2026 March 29

A Message from Earth
Image Credit: Frank Drake et al., Arecibo Observatory;
License: Arne Nordmann (Wikimedia)

What are these Earthlings trying to tell us? The featured message was broadcast from Earth towards the globular star cluster M13 in 1974. During the dedication of an upgrade to the Arecibo Observatory - then the largest single radio telescope in the world - a string of 1's and 0's representing the diagram was sent. This attempt at extraterrestrial communication was mostly ceremonial - humanity regularly broadcasts radio and television signals out into space accidentally. Even were this message received, M13 is so far away we would have to wait almost 50,000 years to hear an answer. The featured message gives a few simple facts about humanity and its knowledge: from left to right are numbers from one to ten, atoms including hydrogen and carbon, some interesting molecules, DNA, a human with description, basics of our Solar System, and basics of the sending telescope. Several searches for extraterrestrial intelligence are currently underway.

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2026 March 30

Peculiar Elliptical Galaxy Centaurus A
Image Credit & Copyright: SADR Observatory Team: J-C Dalouzy, P. Bazart, M. Dherbécourt, C. Humbert, G. Leroy, J-P Quéau, H. Talbot, & E. Valin

What's happened to the center of this galaxy? Dramatic dust lanes run across the center of unusual elliptical galaxy Centaurus A. These dust lanes are so thick they almost completely obscure the galaxy's center in visible light. This is particularly unusual as Cen A's older stars and oval shape are characteristic of a giant elliptical galaxy, a galaxy type typically low in dark dust. Pictured in this deep image is a complex network of foreground gas and dust, as well as shells of dim stars and a jet projecting to the upper right. Also known as NGC 5128, Cen A is surely the result of a galactic collision where many young dust-creating stars were formed. However, details of the creation of Cen A's unusually active center and iconic central dust lanes are still being researched. Cen A lies only 13 million light years away, making it the closest active galaxy.

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2026 March 31

Uranus's Largest Moon: Titania
Image Credit: NASA, Voyager 2; Processing & License: zelario12

Titania's tortured terrain is a mix of canyons, cliffs, and craters. NASA's interplanetary robot spacecraft Voyager 2 passed the largest moon of Uranus in 1986 and took the feature picture. That the trenches of Titania resemble those on another moon of Uranus, Ariel, indicate that Titania underwent some violent surface event possibly related to water freezing and expanding in its distant past. Although Titania is Uranus's largest moon, it is only about half the radius of Triton - the largest moon of Uranus's sister planet Neptune, which itself is slightly smaller than Earth's Moon. Titania, discovered by William Herschel in 1787, is essentially a large dirty iceball that is composed of about half water-ice and half rock. There is recent speculation that radioactive heating melts some underground ice into oceans.

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2026 April 1

The Claw and Bubble Nebulae
Image Credit & Copyright: Richard Whitehead
Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST II)

What unexpected things do you see when you look up at the night sky? Today’s image resembles an abstract painting, with large swaths of color strewn across a cosmic canvas seemingly without design. Despite the image's abstract nature, the human mind finds patterns, identifying a large claw reaching up towards a floating bubble. Embedded within these seemingly random structures are the physical laws that govern how light and matter interact. The Claw (Sh2-157) and Bubble (NGC 7635) Nebulae glow colors that are mapped to the yellow and blue shown, indicating the presence of hydrogen and oxygen ionized by the intense light emitted from stars several times the mass of the Sun. This image depicts both the chaos and structure of astronomical processes, showing that a common thread between art and science is to look for the unexpected.

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2026 April 2

Liftoff! Returning to the Moon
Image Credit & Copyright: NASA/Bill Ingalls; Text: Ogetay Kayali (MTU)

We are one small step closer to returning to the Moon. A new chapter in human exploration began yesterday when NASA's Artemis II launched aboard the Space Launch System (SLS) from Kennedy Space Center. Carrying four astronauts, the Orion spacecraft's planned lunar flyby will be the first in over half a century. This historic test flight, echoing the legacy of Apollo while pushing beyond it, will carry its crew farther from Earth than any humans since 1972, looping around the Moon before returning home. During the approximately ten-day journey, Orion's systems--from life support to navigation--will be tested in deep space, while astronauts observe the lunar surface, including shadowed regions of the far side rarely seen with such perspective. After looping around the Moon, the astronauts will return to Earth, ending their journey with a Pacific Ocean splashdown.

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2026 April 3

Caught in the Web: Visualization of a Black Hole Merger in the Tarantula Nebula
Illustration Credit & Copyright: Artwork: Carl Knox (OzGrav, Swinburne University of Technology);
Astrophotography: Blake Estes & Christian Sasse, iTelescope.net; Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)

How can we see what is invisible? Black holes are not easy to see in the dark cosmic night, but astronomers can find them by analyzing their gravitational effects on matter, light and spacetime. The featured image shows an illustration that combines a simulation of a black hole binary system in its final "death-dance" with an astrophotography image of the Tarantula Nebula in the background. Even though black holes don't emit light, they distort the path of light rays, acting like a gravitational lens. As a result, the nebula appears extremely distorted, forming Einstein rings and multiple images. Tarantula Nebula lies in the Large Magellanic Cloud, a dwarf galaxy that is one of the satellite galaxies of the Milky Way, 160,000 light-years away. That is more than 1,000 times closer than any of the binary black hole mergers detected so far. We'll probably never detect a merger so close to home!

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2026 April 4

Hello World
Image Credit: NASA, Reid Wiseman, Artemis II

From pole to pole our fair planet is captured in this snapshot from space, an evocative image from a window of the Orion spacecraft Integrity. From the spacecraft's perspective the Sun is moving behind Earth's bright limb along the lower right. Africa and the Iberian peninsula are in view on the pale blue planet's surface, while aurorae crown Earth's south and north poles at top right and bottom left. Commander Reid Wiseman took the historic picture on Artemis II mission flight day 2 (April 2), after the completion of the planned translunar injection burn. That burn boosted the spacecraft out of Earth orbit, sending Integrity and crew on a trajectory that will take them around the Moon and back again. That's a journey humans last made over 50 years ago. (Editor's note: Venus is photobombing Wiseman's historic pic. Currently appearing in our western skies after sunset, the inner planet is in the frame below and right of Earth's bright limb, immersed in a faint band of zodiacal light.)

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2026 April 5

NGC 3310: A Starburst Spiral Galaxy
Image Credit & Copyright: AAO ITSO Office, Gemini Obs./AURA & T. A. Rector (U. Alaska Anchorage)

The party is still going on in spiral galaxy NGC 3310. Roughly 100 million years ago, NGC 3310 likely collided with a smaller galaxy causing the large spiral galaxy to light up with a tremendous burst of star formation. The changing gravity during the collision created density waves that compressed existing clouds of gas and triggered the star-forming party. The featured image from the Gemini North Telescope shows the galaxy in great detail, color-coded so that pink highlights gas while white and blue highlight stars. Some of the star clusters in the galaxy are quite young, indicating that starburst galaxies may remain in star-burst mode for quite some time. NGC 3310 spans about 50,000 light years, lies about 50 million light years away, and is visible with a small telescope towards the constellation of Great Bear Ursa Major.

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2026 April 6

The Path of Artemis II
Video Credit: NASA, GSFC, Artemis II, SVS

Why doesn't Artemis II land on the Moon? The main reason is that Artemis II is primarily a test mission designed to make a future Artemis missions -- which will land humans on the Moon -- better prepared. Similarly, NASA's Apollo 8 and Apollo 10 went right near the Moon as tests before Apollo 11 -- which landed. As the trajectory in the featured animated video shows, Artemis II will loop around both the Earth and the Moon before returning to the Earth about 10 days after launch. The Artemis II mission will take humans outside the Earth's magnetosphere for the first time since the Apollo missions 50 years ago. In the video, particles from the solar wind are shown as streaks, while the Earth's reacting magnetosphere is shown in flickering green. The Earth's magnetosphere is important in deflecting powerful particles arriving from the Sun as well as creating picturesque auroras visible from the Earth's surface.

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2026 April 7

IC 4592: The Blue Horsehead Reflection Nebula
Image Credit & Copyright: Rabeea Alkuwari

Do you see the horse's head? What you are seeing is not the famous Horsehead nebula toward Orion, but rather a fainter nebula that only takes on a familiar form with deeper imaging. The main part of the here-imaged molecular cloud complex is reflection nebula IC 4592. Reflection nebulas are made up of very fine dust that normally appears dark but can look quite blue when reflecting the visible light of energetic nearby stars. In this case, the source of much of the reflected light is a star at the eye of the horse. That star is part of Nu Scorpii, one of the brighter star systems toward the constellation of the Scorpion (Scorpius). A second reflection nebula dubbed IC 4601 is visible surrounding two stars just below the image center. The featured picture was taken from Sawda Natheel in Qatar.

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2026 April 8

Earthset
Image Credit: NASA
Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST II)

"And to all of you down there on Earth and around Earth, we love you, from the Moon. We will see you on the other side", said Artemis II pilot Victor Glover on April 6th at 6:44pm ET as 8.3 billion minus four people and one Earth set below the Moon's horizon. The Orion spacecraft, Integrity, then traveled behind the Moon as part of its seven-hour lunar flyby. The crew characterized never-before-seen regions of the far side of the Moon, which is puzzlingly less volcanically active than the near side. New observations of crater peaks, floors, terraces, and rings preserved on the lunar surface will help piece together the impact history of the Solar System. Among many other surface characterizations, the crew observed one of the Moon's best-preserved basins, the Orientale basin, and identified two new craters. As Earth rose above the Moon’s horizon and Integrity began its return home, Artemis II mission specialist Christina Koch powerfully summarized humanity’s grander mission: "...we will always choose Earth. We will always choose each other."

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2026 April 9

Destruction of Comet C/2026 A1 (MAPS)
Video Credit: Brian Day, SOHO, SDO, JHelioviewer
Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)

As the crew of Artemis II travelled towards the Moon this week, Comet C/2026 A1 (MAPS) was expected to have its closest approach to the Sun on Monday. At this point, comet and Sun would be closer than half the distance separating the Earth and Moon. The comet did not survive; the featured video was made with 40 hours of data and shows the comet plunging toward the Sun, like a moth to a flame. Observing the comet so close to our bright star requires a coronagraph, an instrument that blocks the Sun and is used for studies of its corona. This composite video combines, starting from the outside, views from: the wider angle coronagraph (blue) and the narrower angle coronagraph (red), both on NASA's Solar and Heliospheric Observatory, and NASA's Solar Dynamics Observatory (black). We can see the comet approaching the sun, stretching, disappearing behind the coronagraph's occulting disk and reappearing as a cloud of debris that dissipates.

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2026 April 10

Exploring the Antennae
Image Credit & Copyright: Acquisition - Mike Selby Processing - Roberto Colombari

Some 60 million light-years away in the southerly constellation Corvus, two large galaxies are colliding. Stars in the two galaxies, cataloged as NGC 4038 and NGC 4039, very rarely collide in the course of the ponderous cataclysm that lasts for hundreds of millions of years. But the galaxies' large clouds of molecular gas and dust often do, triggering furious episodes of star formation near the center of the cosmic wreckage. Spanning over 50 thousand light-years, this stunning telescopic frame also reveals new star clusters and matter flung far from the scene of the accident by gravitational tidal forces. The remarkably sharp ground-based image follows the faint tidal tails and distant background galaxies in the field of view. The suggestive overall visual appearance of the extended arcing structures gives the galaxy pair, also known as Arp 244, its popular name - The Antennae.

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2026 April 11

Artemis II: Flight Day 6
Image Credit: NASA, Artemis II

On flight day 6 (April 6) the Artemis II mission achieved a historic lunar flyby. Rounding the lunar far side, the deep space maneuver marked humanity's first venture to the Moon since Apollo 17 in 1972. The Orion spacecraft Integrity reached a maximum distance of nearly 407,000 kilometers, and the Artemis II crew, Reid Wiseman, Victor Glover, and Christina Koch, and Jeremy Hansen, set the record for the farthest distance from Earth traveled by any human since the Apollo 13 crew in 1970. From behind the Moon on flight day 6, a solar array wing camera recorded this space age selfie, framing the spacecraft and lunar far side. Planet Earth, home to the Artemis II crew, is the small, bright crescent beyond the lunar limb. The crew safely returned home on Artemis II mission flight day 10.

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2026 April 12

Comet R3 (PanSTARRS) Brightens
Image Credit & Copyright: José Rodrigues

Comet R3 is brightening rapidly -- will it survive? C/2025 R3 (PanSTARRS) has been slowly brightening and extending an ion tail since its discovery last year. This shedding mountain of dirty ice puts on its best sky show this month, though, because it passes its closest to both the Sun (April 19) and the Earth (April 25). The featured image, showing R3 already sporting a tail extending over 10 degrees, was taken two nights ago from Sion, Switzerland with the big mountain Bietschhorn on the left. Comet R3 will be visible during mid-April before sunrise. Although the future brightness of any comet is hard to predict, the brightness of R3 makes it already a good camera comet and it may become visible to the unaided eye in the next week. Comet R3's physical future is also unknown because, like Comet A1 (MAPS) earlier this month, it may disintegrate when it passes its closest to the Sun. Or it may live to leave the Solar System.

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2026 April 13

NGC 602 and Beyond
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) - ESA/Hubble Collaboration

The clouds may look like an oyster, and the stars like pearls, but look beyond. Near the outskirts of the Small Magellanic Cloud, a satellite galaxy some 200 thousand light-years distant, lies 5 million year young star cluster NGC 602. Surrounded by natal gas and dust, NGC 602 is featured in this stunning Hubble image of the region. Fantastic ridges and swept back shapes strongly suggest that energetic radiation and shock waves from NGC 602's massive young stars have eroded the dusty material and triggered a progression of star formation moving away from the cluster's center. At the estimated distance of the Small Magellanic Cloud, the featured picture spans about 200 light-years, but a tantalizing assortment of background galaxies are also visible in this sharp multi-colored view. The background galaxies are hundreds of millions of light-years or more beyond NGC 602.

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2026 April 14

The Long Wispy Tail of Comet R3 (PanSTARRS)
Image Credit & Copyright: Haythem Hamdi

Why does Comet R3 (PanSTARRS) have a wispy tail? The newest bright member of the inner Solar System, Comet C/2025 R3 (PanSTARRS) is already extending an impressive stream of glowing gas. This tail starts from an unseen central nucleus of dirty ice that is likely a few kilometers across. The nucleus is warmed by the Sun and emits a cloud of neutral gas into a coma that glows light green. Nuclear gas ionized by energetic sunlight is pushed away from the Sun by the solar wind into an ion tail that glows light blue. The wispy nature of the ion tail is caused by the constantly changing structure of the solar wind. Pictured from Rhode Island, USA two days ago, Comet R3 (PanSTARRS) shows off a many-degree ion tail. Comet R3 (PanSTARRS) is best seen before dawn from northern skies for another 10 days, after which it will be best visible from southern skies.

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2026 April 15

The ISS Transits the Moon
Image Credit & Copyright: Sébastien Borie
Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST II)

Nope, that is not an alien spaceship landing on the Moon! This is an image of the International Space Station (ISS) as it begins to transit in front of the Moon. The ISS is in low-Earth orbit (LEO) where it wizzes around the Earth every 90 minutes. Orbiting the Earth 16 times per day for 25 years, the ISS has photobombed many familiar celestial objects including Venus, Mars, Saturn, and the Sun. Thousands of experiments led by researchers from over one hundred countries have been conducted on the ISS. Growing protein crystals in low gravity was one of the first experiments onboard the ISS and continues to contribute to new medical treatments. ISS astronauts study plant growth, water recycling, human health, and more to support the Artemis missions which will take humans farther than they’ve ever gone before. Next time you are out and about at night, try to spot the ISS zooming across the sky!

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2026 April 16

South Celestial Tree
Image Credit & Copyright: Kiko Fairbairn
Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)

If you live in the northern hemisphere, you may have learned how to locate the North Star, Polaris, in the night sky. It can be used to find north, and it approximately marks the northern celestial pole. If you live in the southern hemisphere, there is no bright star marking the southern celestial pole, but the Southern Cross can be used to find south. The featured image was taken in Padre Bernardo (GO), Brazil. It shows the apparent motion of the stars around the apparently empty southern celestial pole over 2 hours, on August 20, 2018. Each star takes about 24 hours to make a complete turn around the pole in the sky. Padre Bernardo is located in the Cerrado region, a tropical savanna that occupies most of central Brazil and supports rich biodiversity. The barren branch that apparently supports this sky wheel of rotating stars is a common sight there in the dry season during the southern winter.

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2026 April 17

M82: Starburst Galaxy with a Superwind
Image Credit & Copyright: Arnaud Malleval

Messier 82 is a starburst galaxy with a superwind. In fact, through supernova explosions and powerful winds from massive stars, the burst of star formation in M82 is driving a prodigious outflow. Evidence for the superwind from the galaxy's central regions is clear in the sharp telescopic portrait. The composite image includes 33 hours of narrowband data, highlighting emission from long outflow filaments of atomic hydrogen gas in reddish hues. Some of the gas in the superwind, enriched in heavy elements forged in the massive stars, will eventually escape into intergalactic space. Triggered by a close encounter with nearby large galaxy M81, the furious burst of star formation in M82 should last about 100 million years or so. Also known as the Cigar Galaxy for its elongated visual appearance, M82 is about 30,000 light-years across. It lies 12 million light-years away near the northern boundary of Ursa Major.

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