July 15, 2017

Lightning Eclipse from the Planet of the Goats

Thunderstorms almost spoiled this view of the spectacular 2011 June 15 total lunar eclipse. Instead, storm clouds parted for 10 minutes during the total eclipse phase and lightning bolts contributed to the dramatic sky. Captured with a 30-second exposure the scene also inspired one of the more memorable titles (thanks to the astrophotographer) in APOD's now 22-year history. Of course, the lightning reference clearly makes sense, and the shadow play of the dark lunar eclipse was widely viewed across planet Earth in Europe, Africa, Asia, and Australia. The picture itself, however, was shot from the Greek island of Ikaria at Pezi. That area is known as "the planet of the goats" because of the rough terrain and strange looking rocks. via NASA http://ift.tt/2vnh0Eo

July 14, 2017

Close up of the Great Red Spot

On July 11, the Juno spacecraft once again swung near to Jupiter's turbulent cloud tops in its looping 53 day orbit around the Solar System's ruling gas giant. About 11 minutes after perijove 7, its closest approach on this orbit, it passed directly above Jupiter's Great Red Spot. During the much anticipated fly over, it captured this close-up image data from a distance of less than 10,000 kilometers. The raw JunoCam data was subsequently processed by citizen scientists. Very long-lived but found to be shrinking, the Solar System's largest storm system was measure to be 16,350 kilometers wide on April 15. That's about 1.3 times the diameter of planet Earth. via NASA http://ift.tt/2tljAtd

July 13, 2017

NGC 4449: Close up of a Small Galaxy

(xxxedit and linkxxx) Grand spiral galaxies often seem to get all the glory. Their young, blue star clusters and pink star forming regions along sweeping spiral arms are guaranteed to attract attention. But small irregular galaxies form stars too, like NGC 4449, about 12 million light-years distant. Less than 20,000 light-years across, the small island universe is similar in size, and often compared to our Milky Way's satellite galaxy, the Large Magellanic Cloud (LMC). This remarkable Hubble Space Telescope close-up of the well-studied galaxy was reprocessed to highlight the telltale reddish glow of hydrogen gas. The glow traces NGC 4449's widespread star forming regions, some even larger than those in the LMC, with enormous interstellar arcs and bubbles blown by short-lived, massive stars. NGC 4449 is a member of a group of galaxies found in the constellation Canes Venatici. It also holds the distinction of being the first dwarf galaxy with an identified tidal star stream. via NASA http://ift.tt/2ugs7Sm

July 12, 2017

Full Moon and Boston Light

This well-planned telephoto timelapse captures July's Full Moon rise across outer Boston Harbor, Massachusetts, planet Earth. In the foreground, the historic terrestrial beacon is known as Boston Light. July's Full Moon is known to some as a Thunder Moon, likely a reference to the sounds of the northern summer month's typically stormy weather. But the eastern sky was clear for this video sequence. Near the horizon, the long sight-line through atmospheric layers filters and refracts the moonlight, causing the rising Moon's reddened color, ragged edges and distorted shape. via NASA http://ift.tt/2t2FdmP

July 11, 2017

Messier 63: The Sunflower Galaxy

A bright spiral galaxy of the northern sky, Messier 63 is about 25 million light-years distant in the loyal constellation Canes Venatici. Also cataloged as NGC 5055, the majestic island universe is nearly 100,000 light-years across. That's about the size of our own Milky Way Galaxy. Known by the popular moniker, The Sunflower Galaxy, M63 sports a bright yellowish core in this sharp composite image from space- and ground-based telescopes. Its sweeping blue spiral arms are streaked with cosmic dust lanes and dotted with pink star forming regions. A dominant member of a known galaxy group, M63 has faint, extended features that are likely star streams from tidally disrupted satellite galaxies. M63 shines across the electromagnetic spectrum and is thought to have undergone bursts of intense star formation. via NASA http://ift.tt/2v5Wecs

July 10, 2017

Star Cluster Omega Centauri in HDR

Behold the largest ball of stars in our galaxy. Omega Centauri is packed with about 10 million stars, many older than our Sun and packed within a volume of only about 150 light-years in diameter. The star cluster is the largest and brightest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. Though most star clusters consist of stars with the same age and composition, the enigmatic Omega Cen exhibits the presence of different stellar populations with a spread of ages and chemical abundances. In fact, Omega Cen may be the remnant core of a small galaxy merging with the Milky Way. The featured image shows so many stars because it merged different exposures with high dynamic range (HDR) techniques. Omega Centauri, also known as NGC 5139, lies about 15,000 light-years away toward the southern constellation of the Centaurus. via NASA http://ift.tt/2tFFKIl

July 9, 2017

Spiral Galaxy NGC 1512: The Nuclear Ring

What's happening around the center of this spiral galaxy? Seen in total, NGC 1512 appears to be a barred spiral galaxy -- a type of spiral that has a straight bar of stars across its center. This bar crosses an outer ring, though, a ring not seen as it surrounds the pictured region. Featured in this Hubble Space Telescope image is an inner ring -- one that itself surrounds the nucleus of the spiral. The two rings are connected not only by a bar of bright stars but by dark lanes of dust. Inside of this inner ring, dust continues to spiral right into the very center -- possibly the location of a large black hole. The rings are bright with newly formed stars which may have been triggered by the collision of NGC 1512 with its galactic neighbor, NGC 1510. via NASA http://ift.tt/2tVECTF

July 7, 2017

Hidden Galaxy IC 342

Similar in size to large, bright spiral galaxies in our neighborhood, IC 342 is a mere 10 million light-years distant in the long-necked, northern constellation Camelopardalis. A sprawling island universe, IC 342 would otherwise be a prominent galaxy in our night sky, but it is hidden from clear view and only glimpsed through the veil of stars, gas and dust clouds along the plane of our own Milky Way galaxy. Even though IC 342's light is dimmed by intervening cosmic clouds, this sharp telescopic image traces the galaxy's own obscuring dust, blue star clusters, and glowing pink star forming regions along spiral arms that wind far from the galaxy's core. IC 342 may have undergone a recent burst of star formation activity and is close enough to have gravitationally influenced the evolution of the local group of galaxies and the Milky Way. via NASA http://ift.tt/2uwQnx4

July 6, 2017

A View Toward M106

Big, bright, beautiful spiral, Messier 106 dominates this cosmic vista. The two degree wide telescopic field of view looks toward the well-trained constellation Canes Venatici, near the handle of the Big Dipper. Also known as NGC 4258, M106 is about 80,000 light-years across and 23.5 million light-years away, the largest member of the Canes II galaxy group. For a far away galaxy, the distance to M106 is well-known in part because it can be directly measured by tracking this galaxy's remarkable maser, or microwave laser emission. Very rare but naturally occuring, the maser emission is produced by water molecules in molecular clouds orbiting its active galactic nucleus. Another prominent spiral galaxy on the scene, viewed nearly edge-on, is NGC 4217 below and right of M106. The distance to NGC 4217 is much less well-known, estimated to be about 60 million light-years. via NASA http://ift.tt/2tKWlNp

July 5, 2017

Atlas, Daphnis, and Pan

Atlas, Daphnis, and Pan are small, inner, ring moons of Saturn, shown at the same scale in this montage of images from the still Saturn-orbiting Cassini spacecraft. In fact, Daphnis was discovered in Cassini images from 2005. Atlas and Pan were first sighted in images from the Voyager 1 and 2 spacecraft. Flying saucer-shaped Atlas orbits near the outer edge of Saturn's bright A Ring while Daphnis orbits inside the A Ring's narrow Keeler Gap and Pan within the A Ring's larger Encke Gap. The curious equatorial ridges of the small ring moons could be built up by the accumulation of ring material over time. Even diminutive Daphnis makes waves in the ring material as it glides along the edge of the Keeler Gap.

July 4, 2017

Aphelion Sunrise

On July 3rd, planet Earth reached aphelion, the farthest point in its elliptical orbit around the Sun. Each year, this day of the most distant Sun happens to occur during winter in the southern hemisphere. That's where this aphelion sunrise from 2015 was captured in a time series composite against the skyline of Brisbane, Australia. Of course, seasons for our fair planet are not determined by distance to the Sun, but by the tilt of Earth's rotational axis with respect to the ecliptic, the plane of its orbit. Fondly known as the obliquity of the ecliptic, the angle of the tilt is about 23.4 degrees from perpendicular to the orbital plane. So the most distant sunrise occurs during northern summer, when the planet's north pole is tilted toward the Sun and the north enjoys longer, warmer days. via NASA http://ift.tt/2ulvNQp

July 2, 2017

The Summer Triangle over the Great Wall

Have you ever seen the Summer Triangle? The bright stars Vega, Deneb, and Altair form a large triangle on the sky that can be seen rising in the northern spring during the morning, and rising in the northern fall during the evening. During summer months, the triangle can be found nearly overhead near midnight as three of the brightest stars on the sky. Featured here, along with the arch of the central band of our Milky Way Galaxy, the Summer Triangle asterism was captured this spring over the Great Wall of China. This part of the Great Wall, a World Culture Heritage Site, was built during the 6th century on the Yan Mountains. At the summit is Wangjinglou Tower from which, on a clear night, the lights of Beijing are visible in the distance. via NASA http://ift.tt/2udOcP0

July 1, 2017

Mountains of Dust in the Carina Nebula

It's stars versus dust in the Carina Nebula and the stars are winning. More precisely, the energetic light and winds from massive newly formed stars are evaporating and dispersing the dusty stellar nurseries in which they formed. Located in the Carina Nebula and known informally as Mystic Mountain, these pillar's appearance is dominated by the dark dust even though it is composed mostly of clear hydrogen gas. Dust pillars such as these are actually much thinner than air and only appear as mountains due to relatively small amounts of opaque interstellar dust. About 7,500 light-years distant, the featured image was taken with the Hubble Space Telescope and highlights an interior region of Carina which spans about three light years. Within a few million years, the stars will likely win out completely and the entire dust mountain will evaporate. via NASA http://ift.tt/2uvhGqS