In this evocative night scene a dusty central Milky Way rises over the ancient Andean archaeological site of Yacoraite in northwestern Argentina. The denizens of planet Earth reaching skyward are the large Argentine saguaro cactus currently native to the arid region. The unusual yellow-hued reflection nebula above is created by dust scattering starlight around red giant star Antares. Alpha star of the constellation Scorpius, Antares is over 500 light-years distant. Next to it bright blue Rho Ophiuchi is embedded in more typical dusty bluish reflection nebulae though. The deep night skyscape was created from a series of background exposures of the rising stars made while tracking the sky, and a foreground exposure of the landscape made with the camera and lens fixed on the tripod. In combination they produce the single stunning image and reveal a range of brightness and color that your eye can't quite perceive on its own.


This detailed image features Abell 3827, a galaxy cluster that offers a wealth of exciting possibilities for study.

This detailed image features Abell 3827, a galaxy cluster that offers a wealth of exciting possibilities for study. Hubble observed it in order to study dark matter, which is one of the greatest puzzles cosmologists face today. The science team used Hubble’s Advanced Camera for Surveys and Wide Field Camera 3 to complete their observations. The two cameras have different specifications and can observe different parts of the electromagnetic spectrum, so using them both allowed the astronomers to collect more complete information. Hubble also observed Abell 3827 previously because of the interesting gravitational lens at its core. 

Looking at this cluster of hundreds of galaxies, it is amazing to recall that less than 100 years ago, many astronomers thought the Milky Way was the only galaxy in the universe. Although astronomers debated the existence of other galaxies, it took Edwin Hubble’s observations of the Great Andromeda Nebula to confirm that it was in fact far too distant to be part of the Milky Way. The Great Andromeda Nebula became the Andromeda Galaxy, and astronomers recognized that our universe was much, much bigger than humanity had envisioned. We can only imagine how Edwin Hubble – after whom the Hubble Space Telescope is named – would have felt if he’d seen this spectacular image of Abell 3827.

Text credit: European Space Agency (ESA)
Image credit: ESA/Hubble & NASA, R. Massey


Source: www.nasa.gov

Sixty years ago, near the dawn of the space age, NASA controllers "lit the candle" and sent Mercury astronaut Alan Shepard arcing into space atop a Redstone rocket. His cramped space capsule was dubbed Freedom 7. Broadcast live to a global television audience, the historic Mercury-Redstone 3 (MR-3) spacecraft was launched from Cape Canaveral Florida at 9:34 a.m. Eastern Time on May 5, 1961. The flight of Freedom 7, the first space flight by an American, followed less than a month after the first human venture into space by Soviet Cosmonaut Yuri Gagarin. The 15 minute sub-orbital flight achieved an altitude of 116 miles and a maximum speed of 5,134 miles per hour. As Shepard looked back near the peak of Freedom 7's trajectory, he could see the outlines of the west coast of Florida, Lake Okeechobe in central Florida, the Gulf of Mexico, and the Bahamas. Shepard would later view planet Earth from a more distant perspective and walk on the Moon as commander of the Apollo 14 mission.


Ricky Arnold

Astronaut Ricky Arnold is shown on his first spacewalk as a crewmember on STS-119.

Before he joined the Astronaut Corps, Arnold was a teacher, who taught all over the world from Malaysia to Romania. Arnold also served aboard the International Space Station on Expedition 55/56. 

In this image, during the six-hour, seven-minute spacewalk, Arnold and fellow astronaut Steve Swanson (out of frame) connected bolts to permanently attach the S6 truss segment to S5. The spacewalkers plugged in power and data connectors to the truss, prepared a radiator to cool it, opened boxes containing the new solar arrays and deployed the Beta Gimbal Assemblies containing masts that support the solar arrays. The blackness of space and Earth's horizon provide the backdrop for the scene.

Video – NASA STEM Stars: Astronaut Ricky Arnold for Teacher Appreciation Week

#TeacherAppreciationWeek

Image Credit: NASA


Source: www.nasa.gov

NGC 3199 lies about 12,000 light-years away, a glowing cosmic cloud in the nautical southern constellation of Carina. The nebula is about 75 light-years across in this narrowband, false-color view. Though the deep image reveals a more or less complete bubble shape, it does look very lopsided with a much brighter edge along the top. Near the center is a Wolf-Rayet star, a massive, hot, short-lived star that generates an intense stellar wind. In fact, Wolf-Rayet stars are known to create nebulae with interesting shapes as their powerful winds sweep up surrounding interstellar material. In this case, the bright edge was thought to indicate a bow shock produced as the star plowed through a uniform medium, like a boat through water. But measurements have shown the star is not really moving directly toward the bright edge. So a more likely explanation is that the material surrounding the star is not uniform, but clumped and denser near the bright edge of windblown NGC 3199.


President Kennedy Awards Alan Shepard NASA's Distinguished Service Medal

On May 5, 1961, Alan Shepard – one of NASA's first seven astronauts – became the first American in space.

In this image, President John F. Kennedy, right, awards NASA's Distinguished Service Medal to astronaut Shepard in a Rose Garden ceremony on May 8, 1961, at the White House. In the background are the other members of the Mercury Seven, NASA's original astronauts.

Shepard's Freedom 7 Mercury capsule flew a suborbital trajectory lasting 15 minutes 22 seconds. His spacecraft landed in the Atlantic Ocean where he and his capsule were recovered by helicopter and transported to the awaiting aircraft carrier U.S.S. Lake Champlain.

View the Alan Shepard image gallery.

Image Credit: NASA


Source: www.nasa.gov

What creates STEVEs? Strong Thermal Emission Velocity Enhancements (STEVEs) have likely been seen since antiquity, but only in the past five years has it been realized that their colors and shapes make them different from auroras. Seen as single bright streaks of pink and purple, the origin of STEVEs remain an active topic of research. STEVEs may be related to subauroral ion drifts (SAIDs), a supersonic river of hot atmospheric ions. For reasons currently unknown, STEVEs are frequently accompanied by green "picket-fence" auroras. The featured STEVE image is a combination of foreground and background exposures taken consecutively in mid-March from Copper Harbor, Michigan, USA. This bright STEVE lasted several minutes, spanned from horizon to horizon, and appeared in between times of normal auroras.


Illustration of a planet silhouetted by two suns

May the Fourth Be With You!

When the the first Star Wars movie was released in 1977, it featured the now-iconic two-sun, “circumbinary” planet Tatooine. At that time astronomers didn’t really know if such solar systems existed. Indeed, the first extra-solar planet wasn’t detected until the early 1990s. And, the first actual circumbinary planet was detected in 2005, and it was a Jupiter-size planet orbiting a system composed of a sun-like star and a brown dwarf. 

Fast forward a few decades and researchers working with data from the Transiting Exoplanet Survey Satellite (TESS) discovered the mission’s first circumbinary planet, a world orbiting two stars, as shown in this image from January 2020. The planet, called TOI 1338 b, is around 6.9 times larger than Earth, or between the sizes of Neptune and Saturn. It lies in a system 1,300 light-years away in the constellation Pictor.

The stars in the system make an eclipsing binary, which occurs when the stellar companions circle each other in our plane of view. One is about 10% more massive than our Sun, while the other is cooler, dimmer and only one-third the Sun’s mass. TOI 1338 b’s transits are irregular, between every 93 and 95 days, and vary in depth and duration thanks to the orbital motion of its stars. TESS only sees the transits crossing the larger star — the transits of the smaller star are too faint to detect. Its orbit is stable for at least the next 10 million years. The orbit’s angle to us, however, changes enough that the planet transit will cease after November 2023 and resume eight years later.

Image Credit: NASA/Goddard Space Flight Center


Source: www.nasa.gov

That's no sunspot. It's the International Space Station (ISS) caught passing in front of the Sun. Sunspots, individually, have a dark central umbra, a lighter surrounding penumbra, and no Dragon capsules attached. By contrast, the ISS is a complex and multi-spired mechanism, one of the largest and most complicated spacecraft ever created by humanity. Also, sunspots circle the Sun, whereas the ISS orbits the Earth. Transiting the Sun is not very unusual for the ISS, which orbits the Earth about every 90 minutes, but getting one's location, timing and equipment just right for a great image is rare. The featured picture combined three images all taken from the same location and at nearly the same time. One image -- overexposed -- captured the faint prominences seen across the top of the Sun, a second image -- underexposed -- captured the complex texture of the Sun's chromosphere, while the third image -- the hardest to get -- captured the space station as it shot across the Sun in a fraction of a second. Close inspection of the space station's silhouette even reveals a docked Dragon Crew capsule.



After the most famous voyage of modern times, it was time to go home. After proving that humanity has the ability to go beyond the confines of planet Earth, the first humans to walk on another world -- Neil Armstrong and Buzz Aldrin -- flew the ascent stage of their Lunar Module back to meet Michael Collins in the moon-orbiting Command and Service Module. Pictured here on 1969 July 21 and recently digitally restored, the ascending spaceship was captured by Collins making its approach, with the Moon below, and Earth far in the distance. The smooth, dark area on the lunar surface is Mare Smythii located just below the equator on the extreme eastern edge of the Moon's near side. It is said of this iconic image that every person but one was in front of the camera.

- NASA Remembers Michael Collins -


What forms lurk in the mists of the Carina Nebula? The dark ominous figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque. In comparison, however, these clouds are typically much less dense than Earth's atmosphere. Featured here is a detailed image of the core of the Carina Nebula, a part where both dark and colorful clouds of gas and dust are particularly prominent. The image was captured in mid-2016 from Siding Spring Observatory in Australia. Although the nebula is predominantly composed of hydrogen gas -- here colored green, the image was assigned colors so that light emitted by trace amounts of sulfur and oxygen appear red and blue, respectively. The entire Carina Nebula, cataloged as NGC 3372, 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.



Flying at an altitude of 5 meters (just over 16 feet), on April 25 the Ingenuity helicopter snapped this sharp image. On its second flight above the surface of Mars, its color camera was looking back toward Ingenuity's current base at Wright Brothers Field and Octavia E. Butler Landing marked by the tracks of the Perseverance rover at the top of the frame. Perseverance itself looks on from the upper left corner about 85 meters away. Tips of Ingenuity's landing legs just peek over the left and right edges of the camera's field of view. Its record setting fourth flight completed on April 30, Ingenuity collected images of a potential new landing zone before returning to Wright Brothers Field. Ingenuity's fifth flight would be one-way though as the Mars aircraft moves on to the new airfield, anticipating a new phase of operational demonstration flights.



On April 25 a nearly full moon rose just before sunset. Welcomed in a clear blue sky and framed by cherry blossoms, its familiar face was captured in this snapshot from Leith, Edinburgh, Scotland. Known to some as a Pink Moon, April's full lunar phase occurred with the moon near perigee. That's the closest point in its not-quite-circular orbit around planet Earth, making this Pink Moon one of the closest and brightest full moons of the year. If you missed it, don't worry. Your next chance to see a full perigee moon will be on May 26. Known to some as a Flower Moon, May's full moon will actually be closer to you than April's by about 98 miles (158 kilometers), or about 0.04% the distance from the Earth to the Moon at perigee.



Our fair planet sports a curved, sunlit crescent against the black backdrop of space in this stunning photograph. From the unfamiliar perspective, the Earth is small and, like a telescopic image of a distant planet, the entire horizon is completely within the field of view. Enjoyed by crews on board the International Space Station, only much closer views of the planet are possible from low Earth orbit. Orbiting the planet once every 90 minutes, a spectacle of clouds, oceans, and continents scrolls beneath them with the partial arc of the planet's edge in the distance. But this digitally restored image presents a view so far only achieved by 24 humans, Apollo astronauts who traveled to the Moon and back again between 1968 and 1972. The original photograph, AS17-152-23420, was taken by the homeward bound crew of Apollo 17, on December 17, 1972. For now it's the last picture of Earth from this planetary perspective taken by human hands.

- NASA Remembers Michael Collins -

Plants grown on the ISS

Astronauts on the International Space Station recently enjoyed a fresh supply of leafy greens, thanks in large part to the efforts of Expedition 64 crew member Michael Hopkins.

NASA’s SpaceX Crew-1 mission commander took the lead on conducting four Vegetable Production System (Veggie) experiments, with the last two wrapping up after an April 13 harvest. VEG-03K and VEG-03L tested a new space crop, ‘Amara’ mustard, and a previously grown crop, ‘Extra Dwarf’ pak choi. They were grown for 64 days, the longest leafy greens have grown on station.

Learn more about growing veggies on station.

Image Credit: NASA


Source: www.nasa.gov

Why is Polaris called the North Star? First, Polaris is the nearest bright star toward the north spin axis of the Earth. Therefore, as the Earth turns, stars appear to revolve around Polaris, but Polaris itself always stays in the same northerly direction -- making it the North Star. Since no bright star is near the south spin axis of the Earth, there is currently no South Star. Thousands of years ago, Earth's spin axis pointed in a slightly different direction so that Vega was the North Star. Although Polaris is not the brightest star on the sky, it is easily located because it is nearly aligned with two stars in the cup of the Big Dipper. Polaris is near the center of the eight-degree wide featured image, an image that has been digitally manipulated to suppress surrounding dim stars but accentuate the faint gas and dust of the Intergalactic Flux Nebula (IFN). The surface of Cepheid Polaris slowly pulsates, causing the star to change its brightness by a few percent over the course of a few days.

Portal Universe: Random APOD Generator

The SpaceX Crew Dragon Endeavour approaches the space station

This image from April 24, 2021, shows the SpaceX Crew Dragon Endeavour as it approached the International Space Station less than one day after launching from Kennedy Space Center in Florida. The SpaceX Crew-2 astronauts, Commander Shane Kimbrough and pilot Megan McArthur with astronauts Akihiko Hoshide of the Japan Aerospace Exploration Agency and Thomas Pesquet of the European Space Agency, joined the Expedition 65 crew shortly after docking to the Harmony module's forward-facing international docking adapter.

Image Credit: NASA


Source: www.nasa.gov
Supernova remnant Cassiopeia A (Cas A),

Scientists have found fragments of titanium blasting out of a famous supernova. This discovery, made with NASA’s Chandra X-ray Observatory, could be a major step in pinpointing exactly how some giant stars explode.

This work is based on Chandra observations of the remains of a supernova called Cassiopeia A, located in our galaxy about 11,000 light-years from Earth. This is one of the youngest known supernova remnants, with an age of about 350 years.

Image Credit: NASA/CXC/RIKEN/T. Sato et al.; NuSTAR: NASA/NuSTAR)


Source: www.nasa.gov

These three bright nebulae are often featured on telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula below and right of center, and colorful M20 near the top of the frame. The third emission region includes NGC 6559, left of M8 and separated from the larger nebula by a dark dust lane. All three are stellar nurseries about five thousand light-years or so distant. Over a hundred light-years across the expansive M8 is also known as the Lagoon Nebula. M20's popular moniker is the Trifid. Glowing hydrogen gas creates the dominant red color of the emission nebulae. But for striking contrast, blue hues in the Trifid are due to dust reflected starlight. The broad interstellarscape spans almost 4 degrees or 8 full moons on the sky.



Why isn't this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round? Clues might include the high 1000-kilometer per second speed of the expelled gas, the light-year long length of the structure, and the magnetism of the star featured here at the nebula's center. One possible answer is that Mz3 is hiding a second, dimmer star that orbits close in to the bright star. A competing hypothesis holds that the central star's own spin and magnetic field are channeling the gas. Since the central star appears to be so similar to our own Sun, astronomers hope that increased understanding of the history of this giant space ant can provide useful insight into the likely future of our own Sun and Earth.


SpaceX Crew-2 Launch

A SpaceX Falcon 9 rocket carrying the company's Crew Dragon spacecraft is seen to the right of the U.S. Capitol Building in Washington as it launches NASA’s SpaceX Crew-2 mission to the International Space Station with NASA astronauts Shane Kimbrough and Megan McArthur, ESA (European Space Agency) astronaut Thomas Pesquet, and Japan Aerospace Exploration Agency (JAXA) astronaut Akihiko Hoshide onboard, Friday, April 23, 2021, from Cape Canaveral, Florida. NASA’s Crew-2 mission is the second crew rotation mission of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the space station as part of the agency’s Commercial Crew Program. Kimbrough, McArthur, Pesquet, and Hoshide launched at 5:49 a.m. EDT from Launch Complex 39A at the Kennedy Space Center to begin a six-month mission onboard the orbital outpost. 

This image, and others, are available on Flickr: https://flic.kr/s/aHsmVnkHwE

Image Credit: NASA/Bill Ingalls


Source: www.nasa.gov