Aurora over Icelandic Fault Aurora over Icelandic Fault

Admire the beauty but fear the beast. The beauty is the aurora overhead, here taking the form of great green spiral, seen between picturesque clouds with the bright Moon to the side and stars in the background. The beast is the wave of charged particles that creates the aurora but might, one day, impair civilization. Exactly this week in 1859, following notable auroras seen all across the globe, a pulse of charged particles from a coronal mass ejection (CME) associated with a solar flare impacted Earth's magnetosphere so forcefully that they created the Carrington Event. A relatively direct path between the Sun and the Earth might have been cleared by a preceding CME. What is sure is that the Carrington Event compressed the Earth's magnetic field so violently that currents were created in telegraph wires so great that many wires sparked and gave telegraph operators shocks. Were a Carrington-class event to impact the Earth today, speculation holds that damage might occur to global power grids and electronics on a scale never yet experienced. The featured aurora was imaged last week over Thingvallavatn Lake in Iceland, a lake that partly fills a fault that divides Earth's large Eurasian and North American tectonic plates. via NASA http://ift.tt/2byz7QQ

Abell 370: Galaxy Cluster Gravitational Lens Abell 370: Galaxy Cluster Gravitational Lens

What is that strange arc? While imaging the cluster of galaxies Abell 370, astronomers had noted an unusual arc to the right of many cluster galaxies. Although curious, one initial response was to avoid commenting on the arc because nothing like it had ever been noted before. In the mid-1980s, however, better images allowed astronomers to identify the arc as a prototype of a new kind of astrophysical phenomenon -- the gravitational lens effect of entire cluster of galaxies on background galaxies. Today, we know that this arc actually consists of two distorted images of a fairly normal galaxy that happened to lie far behind the huge cluster. Abell 370's gravity caused the background galaxies' light -- and others -- to spread out and come to the observer along multiple paths, not unlike a distant light appears through the stem of a wine glass. In mid-July of 2009, astronomers used the then just-upgraded Hubble Space Telescope to image Abell 370 and its gravitational lens images in unprecedented detail. Almost all of the yellow images featured here are galaxies in the Abell 370 cluster. An astute eye can pick up many strange arcs and distorted arclets, however, that are actually images of more distant galaxies. Studying Abell 370 and its images gives astronomers a unique window into the distribution of normal and dark matter in galaxy clusters and the universe. via NASA http://ift.tt/2bXXoiK

Lunar Orbiter Earthset Lunar Orbiter Earthset

August 10th was the 50th anniversary of the launch of Lunar Orbiter 1. It was the first of five Lunar Orbiters intended to photograph the Moon's surface to aid in the selection of future landing sites. That spacecraft's camera captured the data used in this restored, high-resolution version of its historic first image of Earth from the Moon on August 23, 1966 while on its 16th lunar orbit. Hanging almost stationary in the sky when viewed from the lunar surface, Earth appears to be setting beyond the rugged lunar horizon from the perspective of the orbiting spacecraft. Two years later, the Apollo 8 crew would record a more famous scene in color: Earthrise from lunar orbit. via NASA http://ift.tt/2chQLuW

Closest Star has Potentially Habitable Planet Closest Star has Potentially Habitable Planet

The star closest to the Sun has a planet similar to the Earth. As announced yesterday, recent observations confirmed that this planet not only exists but inhabits a zone where its surface temperature could allow liquid water, a key ingredient for life on Earth. It is not yet known if this planet, Proxima b, has any life. Even if not, its potential ability to sustain liquid water might make it a good first hop for humanity's future trips out into the Milky Way Galaxy. Although the planet's parent star, Proxima Centauri, is cooler and redder than our Sun, one of the other two stars in the Alpha Centauri star system is very similar to our Sun. The featured image shows the sky location of Proxima Centauri in southern skies behind the telescope that made many of the discovery observations: ESO's 3.6-meter telescope in La Silla, Chile. The discovered planet orbits close in -- so close one year there takes only 11 days on Earth. The planet was discovered by the ESO's Pale Red Dot collaboration. Although seemingly unlikely, if Proxima b does have intelligent life, at 4.25 light years distance it is close enough to Earth for two-way communication. via NASA http://ift.tt/2carMtC

Curiosity at Murray Buttes on Mars Curiosity at Murray Buttes on Mars

What are these unusual lumps on Mars? As NASA's robotic Curiosity rover continues rolling across Mars, it is now approaching Murray Buttes. Several of the 15-meter high buttes are visible ahead in this horizontally compressed 360-degree across image taken inside Gale Crater earlier this month. The buttes are thought similar to Earth buttes in that they are capped with dense rock that is relatively resistant to erosion. In the image center is Curiosity's "arm" and "hand" used to examine rocks up close, drill into rocks, and collect samples. Curiosity has reached its four year anniversary on Mars and has been cleared to spend the next two years further exploring the slopes of Mount Sharp, the peak of which is the distant light-colored structure visible on the far left. via NASA http://ift.tt/2bglGC5

Tutulemma: Solar Eclipse Analemma Tutulemma: Solar Eclipse Analemma

If you went outside at exactly the same time every day and took a picture that included the Sun, how would the Sun's position change? With great planning and effort, such a series of images can be taken. The figure-8 path the Sun follows over the course of a year is called an analemma. At the Winter Solstice in Earth's northern hemisphere, the Sun appears at the bottom of the analemma. Analemmas created from different latitudes appear at least slightly different, as well as analemmas created at a different time each day. With even greater planning and effort, the series can include a total eclipse of the Sun as one of the images. Pictured is such a total solar eclipse analemma or Tutulemma - a term coined by the photographers based on the Turkish word for eclipse. The featured composite image sequence was recorded from Turkey starting in 2005. The base image for the sequence is from the total phase of a solar eclipse as viewed from Side, Turkey on 2006 March 29. Venus was also visible during totality, toward the lower right. If you want to create your own USA-based tutulemma ending at next August's total solar eclipse, now would be good time to start. via NASA http://ift.tt/2bwzRrA

Map of Total Solar Eclipse Path in 2017 August Map of Total Solar Eclipse Path in 2017 August

Would you like to see a total eclipse of the Sun? If so, do any friends or relatives live near the path of next summer's eclipse? If yes again, then you might want to arrange a visit for one year from today. Next year on this exact date, the path of a total solar eclipse will cut right across the center of the contiguous USA. All of North America and part of South America will experience, at the least, a partial solar eclipse. Featured here is a map of the path of totality, computed by eclipse expert Fred Espenak of NASA's GSFC. Many people who have seen a total solar eclipse tell stories about it for the rest of their lives. The last path of solar totality that included any part of the contiguous USA was in 1979, and the next two will be in 2024 and 2044. via NASA http://ift.tt/2bdhxQS

Perseid Fireball at Sunset Crater Perseid Fireball at Sunset Crater

On the night of August 12, this bright Perseid meteor flashed above volcanic Sunset Crater National Monument, Arizona, USA, planet Earth. Streaking along the summer Milky Way, its initial color is likely due to the shower meteor's characteristically high speed. Entering at 60 kilometers per second, Perseid meteors are capable of exciting green emission from oxygen atoms while passing through the tenuous atmosphere at high altitudes. Also characteristic of bright meteors, this Perseid left a visibly glowing persistent train. Its evolution is seen over a three minute sequence (left to right) spanning the bottom of the frame. The camera ultimately captured a dramatic timelapse video of the twisting, drifting train. via NASA http://ift.tt/2byQIpz

Five Planets and the Moon over Australia Five Planets and the Moon over Australia

It is not a coincidence that planets line up. That's because all of the planets orbit the Sun in (nearly) a single sheet called the plane of the ecliptic. When viewed from inside that plane -- as Earth dwellers are likely to do -- the planets all appear confined to a single band. It is a coincidence, though, when several of the brightest planets all appear in nearly the same direction. Such a coincidence was captured just last week. Featured above, six planets and Earth's Moon were all imaged together last week, just before sunset, from Mornington Peninsula in Victoria, Australia. A second band is visible across the top of this tall image -- the central band of our Milky Way Galaxy. via NASA http://ift.tt/2bClNx6

Human as Spaceship Human as Spaceship

You are a spaceship soaring through the universe. So is your dog. We all carry with us trillions of microorganisms as we go through life. These multitudes of bacteria, fungi, and archaea have different DNA than you. Collectively called your microbiome, your shipmates outnumber your own cells. Your crew members form communities, help digest food, engage in battles against intruders, and sometimes commute on a liquid superhighway from one end of your body to the other. Much of what your microbiome does, however, remains unknown. You are the captain, but being nice to your crew may allow you to explore more of your local cosmos. via NASA http://ift.tt/2aW739w

The Keyhole in the Carina Nebula The Keyhole in the Carina Nebula

The dark dusty Keyhole Nebula gets its name from its unusual shape. The looping Keyhole, in this featured classic image by the Hubble Space Telescope, is a smaller region inside the larger Carina Nebula. Dramatic dark dust knots and complex features are sculpted by the winds and radiation of the Carina Nebula's many massive and energetic stars. In particular, the shape of the dust cloud on the upper left of the Keyhole Nebula may stimulate the human imagination to appear similar to, for example, a superhero flying through a cloud, arm up, with a saved person in tow below. The region lies about 7,500 light-years away in planet Earth's southern sky. The Keyhole Nebula was created by the dying star Eta Carina , out of the frame, which is prone to violent outbursts during its final centuries. via NASA http://ift.tt/2b78zFw

The Easterbunny Comes to NGC 4725 The Easterbunny Comes to NGC 4725

At first called "Easterbunny" by its discovery team, officially named Makemake is the second brightest dwarf planet of the Kuiper belt. The icy world appears twice in this astronomical image, based on data taken on June 29 and 30 of the bright spiral galaxy NGC 4725. Makemake is marked by short red lines, its position shifting across a homemade telescope's field-of-view over two nights along a distant orbit. On those dates nearly coincident with the line-of-sight to the spiral galaxy in the constellation Coma Berenices, Makemake was about 52.5 astronomical units or 7.3 light-hours away. NGC 4725 is over 100,000 light-years across and 41 million light-years distant. Makemake is now known to have at least one moon. NGC 4725 is a famous one-armed spiral galaxy. via NASA http://ift.tt/2bnxiZk

Colliding Galaxies in Stephans Quintet Colliding Galaxies in Stephans Quintet

Will either of these galaxies survive? In what might be dubbed as a semi-final round in a galactic elimination tournament, the two spirals of NGC 7318 are colliding. The featured picture was created from images taken by the Hubble Space Telescope. When galaxies crash into each other, many things may happen including gravitational distortion, gas condensing to produce new episodes of star formation, and ultimately the two galaxies combining into one. Since these two galaxies are part of Stephan's Quintet, a final round of battling galaxies will likely occur over the next few billion years with the eventual result of many scattered stars and one large galaxy. Quite possibly, the remaining galaxy will not be easily identified with any of its initial galactic components. Stephan's Quintet was the first identified galaxy group, lies about 300 million light years away, and is visible through a moderately-sized telescope toward the constellation of the Winged Horse (Pegasus). via NASA http://ift.tt/2bfKPSy

Perseid Meteors over Mount Shasta Perseid Meteors over Mount Shasta

Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Perseus. That is why the meteor shower that peaks later this week is known as the Perseids -- the meteors all appear to came from a radiant toward Perseus. In terms of parent body, though, the sand-sized debris that makes up the Perseids meteors come from Comet Swift-Tuttle. The comet follows a well-defined orbit around our Sun, and the part of the orbit that approaches Earth is superposed in front of the Perseus. Therefore, when Earth crosses this orbit, the radiant point of falling debris appears in Perseus. Featured here, a composite image containing over 60 meteors from last August's Perseids meteor shower shows many bright meteors that streaked over Mount Shasta, California, USA. This year's Perseids holds promise to be the best meteor shower of the year. via NASA http://ift.tt/2aV4SkG

Io: Moon over Jupiter Io: Moon over Jupiter

How big is Jupiter's moon Io? The most volcanic body in the Solar System, Io (usually pronounced "EYE-oh") is 3,600 kilometers in diameter, about the size of planet Earth's single large natural satellite. Gliding past Jupiter at the turn of the millennium, the Cassini spacecraft captured this awe inspiring view of active Io with the largest gas giant as a backdrop, offering a stunning demonstration of the ruling planet's relative size. Although in the featured picture Io appears to be located just in front of the swirling Jovian clouds, Io hurtles around its orbit once every 42 hours at a distance of 420,000 kilometers or so from the center of Jupiter. That puts Io nearly 350,000 kilometers above Jupiter's cloud tops, roughly equivalent to the distance between Earth and Moon. In July, NASA's Juno satellite began orbiting Jupiter and will sometimes swoop to within 5,000 kilometers of Jupiter's cloud tops. via NASA http://ift.tt/2aEpBhA

Las Campanas Moon and Mercury Las Campanas Moon and Mercury

Last Thursday the view toward sunset from the 2.5 kilometer summit of Cerro Las Campanas in the remote Chilean Andes was amazing. Bright but fading Mercury stood very close to a two day old Moon. Both a sunlit lunar crescent and earthlit lunar nightside are captured with the fleeting innermost planet in this breathtaking mountainscape. Even below the conjunction of Moon and Mercury, a close pairing of brilliant Venus and bright star Regulus hangs in the sky, still above the colorful western horizon. Of course amazing skies above Las Campanas are not unexpected. The region is currently home to the twin Magellan telescopes of the Las Campanas Observatory and the summit location is the site of the future Giant Magellan Telescope. via NASA http://ift.tt/2b1a5vU

M63: Sunflower Galaxy Wide Field M63: Sunflower Galaxy Wide Field

The Sunflower Galaxy blooms near the center of this wide field telescopic view. The scene spans about 2 degrees or 4 full moons on the sky toward the loyal constellation Canes Venatici. More formally known as Messier 63, the majestic island universe is nearly 100,000 light-years across, about the size of our own Milky Way Galaxy. Surrounding its bright yellowish core, sweeping spiral arms are streaked with cosmic dust lanes and dotted with star forming regions. A dominant member of a known galaxy group, M63 has faint, extended features that could be the the remains of dwarf satellite galaxies, evidence that large galaxies grow by accreting small ones. M63 shines across the electromagnetic spectrum and is thought to have undergone bursts of intense star formation. via NASA http://ift.tt/2akDW0Y

Behold the Universe Behold the Universe

What if you climbed up on a rock and discovered the Universe? You can. Although others have noted much of it before, you can locate for yourself stars, planets, and even the plane of our Milky Way Galaxy. All you need is a dark clear sky -- the rock is optional. If you have a camera, you can further image faint nebulas, galaxies, and long filaments of interstellar dust. If you can process digital images, you can bring out faint features, highlight specific colors, and merge foreground and background images. In fact, an industrious astrophotographer has done all of these to create the presented picture. All of the component images were taken early last month on the same night within a few meters of each other. The picturesque setting was Sand Beach in Stonington, Maine, USA with the camera pointed south over Penobscot Bay. via NASA http://ift.tt/2aPLnOx