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June 2025

NASA Science Calendar Image of the Month. Image credit: NASA/Jet Propulsion Laboratory (JPL)–Caltech/University of Arizona

Colorful composite image of the supernova remnant Cassiopeia A, showing intricate, glowing filaments in blue, red, green, and yellow. Captured using NASA’s James Webb and Chandra telescopes, the image reveals expanding shockwaves and stellar debris from the exploded star, set against a star-filled background.

June 2025 Image

Learn about June's amazing image. Explore related topics, activities, games, and download desktop wallpaper.

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The “Green Monster”

  • For the first time, astronomers have combined data from NASA’s Chandra X-ray Observatory and James Webb Space Telescope to study the well-known supernova remnant Cassiopeia A (Cas A). This work has helped explain an unusual structure in the debris from the destroyed star called the “Green Monster,” first discovered in Webb data in April 2023. The area of the Green Monster is outlined in the inset image. This composite image contains X-rays from Chandra (blue), infrared data from Webb (red, green, blue), and optical data from Hubble (red and white). The outer parts of the image also include infrared data from NASA’s Spitzer Space Telescope (red, green, and blue).

    Learn more about Cassiopeia A

    A desktop computer monitor displaying Colorful composite image of the supernova remnant Cassiopeia A

Discover More about Supernovas

Two learners playing the game look at the board to find the planetary body in question

Exploring the Universe: Space Guess Quest Game

In this activity, learners play a yes-or-no question guessing game that identifies the many types of objects in space, from human-made spacecraft to nebulas, galaxies, stars, and worlds.

Play Space Guess Quest
Person's hand pointing to Nebula Spin Art activity with black paper circles covered with paint

Exploring the Universe: Nebula Spin Art

In this activity, learners create their own colorful model nebula using paint and a spinner.

Create Nebula Spin Art
3D-printed model of the Cassiopeia A supernova remnant, showing an irregular, cloud-like structure with bulbous extensions, displayed against a black background.

3D print a supernova remnant

3D print a model of Cassiopeia A, the 300-year old remains of a stellar explosion that blew a massive star apart.

Print Your Own Supernova Remnant
Colorful composite image of the supernova remnant Cassiopeia A, showing intricate, glowing filaments in blue, red, green, and yellow. Captured using NASA’s James Webb and Chandra telescopes, the image reveals expanding shockwaves and stellar debris from the exploded star, set against a star-filled background.

Cassiopeia A Resources

Curated list of assets related to Cassiopeia A intended to provide educators context and activities to talk about supernova.

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Composite image of the Crab Nebula, showing a vibrant cloud of gas and dust with filaments in yellow, red, and blue, radiating from a bright central region. The image combines data from NASA’s Hubble, Chandra, and Spitzer telescopes.

Crab Nebula: The Multiwavelength Structure of a Pulsar Wind Nebula

3D visualization of the Crab Nebula using data from NASA's three Great Observatories - the Chandra X-ray Observatory and the Hubble and Spitzer space telescopes

Explore Crab Nebula
Composite image of the Cassiopeia A supernova remnant with annotated labels. A dashed outline highlights the central region marked “Near-infrared clues of Green Monster,” and another label points to “Knots of gas” along the outer edges. The image shows colorful filaments and glowing gas structures against a star-filled background.

ViewSpace Slider: Star Death: Cassiopeia A

Interactive slider that showcases Cassiopeia A in multiple wavelengths.

Explore Cassiopeia A

Meet Our Flying Missions

  • NASA’s Astrophysics Division explores the universe, pushes the boundaries of cosmic knowledge, and shares discoveries with the world. It expands our understanding of how the universe began, evolved, and whether life might exist beyond Earth. In collaboration with global partners, NASA researchers tackle big questions about life, the universe’s origins, and its workings through cutting-edge science and technology.

    Explore Our Missions

Explore our other featured images

Explore NASA's media galleries to view and download high-resolution images of the solar system, agency missions, and more.

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January 2025

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February 2025

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Colorful composite image of the supernova remnant Cassiopeia A, showing intricate, glowing filaments in blue, red, green, and yellow. Captured using NASA’s James Webb and Chandra telescopes, the image reveals expanding shockwaves and stellar debris from the exploded star, set against a star-filled background.

June 2025

Supernova