NASA Astronomy Picture of the Day:

The world is waking up to a picturesque planet parade. Just before dawn, the eastern skies over much of planet Earth are decorated by a notable line of familiar planets. In much of Earth's northern hemisphere, this line of planets appears most nearly horizontal, but in much of Earth's southern hemisphere, the line appears more nearly vertical. Pictured over the Sydney Opera House in southern Australia, the planet line was captured nearly vertical about five days ago. From top to bottom, the morning planets are Saturn, Mars, Venus, and Jupiter. As April ends, the angular distance between Venus and Jupiter will gradually pass below a degree as they switch places. Then, as May ends, Jupiter will pass near Mars as those two planets switch places. In June, the parade will briefly expand to include Mercury. Notable Submissions to APOD: Morning Planet Parade 2022

Photo by Prasun Agrawal

NASA Astronomy Picture of the Day:

In one of the brightest parts of Milky Way lies a nebula where some of the oddest things occur. NGC 3372, known as the Great Nebula in Carina, is home to massive stars and changing nebulas. The Keyhole Nebula (NGC 3324), the bright structure just below the image center, houses several of these massive stars. The entire Carina Nebula, captured here, spans over 300 light years and lies about 7,500 light-years away in the constellation of Carina. Eta Carinae, the most energetic star in the nebula, was one of the brightest stars in the sky in the 1830s, but then faded dramatically. While Eta Carinae itself maybe on the verge of a supernova explosion, X-ray images indicate that much of the Great Nebula in Carina has been a veritable supernova factory.

Photo by Ignacio Javier Diaz Bobillo

NASA Astronomy Picture of the Day:

Just now, before you hit the button, two future universes are possible. After pressing the button, though, you will live in only one. A real-web version of the famous Schrödinger's cat experiment clicking the red button in the featured astronaut image should transform that image into a picture of the same astronaut holding one of two cats -- one living, or one dead. The timing of your click, combined with the wiring of your brain and the millisecond timing of your device, will all conspire together to create a result dominated, potentially, by the randomness of quantum mechanics. Some believe that your personally-initiated quantum decision will split the universe in two, and that both the live-cat and dead-cat universes exist in separate parts of a larger multiverse. Others believe that the result of your click will collapse the two possible universes into one -- in a way that could not have been predicted beforehand. Yet others believe that the universe is classically deterministic, so that by pressing the button you did not really split the universe, but just carried out an action predestined since time began. We at APOD believe that however silly you may feel clicking the red button, and regardless of the outcome, you should have a thought-provoking day. Or two.

NASA Astronomy Picture of the Day:

A gorgeous spiral galaxy, Messier 104 is famous for its nearly edge-on profile featuring a broad ring of obscuring dust lanes. Seen in silhouette against an extensive central bulge of stars, the swath of cosmic dust lends a broad brimmed hat-like appearance to the galaxy suggesting a more popular moniker, the Sombrero Galaxy. This sharp view of the well-known galaxy was made from over 10 hours of Hubble Space Telescope image data, processed to bring out faint details often lost in the overwhelming glare of M104's bright central bulge. Also known as NGC 4594, the Sombrero galaxy can be seen across the spectrum, and is host to a central supermassive black hole. About 50,000 light-years across and 28 million light-years away, M104 is one of the largest galaxies at the southern edge of the Virgo Galaxy Cluster. Still, the spiky foreground stars in this field of view lie well within our own Milky Way.

NASA Astronomy Picture of the Day:

No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. Instead, the shadow line or terminator is diffuse and shows the gradual transition to darkness we experience as twilight. With the Sun illuminating the scene from the right, the cloud tops reflect gently reddened sunlight filtered through the dusty troposphere, the lowest layer of the planet's nurturing atmosphere. A clear high altitude layer, visible along the dayside's upper edge, scatters blue sunlight and fades into the blackness of space. This picture was taken in June of 2001 from the International Space Station orbiting at an altitude of 211 nautical miles. Of course from home, you can check out the Earth Now. Celebrate: Today is Earth Day

NASA Astronomy Picture of the Day:

Fifty years ago, April 20, 1972, Apollo 16's lunar module Orion touched down on the Moon's near side in the south-central Descartes Highlands. While astronaut Ken Mattingly orbited overhead in Casper the friendly command and service module the Orion brought John Young and Charles Duke to the lunar surface. The pair would spend nearly three days on the Moon. Constructed from images (AS16-117-18814 to AS16-117-18820) taken near the end of their third and final surface excursion this panoramic view puts the lunar module in the distance toward the left. Their electric lunar roving vehicle in the foreground, Duke is operating the camera while Young aims the high gain communications antenna skyward, toward planet Earth. Celebrate: Earth Day

NASA Astronomy Picture of the Day:

There's an interesting sky to see if you wake up before the Sun. Lined up on toward the eastern horizon are four planets in a row. The planets are so bright they can even be seen from the bright sky inside a city. In fact, the featured image was taken from New York City, USA, with the foreground highlighted by the RFK (Triborough) Bridge. Pictured, the planets are, left to right, Jupiter, Venus, Mars, and Saturn. The planets all appear in a row because they all orbit the Sun in the same plane. This plane, called the ecliptic plane, was created in the early days of our Solar System and includes all planets, including Earth. The morning planet parade will continue throughout April and May, and will even be joined by Mercury in June. APOD volunteer programming opportunity: Discord

Photo by Stan Honda

NASA Astronomy Picture of the Day:

The eggs from this gigantic chicken may form into stars. The featured emission nebula, shown in scientifically assigned colors, is cataloged as IC 2944 but known as the Running Chicken Nebula for the shape of its greater appearance. Seen toward the bottom of the image are small, dark molecular clouds rich in obscuring cosmic dust. Called Thackeray's Globules for their discoverer, these "eggs" are potential sites for the gravitational condensation of new stars, although their fates are uncertain as they are also being rapidly eroded away by the intense radiation from nearby young stars. Together with patchy glowing gas and complex regions of reflecting dust, these massive and energetic stars form the open cluster Collinder 249. This gorgeous skyscape spans about 60 light-years at the nebula's estimated 6,500 light-year distance.

Photo by Stefan Steve Bemmerl

NASA Astronomy Picture of the Day:

The mission was to document night-flying birds -- but it ended up also documenting a beautiful sky. The featured wide-angle mosaic was taken over the steppe golden fields in Mértola, Portugal in 2020. From such a dark location, an immediately-evident breathtaking glow arched over the night sky: the central band of our Milky Way galaxy. But this sky had much more. Thin clouds crossed the sky like golden ribbons. The planet Mars appeared on the far left, while the planets Saturn and Jupiter were also simultaneously visible -- but on the opposite side of the sky, here seen on the far right. Near the top of the image the bright star Vega can be found, while the far-distant and faint Andromeda Galaxy can be seen toward the left, just below Milky Way's arch. As the current month progresses, several planets are lining up in the pre-dawn sky: Jupiter, Venus, Mars, and Saturn. Did you know? Many APODs have links for adventure & humor

Photo by Miguel ClaroTWAN

NASA Astronomy Picture of the Day:

What's that approaching? Astronauts on board the International Space Station in 2010 first saw it far in the distance. Soon it enlarged to become a dark silhouette. As it came even closer, the silhouette appeared to be a spaceship. Finally, the object revealed itself to be the Space Shuttle Endeavour, and it soon docked as expected with the Earth-orbiting space station. Pictured here, Endeavour was imaged near Earth's horizon as it approached, where several layers of the Earth's atmosphere were visible. Directly behind the shuttle is the mesosphere, which appears blue. The atmospheric layer that appears white is the stratosphere, while the orange layer is Earth's Troposphere. Together, these thin layers of air -- collectively spanning less than 2 percent of Earth's radius -- sustain us all in many ways, including providing oxygen to breath and a barrier to dangerous radiations from space. Coming up Friday: Earth Day 2022

NASA Astronomy Picture of the Day:

Taken with a camera fixed to a tripod, many short exposures were aligned with the stars to unveil this beautiful, dark night sky. Captured near the rural village of Albany`a at the northeastern corner of Spain, the three stars of Orion's belt stretch across top center in the starry frame. Alnitak, the easternmost (left) of the belt stars is seen next to the more diffuse glow of the Flame Nebula and the dark notch of the famous Horsehead. Easily visible to the naked-eye The Great Nebula of Orion is below the belt stars. A mere 1,500 light-years distant, it is the closest large stellar nursery to our fair planet. Best seen in photographs, the broad and faint arc of Barnard's Loop seems to embrace Orion's brighter stars and nebulae though. In the northern spring the familiar northern winter constellation is setting. Near the western horizon toward lower right Orion's apparently bright blue supergiant Rigel just touches the branches of a pine tree.

Photo by Juan Carlos Casado

NASA Astronomy Picture of the Day:

Wind-sharpened rocks known as ventifacts, cover this broad sloping plain in the foot hills of Mount Sharp, Gale crater, Mars. Dubbed gator-back rocks their rugged, scaly appearance is captured in these digitally stitched Mastcam frames from the Curiosity rover on mission sol 3,415 (March 15, 2022). Driving over gator-back rocks before has resulted in damage to the rover's wheels, so Curiosity team members decided to turn around and take another path to continue the rover's climb. Curiosity has been on an ascent of Gale crater's central 5.5 kilometer high mountain since 2014. As it climbs, it's been able to study layers shaped by water on Mars billions of years ago.