Earth, Lightning Storm, Airglow and Galactic Center of the Milky Way Galaxy seen from the International Space Station

Astronauts aboard the International Space Station (ISS) see the world at night on every orbit — that’s 16 times each crew day. An astronaut took this broad, short-lens photograph of Earth’s night lights while looking out over the remote reaches of the central equatorial Pacific Ocean. ISS was passing over the island nation of Kiribati at the time, about 2600 kilometers (1,600 miles) south of Hawaii.

Knowing the exact time and the location of the ISS, scientists were able to match the star field in the photo to charts describing which stars should have been visible at that moment. They identified the pattern of stars in the photo as our Milky Way galaxy (looking toward its center). The dark patches are dense dust clouds in an inner spiral arm of our galaxy; such clouds can block our view of stars toward the center.

The curvature of the Earth crosses the center of the image and is illuminated by a variety of airglow layers in orange, green, and red. Setting stars are visible even through the dense orange-green airglow.

The brightest light in the image is a lightning flash that illuminated a large mass of clouds. The flash reflected off the shiny solar arrays of the ISS and back to the camera. The dim equatorial cloud sheet is so extensive that it covers most of the sea surface in this view.

ISS, Orbit of the Earth

August 9, 2015

Image Credit: NASA
Explanation from: http://www.nasa.gov/image-feature/stargazing-from-the-international-space-station

Alpha Camelopardalis

NASA's Wide-field Infrared Survey Explorer, or WISE, captured this image of the star Alpha Camelopardalis, or Alpha Cam in astronomer-speak, speeding through the sky like a motorcyclist zipping through rush-hour traffic. The supergiant star Alpha Cam is the bright star in the middle of this image, surrounded on one side by an arc-shaped cloud of dust and gas, colored red in this infrared view.

Such fast-moving stars are called runaway stars. The distance and speed of Alpha Cam is somewhat uncertain. It is probably somewhere between 1,600 and 6,900 light-years away and moving at an astonishing rate of somewhere between 680 and 4,200 kilometers per second (between 1.5 and 9.4 million miles per hour). It turns out that WISE is particularly adept at imaging bow shocks from runaway stars. Previous examples can be seen around Zeta Ophiuchi, AE Aurigae, and Menkhib. But Alpha Cam revs things up into a different gear. To put its speed into perspective, if Alpha Cam were a car driving across the United States at 4,200 kilometers per second, it would take less than one second to travel from San Francisco to New York City!

Astronomers believe runaway stars are set into motion either through the supernova explosion of a companion star or through gravitational interactions with other stars in a cluster. Because Alpha Cam is a supergiant star, it gives off a very strong wind. The speed of the wind is boosted in the forward direction the star is moving in space. When this fast-moving wind slams into the slower-moving interstellar material, a bow shock is created, similar to the wake in front of the bow of a ship in water. The stellar wind compresses the interstellar gas and dust, causing it to heat up and glow in infrared. Alpha Cam's bow shock cannot be seen in visible light, but WISE's infrared detectors show us the graceful arc of heated gas and dust around the star.

The red arc of Alpha Cam adds to collection of colorful objects in WISE images taken of the constellation Camelopardalis, or the Giraffe. The gaudily clad giraffe has what looks like a ruby choker above an emerald necklace just to the southeast, as well as an ankle bracelet.

The colors used in this image represent specific wavelengths of infrared light. Stars are seen primarily in blue and cyan (blue-green), because they are emitting light brightly at 3.4 and 4.6 microns. Green represents 12-micron light, primarily emitted by dust. The red of the blow shock represents light emitted at 22 microns.

Image Credit: NASA/JPL-Caltech/UCLA
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA13908

Open Star Cluster IC 1590

Astronomers have used the NASA/ESA Hubble Space Telescope to study the young open star cluster IC 1590, which is found within the star formation region NGC 281 — nicknamed the Pacman Nebula due to its resemblance to the famous arcade game character. This image only shows the central part of the nebula, where the brightest stars at the core of the cluster are found, with part of the Pacman’s hungry mouth visible as the dark region below.

But Pacman isn’t gobbling up these stars. Instead, the nebula’s gas and dust are being used as raw ingredients to make new stars. However, the stars in IC 1590 are still plotting their escape from the Pacman Nebula, as open clusters are only loosely bound together and the grouping will eventually disperse within a few tens of millions of years.

IC 1590 lies about ten thousand light-years from Earth in the constellation of Cassiopeia (The Queen). Through small telescopes the core of the cluster that appears at the top of this picture shows up as a triple star, but the nebula that surrounds it is much fainter and very hard to see. The eagle-eyed American astronomer E. E. Barnard, using a 15 cm telescope, first recorded it in the late nineteenth century.

This picture was created from images taken using the Wide Field Channel of Hubble’s Advanced Camera for Surveys. Images though yellow (F550M, coloured blue), orange (F660N, coloured green) and red (F658N) filters were combined. The F658N filter isolates light from glowing hydrogen gas. The total exposure times per filter were 450 s, 1017 s and 678 s, respectively and the field of view is about 3.3 arcminutes across.

Image Credit: ESA/Hubble & NASA
Explanation from: https://www.spacetelescope.org/images/potw1115a/

The NGC 253 Galaxy

NGC 253, also known as the Sculptor Galaxy, is the brightest of the Sculptor Group of galaxies, found in the constellation of the same name, and lying approximately 13 million light-years from Earth. The Sculptor Galaxy is known as a starburst galaxy for its current high rate of star formation, one result of which is its superwind, a stream energetic material spewing out from the centre of the galaxy out into space. The purple light comes from that frenzy of star formation, which originally began 30 million years ago, while the yellowish colour is created by dust lit up by young, massive stars.

This image combines observations performed through three different filters (B, V, R) with the 1.5-metre Danish telescope at the ESO La Silla Observatory in Chile.

Image Credit: ESO/IDA/Danish 1.5 m/ R. Gendler, U. G. Jørgensen, J. Skottfelt, K. Harpsøe
Explanation from: http://www.eso.org/public/images/potw1017a/

LL Ori and the Orion Nebula

This esthetic close-up of cosmic clouds and stellar winds features LL Orionis, interacting with the Orion Nebula flow. Adrift in Orion's stellar nursery and still in its formative years, variable star LL Orionis produces a wind more energetic than the wind from our own middle-aged Sun. As the fast stellar wind runs into slow moving gas a shock front is formed, analogous to the bow wave of a boat moving through water or a plane traveling at supersonic speed.

The small, arcing, graceful structure just above and left of center is LL Ori's cosmic bow shock, measuring about half a light-year across. The slower gas is flowing away from the Orion Nebula's hot central star cluster, the Trapezium, located off the upper left corner of the picture. In three dimensions, LL Ori's wrap-around shock front is shaped like a bowl that appears brightest when viewed along the "bottom" edge. The beautiful picture is part of a large mosaic view of the complex stellar nursery in Orion, filled with a myriad of fluid shapes associated with star formation.

Image Credit: NASA, ESA and the Hubble Heritage Team
Explanation from: https://www.nasa.gov/multimedia/imagegallery/image_feature_2442.html

The Rho Ophiuchi star-forming region

This wide-field view shows the star-forming region Rho Ophiuchi in the constellation of Ophiuchus (The Serpent Bearer), as seen in visible light. This view was created from images forming part of the Digitized Sky Survey 2.

Image Credit: ESO/Digitized Sky Survey 2, Davide De Martin

Tornado near Campo in Colorado

Campo, Colorado, USA

Image Credit: Jason Persoff Stormdo/Getty Images/Cultura RM

Star Cluster NGC 2040

These bright stars shining through what looks like a haze in the night sky are part of a young stellar grouping in one of the largest known star formation regions of the Large Magellanic Cloud (LMC), a dwarf satellite galaxy of the Milky Way. The image was captured by the NASA/ESA Hubble Space Telescope’s Wide Field Planetary Camera 2.

The stellar grouping is known to stargazers as NGC 2040 or LH 88. It is essentially a very loose star cluster whose stars have a common origin and are drifting together through space. There are three different types of stellar associations defined by their stellar properties. NGC 2040 is an OB association, a grouping that usually contains 10–100 stars of type O and B — these are high-mass stars that have short but brilliant lives. It is thought that most of the stars in the Milky Way were born in OB associations.

There are several such groupings of stars in the LMC. Just like the others, LH 88 consists of several high-mass young stars in a large nebula of partially ionised hydrogen gas, and lies in what is known to be a supergiant shell of gas called LMC 4.

Over a period of several million years, thousands of stars may form in these supergiant shells, which are the largest interstellar structures in galaxies. The shells themselves are believed to have been created by strong stellar winds and clustered supernova explosions of massive stars that blow away surrounding dust and gas, and in turn trigger further episodes of star formation.

The LMC is the third closest galaxy to our Milky Way. It is located some 160 000 light-years away, and is about 100 times smaller than our own.

This image, which shows ultraviolet, visible and infrared light, covers a field of view of approximately 1.8 by 1.8 arcminutes.

Image Credit: ESA/Hubble, NASA and D. A Gouliermis, Eedresha Sturdivant
Explanation from: https://www.spacetelescope.org/images/potw1216a/

Spiral Galaxy Messier 96

This NASA/ESA Hubble Space Telescope shows Messier 96, a spiral galaxy just over 35 million light-years away in the constellation of Leo (The Lion). It is of about the same mass and size as the Milky Way. It was first discovered by astronomer Pierre Méchain in 1781, and added to Charles Messier’s famous catalogue of astronomical objects just four days later.

The galaxy resembles a giant maelstrom of glowing gas, rippled with dark dust that swirls inwards towards the nucleus. Messier 96 is a very asymmetric galaxy; its dust and gas is unevenly spread throughout its weak spiral arms, and its core is not exactly at the galactic centre. Its arms are also asymmetrical, thought to have been influenced by the gravitational pull of other galaxies within the same group as Messier 96.

This group, named the M96 Group, also includes the bright galaxies Messier 105 and Messier 95, as well as a number of smaller and fainter galaxies. It is the nearest group containing both bright spirals and a bright elliptical galaxy (Messier 105).

Image Credit: ESA/Hubble & NASA and the LEGUS Team, R. Gendler
Explanation from: https://www.spacetelescope.org/images/potw1535a/

Sakurajima Volcano Eruption

Kagoshima Prefecture, Japan

February 5, 2016

Image Credit: Kyodo

Star-forming region NGC 346

NGC 346, the brightest star-forming region in the neighbouring Small Magellanic Cloud galaxy, some 210,000 light-years away from Earth. The light, wind and heat given off by massive stars have dispersed the glowing gas within and around this star cluster, forming a surrounding wispy nebular structure that looks like a cobweb. NGC 346 is located in the constellation Tucana (the Toucan) and spans approximately 200 light-years. This particular image was obtained using the Wide Field Imager instrument at the 2.2-metre MPG/ESO telescope at the La Silla Observatory in Chile. Images like this help astronomers chronicle star birth and evolution, while offering glimpses of how stellar development influences the appearance of the cosmic environment over time. This is an enhanced colour image based on three different broadband filters (B, V, R), as well as a narrowband filter (H-alpha, shown in blue). The field of view is about 30 arcminutes wide.

Image Credit: ESO
Explanation from: https://www.eso.org/public/images/eso1008a/

The star cluster Messier 47

This spectacular image of the star cluster Messier 47 was taken using the Wide Field Imager camera, installed on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. This young open cluster is dominated by a sprinkling of brilliant blue stars but also contains a few contrasting red giant stars.

Image Credit: ESO

Double rainbow, Supercell and Tornado in Colorado

Simla, Colorado, USA

June 4, 2015

Image Credit & Copyright: Kelly DeLay

Wide-field view of the sky around the exotic binary star system AR Scorpii

This wide-field image from the Digitized Sky Survey 2 shows the rich starfields surrounding the exotic binary star system AR Scorpii.

Image Credit: Digitized Sky Survey 2, Davide De Martin

The Loneliest Young Star

This artist’s concept shows an unusual celestial object called CX330 was first detected as a source of X-ray light in 2009 by NASA’s Chandra X-Ray Observatory while it was surveying the bulge in the central region of the Milky Way. A 2016 study in the Monthly Notices of the Royal Astronomical Society found that CX330 is the most isolated young star that has been discovered. Researchers compared NASA’s Wide-field Infrared Survey Explorer (WISE) data from 2010 with NASA’s Spitzer Space Telescope data from 2007 to come to this conclusion.

CX330 is not near any star-forming region. As of the most recent observation, which was August 2015, this object was outbursting, meaning it was launching “jets” of material that slam into the gas and dust around it. Astronomers plan to continue studying the object, including with future telescopes that could view CX330 in other wavelengths of light.

Image Credit: NASA/JPL-Caltech
Explanation from: http://www.nasa.gov/image-feature/jpl/pia20700/the-loneliest-young-star

Supernova Remnant DEM L316A

This NASA/ESA Hubble Space Telescope image captures the remnants of a long-dead star. These rippling wisps of ionised gas, named DEM L316A, are located some 160 000 light-years away within one of the Milky Way’s closest galactic neighbours — the Large Magellanic Cloud (LMC).

The explosion that formed DEM L316A was an example of an especially energetic and bright variety of supernova, known as a Type Ia. Such supernova events are thought to occur when a white dwarf star steals more material than it can handle from a nearby companion, and becomes unbalanced. The result is a spectacular release of energy in the form of a bright, violent explosion, which ejects the star’s outer layers into the surrounding space at immense speeds. As this expelled gas travels through the interstellar material, it heats it up and ionise it, producing the faint glow that Hubble’s Wide Field Camera 3 has captured here.

The LMC orbits the Milky Way as a satellite galaxy and is the fourth largest in our group of galaxies, the Local Group. DEM L316A is not alone in the LMC; Hubble came across another one in 2010 with SNR 0509, and in 2013 it snapped SNR 0519.

Image Credit: ESA/Hubble & NASA, Y. Chu
Explanation from: https://www.spacetelescope.org/images/potw1630a/

Pluto’s moon Charon

NASA’s New Horizons spacecraft has returned the best color and the highest resolution images yet of Pluto’s largest moon, Charon – and these pictures show a surprisingly complex and violent history.

At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system. Many New Horizons scientists expected Charon to be a monotonous, crater-battered world; instead, they’re finding a landscape covered with mountains, canyons, landslides, surface-color variations and more.

“We thought the probability of seeing such interesting features on this satellite of a world at the far edge of our solar system was low,” said Ross Beyer, an affiliate of the New Horizons Geology, Geophysics and Imaging (GGI) team from the SETI Institute and NASA Ames Research Center in Mountain View, California, “but I couldn't be more delighted with what we see."

High-resolution images of the Pluto-facing hemisphere of Charon, taken by New Horizons as the spacecraft sped through the Pluto system on July 14 and transmitted to Earth on Sept. 21, reveal details of a belt of fractures and canyons just north of the moon’s equator. This great canyon system stretches more than 1,000 miles (1,600 kilometers) across the entire face of Charon and likely around onto Charon’s far side. Four times as long as the Grand Canyon, and twice as deep in places, these faults and canyons indicate a titanic geological upheaval in Charon’s past.

“It looks like the entire crust of Charon has been split open,” said John Spencer, deputy lead for GGI at the Southwest Research Institute in Boulder, Colorado. “With respect to its size relative to Charon, this feature is much like the vast Valles Marineris canyon system on Mars.”

The team has also discovered that the plains south of the Charon’s canyon -- informally referred to as Vulcan Planum -- have fewer large craters than the regions to the north, indicating that they are noticeably younger. The smoothness of the plains, as well as their grooves and faint ridges, are clear signs of wide-scale resurfacing.

One possibility for the smooth surface is a kind of cold volcanic activity, called cryovolcanism. “The team is discussing the possibility that an internal water ocean could have frozen long ago, and the resulting volume change could have led to Charon cracking open, allowing water-based lavas to reach the surface at that time,” said Paul Schenk, a New Horizons team member from the Lunar and Planetary Institute in Houston.

Even higher-resolution Charon images and composition data are still to come as New Horizons transmits data, stored on its digital recorders, over the next year – and as that happens, “I predict Charon’s story will become even more amazing!” said mission Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

The New Horizons spacecraft is currently 3.1 billion miles (5 billion kilometers) from Earth, with all systems healthy and operating normally.

New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. APL designed, built, and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning.

Image Credit: NASA/JHUAPL/SwRI
Explanation from: http://www.nasa.gov/feature/pluto-s-big-moon-charon-reveals-a-colorful-and-violent-history

Moonset seen from the International Space Station

Expedition 47 Flight Engineer Tim Peake of the European Space Agency took this striking photograph of the moon from his vantage point aboard the International Space Station on March 28, 2016.

Image Credit: ESA/NASA

Star Cluster Hodge 301

The star cluster Hodge 301 is 20 million to 25 million years old. Hodge 301 is home to many aging, red supergiant stars, indicating the cluster is older. Roughly 40 massive stars already have exploded as supernovas. The expanding wave of debris is slamming into gas ejected by stars in R136, creating a ridge of star formation between the two clusters. The fledgling stars are embedded in dense gas and cannot be seen.

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/d/

The Kiso 5639 Galaxy

In this NASA Hubble Space Telescope image, a firestorm of star birth is lighting up one end of the diminutive galaxy Kiso 5639. The dwarf galaxy is shaped like a flattened pancake, but because it is tilted edge-on, it resembles a skyrocket, with a brilliant blazing head and a long, star-studded tail.

Kiso 5639 is a member of a class of galaxies called "tadpoles" because of their bright heads and elongated tails. This galaxy resides relatively nearby, at 82 million light-years away. Tadpoles are rare in the local universe but more common in the distant cosmos, suggesting that many galaxies pass through a phase like this as they evolve.

Hubble observations of Kiso 5639 have uncovered the stellar content and bright pink glow of hydrogen at one end of the galaxy. A burst of new stars in a region measuring 2,700 light-years across makes the hydrogen clouds glow. The mass of these young stars equals about 1 million suns. The stars are grouped into large clusters that formed less than 1 million years ago.

Stars consist mainly of hydrogen and helium, but cook up other "heavier" elements, such as oxygen and carbon. When the stars die, they release their heavy elements and enrich the surrounding gas. In Kiso 5639, the bright gas in the galaxy's head is more deficient in heavy elements than the rest of the galaxy. Astronomers, therefore, think that this new star-formation event was triggered when the galaxy accreted primordial gas from its surroundings, since intergalactic space contains more pristine, hydrogen-rich gas.

The elongated tail, seen stretching away from the galaxy's head and scattered with bright blue stars, contains at least four distinct star-forming regions. These stars appear to be older than those in the star-forming head.

Hubble also revealed giant holes peppered throughout the starburst end. These cavities give this area a Swiss-cheese appearance because numerous supernova detonations — like firework aerial bursts — have carved out holes of rarified superheated gas. Wispy filaments, comprising gas and some stars, extend away from the main body of the cosmic tadpole.

The observations were taken in February 2015 and July 2015 with Hubble's Wide Field Camera 3.

Image Credit: NASA, ESA
Explanation from: http://hubblesite.org/newscenter/archive/releases/2016/23/image/a/

Supermassive Black Holes

The blue dots in this field of galaxies, known as the COSMOS field, show galaxies that contain supermassive black holes emitting high-energy X-rays. The black holes were detected by NASA's Nuclear Spectroscopic Array, or NuSTAR, which spotted 32 such black holes in this field and has observed hundreds across the whole sky so far.

The other colored dots are galaxies that host black holes emitting lower-energy X-rays, and were spotted by NASA's Chandra X-ray Observatory. Chandra data show X-rays with energies between 0.5 to 7 kiloelectron volts, while NuSTAR data show X-rays between 8 to 24 kiloelectron volts.

Image Credit: NASA/JPL-Caltech
Explanation from: http://www.nasa.gov/image-feature/jpl/pia20865/a-black-hole-choir