Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 April 20

Planet Line over New York Bridge

Image Credit & Copyright: Stan Honda

Explanation: 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

Discover the cosmos!

Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 April 19

Stars and Globules in the Running Chicken Nebula

Image Credit & Copyright: Stefan Steve Bemmerl

Explanation: 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.

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 April 18

Stars and Planets over Portugal

Image Credit & Copyright: Miguel Claro (TWAN, Dark Sky Alqueva)

Explanation: 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.

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Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 April 17

Shuttle Over Earth

Image Credit: NASA, Expedition 22 Crew

Explanation: 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.

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 April 16

Orion Pines

Image Credit & Copyright: Juan Carlos Casado (Starry Earth, TWAN)

Explanation: 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.

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 April 15

The Gator-back Rocks of Mars

Image Credit: NASA, JPL-Caltech, MSSS

Explanation: 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.