Sharp telescopic views of NGC 3628 show a puffy galactic disk divided by dark dust lanes. Of course, this deep portrait of the magnificent, edge-on spiral galaxy puts some astronomers in mind of its popular moniker, the Hamburger Galaxy. It also reveals a small galaxy nearby, likely a satellite of NGC 3628, and a faint but extensive tidal tail. The tantalizing island universe itself is about 100,000 light-years across and 35 million light-years away in the northern springtime constellation Leo. Its drawn out tail stretches for about 300,000 light-years, even beyond the left edge of the wide frame. NGC 3628 shares its neighborhood in the local Universe with two other large spirals M65 and M66 in a grouping otherwise known as the Leo Triplet. Gravitational interactions with its cosmic neighbors are likely responsible for creating the tidal tail, as well as the extended flare and warp of this spiral's disk.

What has the Curiosity rover come across on Mars? Dubbed Mount Remarkable, the rolling robot has chanced upon this notable 5-meter tall mound during its continuing journey around and, eventually, up 5.5-kilometer high Mt. Sharp. Unsure of the density of the surrounding layered sandstone, the human team on Earth has instructed the car-sized rover on Mars to drill into a rock on the side of Mt. Remarkable to investigate. Quite possibly, water involved in creating the dense sandstone could have helped to support ancient life on the red planet. Mt. Sharp, the unusual central peak of Gale Crater, has a similar base-to-peak height as Earth's Mt. Everest.

Our Sun has become quite a busy place. Taken only two weeks ago, the Sun was captured sporting numerous tumultuous regions including active sunspot regions AR 2036 near the image top and AR 2038 near the center. Only four years ago the Sun was emerging from an unusually quiet Solar Minimum that had lasted for years. The above image was recorded in a single color of light called Hydrogen Alpha, inverted, and false colored. Spicules cover much of the Sun's face like a carpet. The gradual brightening towards the Sun's edges is caused by increased absorption of relatively cool solar gas and called limb darkening. Just over the Sun's edges, several filamentary prominences protrude, while prominences on the Sun's face are seen as light streaks. Possibly the most visually interesting of all are the magnetically tangled active regions containing relatively cool sunspots, seen as white dots. Currently at Solar Maximum -- the most active phase in its 11-year magnetic cycle, the Sun's twisted magnetic field is creating numerous solar "sparks" which include eruptive solar prominences, coronal mass ejections, and flares which emit clouds of particles that may impact the Earth and cause auroras. One flare two years ago released such a torrent of charged particles into the Solar System that it might have disrupted satellites and compromised power grids had it struck planet Earth. News: Free APOD Lecture in Paris on June 17

How do you calibrate a huge gravitational lens? In this case the lens is the galaxy cluster Abell 383, a massive conglomeration of galaxies, hot gas, and dark matter that lies about 2.5 billion light years away (redshift z=0.187). What needs calibrating is the mass of the cluster, in particular the amount and distribution of dark matter. A new calibration technique has been tested recently that consists of waiting for supernovas of a very specific type to occur behind a galaxy cluster, and then figuring out how much the cluster must have magnified these supernovas through gravitational lensing. This technique complements other measures including computing the dark matter needed to contain internal galaxy motions, to confine cluster hot gas, and to create the gravitational lens image distortions. Pictured above from the Hubble Space Telescope, galaxy cluster A383 shows its gravitational lens capabilities on the right by highly distorting background galaxies behind the cluster center. On the left is a distant galaxy shown both before and after a recent revealing supernova. To date, calibration-quality supernovas of Type Ia have been found behind two other galaxy clusters by the Cluster Lensing And Supernova survey with Hubble (CLASH) project. Follow APOD on: Facebook, Google Plus, or Twitter

If Scorpius looked this good to the unaided eye, humans might remember it better. Scorpius more typically appears as a few bright stars in a well-known but rarely pointed out zodiacal constellation. To get a spectacular image like this, though, one needs a good camera, color filters, and a digital image processor. To bring out detail, the above image not only involved long duration exposures taken in several colors, but one exposure in a very specific red color emitted by hydrogen. The resulting image shows many breathtaking features. Vertically across the image left is part of the plane of our Milky Way Galaxy. Visible there are vast clouds of bright stars and long filaments of dark dust. Jutting out diagonally from the Milky Way in the image center are dark dust bands known as the Dark River. This river connects to several bright stars on the right that are part of Scorpius' head and claws, and include the bright star Antares. Above and right of Antares is an even brighter planet Jupiter. Numerous red emission nebulas and blue reflection nebulas are visible throughout the image. Scorpius appears prominently in southern skies after sunset during the middle of the year. Astrophysicists: Preview changes coming to the Astrophysics Source Code Library

The yellowish star near center in this dusty telescopic skyview is T Tauri, prototype of the class of T Tauri variable stars. Just next door is the yellow cosmic cloud historically known as Hind's Variable Nebula (NGC 1555). Over 400 light-years away, at the edge of an otherwise invisible molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing region. T Tauri stars are now generally recognized as young (less than a few million years old), sun-like stars still in the early stages of formation. To further complicate the picture, infrared observations indicate that T Tauri itself is part of a multiple system and suggest that the associated Hind's Nebula may also contain a very young stellar object. The naturally colored image spans about 7 light-years at the estimated distance of T Tauri.

Captured one night last May this eight frame mosaic starts on the left, down Northside Drive through Yosemite National Park. It ends thousands of light-years away though, as the arc of the Milky Way tracks toward the center of our galaxy on the right, far beyond the park's rugged skyline. That night was still moonless when the storm clouds retreated, so the rocky faces of the surrounding mountains are lit by campfires and artificial lights. Yosemite Falls is at the left. The granite face of Half Dome juts above the far horizon, near the center of the view. The remarkable flash above it is a bright meteor. Part of the annual Eta Aquarid meteor shower the colorful streak is moving up, its trail pointing directly back to the shower's radiant, low in Aquarius. This year's Eta Aquarids should peak in the moonless early morning hours of May 6 as the Earth sweeps through dust from the tail of Comet Halley.

In skies over Brisbane at the southeastern corner of Queensland, Australia, Planet Earth, the Sun and New Moon set together on April 29. There the celestial line-up, the first solar eclipse of 2014, was seen as a partial solar eclipse. This dramatic composite is a digital stack of images taken about 5 minutes apart with telephoto lens and solar filter. It follows the eclipse in progress, approaching a western horizon where crepuscular rays from cloud banks in silhouette joined the silhouetted Moon. From Brisbane, the maximum eclipse phase with the Moon covering about 25% of the Sun occurred just after sunset. Only from a remote spot on the continent of Antarctica was it even possible to see the eclipse in its brief annular phase, the entire dark lunar disk surrounded by a thin, bright ring of fire.

If you look closely, you will see something quite unusual about this setting Sun. There are birds flying to the Sun's left, but that's not so unusual. A dark sea covers the Sun's bottom, and dark clouds cover parts of the middle, but they are also not very unusual. More unusual is the occulted piece at the top right. And that's no occulting cloud -- that's the Moon. Yesterday the Moon moved in front of part of the Sun as visible from Australia, and although many locations reported annoying clouds, a partially eclipsed Sun would occasionally peek through as it set. The above image was captured yesterday on the western horizon of Adelaide, South Australia. The maximum eclipse was visible only from a small part of Antarctica where the entire Moon could be seen covering the entire center of the Sun in what is known as an annular eclipse, leaving only a ring of fire from the Sun peeking out around the edges. The next solar eclipse will be another partial eclipse, will occur on 2014 October 23, and will be visible from most of North America near sunset. Gallery: Yesterday's Solar Eclipse

Sometimes it is hard to believe what you see in the sky. While leading his annual aurora tour last month near Fairbanks in central Alaska, astrophotographer John Chumack and his company saw a most unusual aurora. This bright aurora appeared to change into the shape of a jumping dog, complete with a curly tail. He was able to capture the fleeting natural apparition in the above image with a 15-second exposure through a wide-angle lens. By coincidence, he also captured a background sky filled with familiar highlights. Planets visible include bright Jupiter through the dog's front legs and reddish Mars below the dog's hind legs. Stars visible include the Big Dipper stars above the dog's midsection and reddish Betelgeuse shining on the far right. This dog would not be following him home, however, and within a few minutes morphed into other shapes before the geomagnetic storm particles that created it shifted to strike the Earth elsewhere.

A spacesuit floated away from the International Space Station eight years ago, but no investigation was conducted. Everyone knew that it was pushed by the space station crew. Dubbed Suitsat-1, the unneeded Russian Orlan spacesuit filled mostly with old clothes was fitted with a faint radio transmitter and released to orbit the Earth. The suit circled the Earth twice before its radio signal became unexpectedly weak. Suitsat-1 continued to orbit every 90 minutes until it burned up in the Earth's atmosphere after a few weeks. Pictured above, the lifeless spacesuit was photographed in 2006 just as it drifted away from space station. Follow APOD on: Facebook, Google Plus, or Twitter

It's eclipse season, and on April 29 around 06:00 UT the shadow of the new Moon will reach out and touch planet Earth, though only just. Still, if you're standing on the continent of Antarctica within a few hundred kilometers of 79 degrees 38.7 minutes South latitude and 131 degrees 15.6 minutes East longitude you could see an annular solar eclipse with the Sun just above the horizon. Because the Moon will be approaching apogee, the most distant point in the elliptical lunar orbit, its apparent size will be too small to completely cover the solar disk. A rare, off-center eclipse, the annular phase will last at most 49 seconds. At its maximum it could look something like this "ring of fire" image from last May's annular solar eclipse, captured by a webcast team operating near Coen, Australia. Otherwise, a partial eclipse with the Moon covering at least some part of the Sun will be seen across a much broader region in the southern hemipshere, including Australia in the afternoon.