of stars, its unique mission characteristics mean that the potential science TESS can do includes far more than just exoplanets.” According to Boyd, the broad range of objects TESS could detect as part of the GI Program include flaring young stars, binary pairs of stars, supernovae in nearby galaxies, and even supermassive black holes in distant active galaxies. “We hope the broader science community will come up with many unique science ideas for TESS, and we hope to encourage broad participation from the larger community,” she said.

With the potential to expand our knowledge of the universe for years to come, researchers are excited about the potential discoveries TESS could bring.

“The cool thing about TESS is that one of these days I’ll be able to go out in the country with my daughter and point to a star and say ‘there’s a planet around that one,” said TESS Project Scientist Stephen Rinehart.

Image Credit: NASA's Goddard Space Flight Center
Explanation from: https://www.nasa.gov/feature/goddard/2016/nasas-tess-the-next-exoplanet-explorer

Globular Cluster NGC 4833

Located approximately 22 000 light-years away in the constellation of Musca (The Fly), this tightly packed collection of stars — known as a globular cluster — goes by the name of NGC 4833. This NASA/ESA Hubble Space Telescope image shows the dazzling stellar group in all its glory.

NGC 4833 is one of the over 150 globular clusters known to reside within the Milky Way. These objects are thought to contain some of the oldest stars in our galaxy. Studying these ancient cosmic clusters can help astronomers to unravel how a galaxy formed and evolved, and give an idea of the galaxy’s age.

Globular clusters are responsible for some of the most striking sights in the cosmos, with hundreds of thousands of stars congregating in the same region of space. Hubble has observed many of these clusters during its time in orbit around our planet, each as breathtaking as the last.

Image Credit: ESA/Hubble and NASA
Explanation from: https://www.spacetelescope.org/images/potw1631a/

NASA Climate Modeling Suggests Venus May Have Been Habitable

Venus may have had a shallow liquid-water ocean and habitable surface temperatures for up to 2 billion years of its early history, according to computer modeling of the planet’s ancient climate by scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York.

The findings, published this week in the journal Geophysical Research Letters, were obtained with a model similar to the type used to predict future climate change on Earth.

“Many of the same tools we use to model climate change on Earth can be adapted to study climates on other planets, both past and present,” said Michael Way, a researcher at GISS and the paper’s lead author. “These results show ancient Venus may have been a very different place than it is today.”

Venus today is a hellish world. It has a crushing carbon dioxide atmosphere 90 times as thick as Earth’s. There is almost no water vapor. Temperatures reach 864 degrees Fahrenheit (462 degrees Celsius) at its surface.

Scientists long have theorized that Venus formed out of ingredients similar to Earth’s, but followed a different evolutionary path. Measurements by NASA’s Pioneer mission to Venus in the 1980s first suggested Venus originally may have had an ocean. However, Venus is closer to the sun than Earth and receives far more sunlight. As a result, the planet’s early ocean evaporated, water-vapor molecules were broken apart by ultraviolet radiation, and hydrogen escaped to space. With no water left on the surface, carbon dioxide built up in the atmosphere, leading to a so-called runaway greenhouse effect that created present conditions.

Previous studies have shown that how fast a planet spins on its axis affects whether it has a habitable climate. A day on Venus is 117 Earth days. Until recently, it was assumed that a thick atmosphere like that of modern Venus was required for the planet to have today’s slow rotation rate. However, newer research has shown that a thin atmosphere like that of modern Earth could have produced the same result. That means an ancient Venus with an Earth-like atmosphere could have had the same rotation rate it has today.

Another factor that impacts a planet’s climate is topography. The GISS team postulated ancient Venus had more dry land overall than Earth, especially in the tropics. That limits the amount of water evaporated from the oceans and, as a result, the greenhouse effect by water vapor. This type of surface appears ideal for making a planet habitable; there seems to have been enough water to support abundant life, with sufficient land to reduce the planet’s sensitivity to changes from incoming sunlight.

Way and his GISS colleagues simulated conditions of a hypothetical early Venus with an atmosphere similar to Earth’s, a day as long as Venus’ current day, and a shallow ocean consistent with early data from the Pioneer spacecraft. The researchers added information about Venus’ topography from radar measurements taken by NASA’s Magellan mission in the 1990s, and filled the lowlands with water, leaving the highlands exposed as Venusian continents. The study also factored in an ancient sun that was up to 30 percent dimmer. Even so, ancient Venus still received about 40 percent more sunlight than Earth does today.

“In the GISS model’s simulation, Venus’ slow spin exposes its dayside to the sun for almost two months at a time,” co-author and fellow GISS scientist Anthony Del Genio said. “This warms the surface and produces rain that creates a thick layer of clouds, which acts like an umbrella to shield the surface from much of the solar heating. The result is mean climate temperatures that are actually a few degrees cooler than Earth’s today.”

The research was done as part of NASA’s Planetary Science Astrobiology program through the Nexus for Exoplanet System Science (NExSS) program, which seeks to accelerate the search for life on planets orbiting other stars, or exoplanets, by combining insights from the fields of astrophysics, planetary science, heliophysics, and Earth science. The findings have direct implications for future NASA missions, such as the Transiting Exoplanet Survey Satellite and James Webb Space Telescope, which will try to detect possible habitable planets and characterize their atmospheres.

Image Credit: NASA
Explanation from: https://www.nasa.gov/feature/goddard/2016/nasa-climate-modeling-suggests-venus-may-have-been-habitable

The Large Magellanic Cloud Galaxy in the Infrared

This image shows the Large Magellanic Cloud galaxy in infrared light as seen by the Herschel Space Observatory, a European Space Agency-led mission with important NASA contributions, and NASA's Spitzer Space Telescope. In the instruments' combined data, this nearby dwarf galaxy looks like a fiery, circular explosion. Rather than fire, however, those ribbons are actually giant ripples of dust spanning tens or hundreds of light-years. Significant fields of star formation are noticeable in the center, just left of center and at right. The brightest center-left region is called 30 Doradus, or the Tarantula Nebula, for its appearance in visible light.

The colors in this image indicate temperatures in the dust that permeates the Cloud. Colder regions show where star formation is at its earliest stages or is shut off, while warm expanses point to new stars heating surrounding dust. The coolest areas and objects appear in red, corresponding to infrared light taken up by Herschel's Spectral and Photometric Imaging Receiver at 250 microns, or millionths of a meter. Herschel's Photoconductor Array Camera and Spectrometer fills out the mid-temperature bands, shown here in green, at 100 and 160 microns. The warmest spots appear in blue, courtesy of 24- and 70-micron data from Spitzer.

Image Credit: ESA/NASA/JPL-Caltech/STScI
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA15254

Infrared view of the Rho Ophiuchi star-forming region

A rich collection of colorful astronomical objects is revealed in this picturesque image of the Rho Ophiuchi cloud complex from NASA's Wide-field Infrared Explorer, or WISE. The Rho Ophiuchi cloud (pronounced 'oh-fee-yoo-ki' and named after a bright star in the region) is found rising above the plane of the Milky Way in the night sky, bordering the constellations Ophiuchus and Scorpius. It's one of the nearest star-forming regions to Earth, allowing us to resolve much more detail than in more distant similar regions, like the Orion nebula.

The amazing variety of colors seen in this image represents different wavelengths of infrared light. The bright white nebula in the center of the image is glowing due to heating from nearby stars, resulting in what is called an emission nebula. The same is true for most of the multi-hued gas prevalent throughout the entire image, including the bluish, bow-shaped feature near the bottom right. The bright red area in the bottom right is light from the star in the center -- Sigma Scorpii -- that is reflected off of the dust surrounding it, creating what is called a reflection nebula. And the much darker areas scattered throughout the image are pockets of cool, dense gas that block out the background light, resulting in absorption (or 'dark') nebulae. WISE's longer wavelength detectors can typically see through dark nebulae, but these are exceptionally opaque.

The bright pink objects just left of center are young stellar objects (YSOs). These baby stars are just now forming; many of them are still enveloped in their own tiny compact nebulae. In visible light, these YSOs are completely hidden in the dark nebula that surrounds them, which is sometimes referred to as their baby blanket. We can also see some of the oldest stars in our Milky Way galaxy in this image, found in two separate (and much more distant) globular clusters. The first cluster, M80, is on the far right edge of the image towards the top. The second, NGC 6144, is found close to the bottom edge near the center. They both appear as small densely compacted groups of blue stars. Globular clusters such as these typically harbor some of the oldest stars known, some as old as 13 billion years, born soon after the universe formed.

There are two other items of interest in this image as well. At the 3 o'clock position, relative to the bright central region, and about two-thirds of the way from the center to the edge, there is a small faint red dot (more visible in the larger downloadable image files). That dot is an entire galaxy far far away known as PGC 090239. And, at the bottom left of the image, there are two lines emerging from the edge. These were not created by foreground satellites; they are diffraction spikes (optical artifacts from the space telescope) from the bright star Antares that is just out of the field of view.

The colors used in this image represent specific wavelengths of infrared light. Blue and cyan (blue-green) represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars. Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust.

Image Credit: NASA/JPL-Caltech/UCLA
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA13974

Artist's impression of the Gamma-Ray Burst 140903A

This artist's illustration depicts the aftermath of a neutron star merger, including the generation of a Gamma-ray burst (GRB). In the center is a compact object - either a black hole or a massive neutron star - and in red is a disk of material left over from the merger, containing material falling towards the compact object. Energy from this infalling material drives the GRB jet shown in yellow. In orange is a wind of particles blowing away from the disk and in blue is material ejected from the compact object and expanding at very high speeds of about one tenth the speed of light.

Image Credit: NASA/CXC/M.Weiss
Explanation from: http://chandra.harvard.edu/photo/2016/grb/more.html

Star Cluster NGC 2060

The star cluster NGC 2060 is a loose collection of stars that are no longer gravitationally bound to each other. The stellar grouping will disperse in a few million years. It contains a supernova that exploded about 10,000 years ago, blowing out gas surrounding it. The dark region below the cluster is a dense cloud of dust lying in front of it.

30 Doradus is the brightest, nearby star-forming region and home to the most massive stars in our cosmic neighborhood of about 25 galaxies. The nebula is close enough to Earth that Hubble can resolve individual stars, giving astronomers important information about the stars' birth and evolution. 30 Doradus resides 170,000 light-years away in the Large Magellanic Cloud, a small, satellite galaxy of our Milky Way.

Image Credit: NASA, ESA
Explanation from: http://hubblesite.org/newscenter/archive/releases/2012/01/image/e/

Artist’s impression of the exotic binary star system AR Scorpii

This artist’s impression shows the strange object AR Scorpii. In this unique double star a rapidly spinning white dwarf star (right) powers electrons up to almost the speed of light. These high energy particles release blasts of radiation that lash the companion red dwarf star (left) and cause the entire system to pulse dramatically every 1.97 minutes with radiation ranging from the ultraviolet to radio.

Image Credit: M. Garlick/ESA/Hubble
Explanation from: https://www.spacetelescope.org/images/heic1616a/

Pluto's Blue Atmosphere

Pluto's haze layer shows its blue color in this picture taken by the New Horizons Ralph/Multispectral Visible Imaging Camera (MVIC). The high-altitude haze is thought to be similar in nature to that seen at Saturn's moon Titan. The source of both hazes likely involves sunlight-initiated chemical reactions of nitrogen and methane, leading to relatively small, soot-like particles (called tholins) that grow as they settle toward the surface. This image was generated by software that combines information from blue, red and near-infrared images to replicate the color a human eye would perceive as closely as possible.

Image Credit: NASA
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA19964

Galaxy Cluster Abell S1063

The newest target of Hubble’s mission is the distant galaxy cluster Abell S1063, potentially home to billions of strange new worlds.

This view of the cluster, which can be seen in the centre of the image, shows it as it was four billion years ago. But Abell S1063 allows us to explore a time even earlier than this, where no telescope has really looked before. The huge mass of the cluster distorts and magnifies the light from galaxies that lie behind it due to an effect called gravitational lensing. This allows Hubble to see galaxies that would otherwise be too faint to observe and makes it possible to search for, and study, the very first generation of galaxies in the Universe. “Fascinating”, as a famous Vulcan might say.

The first results from the data on Abell S1063 promise some remarkable new discoveries. Already, a galaxy has been found that is observed as it was just a billion years after the Big Bang.

Astronomers have also identified sixteen background galaxies whose light has been distorted by the cluster, causing multiple images of them to appear on the sky. This will help astronomers to improve their models of the distribution of both ordinary and dark matter in the galaxy cluster, as it is the gravity from these that causes the distorting effects. These models are key to understanding the mysterious nature of dark matter.

Abell S1063 is not alone in its ability to bend light from background galaxies, nor is it the only one of these huge cosmic lenses to be studied using Hubble. Three other clusters have already been observed as part of the Frontier Fields programme, and two more will be observed over the next few years, giving astronomers a remarkable picture of how they work and what lies both within and beyond them.

Data gathered from the previous galaxy clusters were studied by teams all over the world, enabling them to make important discoveries, among them galaxies that existed only hundreds of million years after the Big Bang and the first predicted appearance of a gravitationally lensed supernova.

Such an extensive international collaboration would have made Gene Roddenberry, the father of Star Trek, proud. In the fictional world Roddenberry created, a diverse crew work together to peacefully explore the Universe. This dream is partially achieved by the Hubble programme in which the European Space Agency (ESA), supported by 22 member states, and NASA collaborate to operate one of the most sophisticated scientific instruments in the world. Not to mention the scores of other international science teams that cross state, country and continental borders to achieve their scientific aims.

Image Credit: NASA, ESA, and J. Lotz (STScI)
Explanation from: https://www.spacetelescope.org/news/heic1615/

Artist's impression of planets transiting red dwarf star in TRAPPIST-1 system

This artist's impression shows two Earth-sized worlds passing in front of their parent red dwarf star, which is much smaller and cooler than our Sun. The star and its orbiting planets TRAPPIST-1b and TRAPPIST-1c reside 40 light-years away. The planets are between 20 and 100 times closer to their star than Earth is to the Sun. Researchers think that at least one of the planets, and possibly both, may be within the star's habitable zone, where moderate temperatures could allow for liquid water on the surface. Hubble looked for evidence of extended atmospheres around both planets and didn't find anything.

Image Credit: NASA, ESA, and G. Bacon (STScI)
Explanation from: https://www.spacetelescope.org/images/opo1627a/

Moon seen from the International Space Station

Backdropped by Earth's horizon and the blackness of space, a full moon is photographed by an Expedition 29 crew member on the International Space Station.

Image Credit: NASA

New research reveals Fluctuating Atmosphere of Jupiter’s volcanic moon Io

Jupiter’s volcanic moon Io has a thin atmosphere that collapses in the shadow of Jupiter, condensing as ice, according to a new study by NASA-funded researchers. The study reveals the freezing effects of Jupiter’s shadow during daily eclipses on the moon’s volcanic gases.

“This research is the first time scientists have observed this remarkable phenomenon directly, improving our understanding of this geologically active moon,” said Constantine Tsang, a scientist at the Southwest Research Institute in Boulder, Colorado. The study was published Aug. 2 in the Journal of Geophysical Research.

Io is the most volcanically active object in the solar system. The volcanoes are caused by tidal heating, the result of gravitational forces from Jupiter and other moons. These forces result in geological activity, most notably volcanoes that emit umbrella-like plumes of sulfur dioxide gas that can extend up to 300 miles (480 kilometers) above Io and produce extensive basaltic lava fields that can flow for hundreds of miles.

The new study documents atmospheric changes on Io as the giant planet casts its shadow over the moon’s surface during daily eclipses. Io’s thin atmosphere, which consists primarily of sulfur dioxide (SO2) gas emitted from volcanoes, collapses as the SO2 freezes onto the surface as ice when Io is shaded by Jupiter, then is restored when the ice warms and sublimes (i.e. transforms from solid back to gas) when the moon moves out of eclipse back into sunlight.

The study used the large eight-meter Gemini North telescope in Hawaii and an instrument called the Texas Echelon Cross Echelle Spectrograph (TEXES). Data showed that Io’s atmosphere begins to “deflate” when the temperatures drop from -235 degrees Fahrenheit in sunlight to -270 degrees Fahrenheit during eclipse. Eclipse occurs two hours of every Io day (1.7 Earth days). In full eclipse, the atmosphere effectively collapses, as most of the sulfur dioxide gas settles as frost on the moon’s surface. The atmosphere redevelops as the surface warms once the moon returns to full sunlight.

“This confirms that Io’s atmosphere is in a constant state of collapse and repair, and shows that a large fraction of the atmosphere is supported by sublimation of SO2 ice,” said John Spencer, a co-author of the new study, also at the Southwest Research Institute. “Though Io’s hyperactive volcanoes are the ultimate source of the SO2, sunlight controls the atmospheric pressure on a daily basis by controlling the temperature of the ice on the surface. We’ve long suspected this, but can finally watch it happen.”

Prior to the study, no direct observations of Io’s atmosphere in eclipse had been possible because Io’s atmosphere is difficult to observe in the darkness of Jupiter’s shadow. This breakthrough was possible because TEXES measures the atmosphere using heat radiation, not sunlight, and the giant Gemini telescope can sense the faint heat signature of Io’s collapsing atmosphere.

The observations occurred over two nights in November 2013, when Io was more than 420 million miles (675 million kilometers) from Earth. On both occasions, Io was observed moving into Jupiter’s shadow for a period about 40 minutes before and after the start of the eclipse.

Image Credit: SwRI/Andrew Blanchard
Explanation from: https://www.nasa.gov/feature/new-research-reveals-fluctuating-atmosphere-of-jupiter-s-volcanic-moon

Star-Formation Region in Perseus

A low activity, star-formation region in the constellation Perseus, as seen by Planck. This long-wavelength image covers a square region of 13 by 13 degrees (which is equivalent 26 by 26 full moons). It is a three-color combination constructed from three of Planck's nine frequency channels: 30, 353 and 857 gigahertz.

Image Credit: ESA/LFI & HFI Consortia
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA13065

Lake Balkhash seen from the International Space Station

This stunning Earth image taken by the Expedition 47 crew on May 31, 2016, from the International Space Station looks from northwestern China on the bottom into eastern Kazakhstan. The large lake in Kazakhstan with golden sun glint is the crescent-shaped Lake Balkhash, the second largest lake in Central Asia. Lake Balkhash sits in the Balkhash-Alakol depression in southeastern Kazakhstan and stretches over 7,115 square miles (18,428 sq. km).

Image Credit: NASA
Explanation from: http://www.nasa.gov/image-feature/beams-of-light-on-a-golden-lake

Astronomers help focus research in the search for another Earth

Using public data collected by NASA's Kepler mission, astronomers have catalogued the planet candidates that may be similar to our third rock from the Sun. The tabulation of candidates will help astronomers focus their research efforts in the search for life.

The analysis, led by Stephen Kane, an associate professor of physics and astronomy at San Francisco State University in California, highlights 20 candidates in the Kepler trove that are less than twice the size of Earth and orbit their star in the conservative habitable zone—the range of distances where liquid water could pool on the surface of an orbiting planet. Of these 20 candidates, nine have been previously investigated and determined to be verified planets, including notables like Kepler-62f, Kepler-186f, Kepler-283c, Kepler-296f and Kepler-442b.

Image Credit: Danielle Futselaar
Explanation from: https://exoplanets.nasa.gov/news/1379/astronomers-help-focus-research-in-the-search-for-another-earth/

Pluto

Four images from NASA's New Horizons' Long Range Reconnaissance Imager (LORRI) were combined with color data from the Ralph instrument to create this global view of Pluto. (The lower right edge of Pluto in this view currently lacks high-resolution color coverage.) The images, taken when the spacecraft was 280,000 miles (450,000 kilometers) away, show features as small as 1.4 miles (2.2 kilometers), twice the resolution of the single-image view taken on July 13, 2015.

Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA19857

SOHO sees Bright Sungrazer Comet

ESA and NASA’s Solar and Heliospheric Observatory, or SOHO, saw a bright comet plunge toward the Sun on August 3-4, 2016, at nearly 1.3 million miles per hour. Comets are chunks of ice and dust that orbit the Sun, usually on highly elliptical orbits that carry them far beyond the orbit of Pluto at their farthest points. This comet, first spotted by SOHO on August 1, is part of the Kreutz family of comets, a group of comets with related orbits that broke off of a huge comet several centuries ago.

This comet didn’t fall into the Sun, but rather whipped around it – or at least, it would have if it had survived its journey. Like most sungrazing comets, this comet was torn apart and vaporized by the intense forces near the Sun.

The disk of the Sun is represented by the white circle in this image.

Image Credit: ESA/NASA/SOHO/Joy Ng
Explanation from: https://www.nasa.gov/image-feature/goddard/2016/esa-nasa-s-soho-sees-bright-sungrazer-comet