Uranus’ Moon Ariel has Deep Gashes, Could Reveal its Interior

Voyager 2 captured this image of Uranus' moon Ariel in 1986 from 130,000 km away. New research based largely on this image hints at the nature of the moon's interior. Image Credit: By NASA/JPL - https://www.jpl.nasa.gov/images/pia00037-ariel-at-voyager-closest-approach, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1110562

We’ve only gotten one close-up view of Uranus and its moons, and it happened decades ago. In 1986, Voyager 2 performed a flyby of Uranus from about 81,500 km (50,600 mi) of the planet’s cloud tops. It was 130,000 km (80,000 mi) away from Uranus’ moon, Ariel, when it captured the leading image. It showed some unusual features that scientists are still puzzling over.

What do they reveal about the moon’s interior?

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A Super-Earth to Test the Limits of Habitability

This illustration shows the habitable zone around the star HD 20794 (in green) and the trajectory of the three planets in the system. One of the planets moves through both the optimistic and pessimistic habitable zones. Image © Gabriel Pérez Díaz, SMM (IAC)

Every exoplanet discovery is an opportunity to refine models of planet formation, solar system architecture, habitable zones, and habitability itself. Each new planet injects more data into the scientific endeavour to understand what’s going on and how things got this way. However, some planets have such unusual characteristics that they invite a deeper focus and intense follow-up observations.

That’s the case for one new exoplanet. It’s a super-Earth on an unusual orbit that’s giving astronomers an opportunity to test the ideas of habitability and optimistic and pessimistic habitable zones.

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It’s Time to Start Classifying Exoplanetary Systems

This 2018 artist’s concept shows what the TRAPPIST-1 planetary system may look like, based on available data about the planets’ diameters, masses and distances from the host star (far left). According to a new exoplanet system architecture classification scheme, this system is a "peas in a pod" system. NASA/JPL-Caltech

When an exoplanet is discovered, scientists are quick to describe it and explain its properties. Now, we know of thousands of them, many of which are members of a planetary system, like the well-known TRAPPIST-1 family of planets.

Patterns are starting to emerge in these exoplanetary systems, and in new research, a team of scientists says it’s time to start classifying exoplanet systems rather than just individual planets.

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Why The First Stars Couldn’t Grow Forever

Population III stars were the Universe's first stars. They were extremely massive, luminous stars, and many of them exploded as supernovae. How did they shape the early galaxies? Image Credit: DALL-E
The hypothetical Population III stars were the Universe's first stars. They were extremely massive, luminous stars, and many of them exploded as supernovae. Image Credit: DALL-E

Star formation in the early Universe was a vigorous process that created gigantic stars. Called Population 3 stars, these giants were massive, extremely luminous stars, that lived short lives, many of which were ended when they exploded as primordial supernovae.

But even these early stars faced growth limitations.

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Sticks and Stones: The Molecular Clouds in the Heart of the Milky Way

Astronomers have created 3D maps of two giant molecular clouds in the Milky Way's Central Molecular Zone (CMZ). What happens to them in such an extreme environment? Image Credit: Alboslani et al. 2025.

The Central Molecular Zone (CMZ) at the heart of the Milky Way holds a lot of gas. It contains about 60 million solar masses of molecular gas in complexes of giant molecular clouds (GMCs), structures where stars usually form. Because of the presence of Sag. A*, the Milky Way’s supermassive black hole (SMBH), the CMZ is an extreme environment. The gas in the CMZ is ten times more dense, turbulent, and heated than gas elsewhere in the galaxy.

How do star-forming GMCs behave in such an extreme environment?

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About a Third of Supermassive Black Holes are Hiding

A supermassive black hole surrounded by a torus of gas and dust is depicted in four different wavelengths of light in this artist’s concept. Visible light (top right) and low-energy X-rays (bottom left) are blocked by the torus; infrared (top left) is scattered and reemitted; and some high energy X-rays (bottom right) can penetrate the torus. Image Credit: NASA/JPL-Caltech

Supermassive black holes can have trillions of times more mass than the Sun, only exist in specific locations, and could number in the trillions. How can objects like that be hiding? They’re shielded from our view by thick columns of gas and dust.

However, astronomers are developing a way to find them: by looking for donuts that glow in the infrared.

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The Webb Shows Us Where Cosmic Dust Comes From

Concentric rings of dust form around the pair of binary stars named Wolf-Rayet 140. The dust is formed when the stellar winds from the stars slam into each other every few years. Image Credit: NASA, ESA, CSA, STScI, JPL-Caltech

Carbon-rich cosmic dust comes from different sources and spreads out into space, where it’s necessary for life and for the formation of rocky planets like ours. When astronomers aim their telescopes at objects in the sky, they often have to contend with this cosmic dust that obscures their targets and confounds their observations.

One reason the JWST was built is to see through some of this dust with its infrared vision and unlock new insights into astrophysical processes. In new work, the JWST was tasked with observing the dust itself.

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Archaeology On Mars: Preserving Artifacts of Our Expansion Into the Solar System

There's something wistful about this image, one of the InSIGHT missions final ones before it succumbed to Mars' dust storms. One anthropologist points out that this is now a historical artifact worthy of preservation, as are other spacecraft and equipment on Mars. Image Credit: NASA/JPL-Caltech

In 1971, the Soviet Mars 3 lander became the first spacecraft to land on Mars, though it only lasted a couple of minutes before failing. More than 50 years later, it’s still there at Terra Sirenum. The HiRISE camera NASA’s Mars Reconnaissance Orbiter may have imaged some of its hardware, inadvertently taking part in what could be an effort to document our Martian artifacts.

Is it time to start cataloguing and even preserving these artifacts so we can preserve our history?

Some anthropologists think so.

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Add Astronaut Nutrition to the List of Barriers to Long-Duration Spaceflight

NASA Astronauts Kjell Lindgren (center) and Scott Kelly (right) and Kimiya Yui (left) of Japan consume space grown food for the first time ever, from the Veggie plant growth system on the International Space Station in August 2015. Credit: NASA TV

Though there are no firm plans for a crewed mission to Mars, we all know one’s coming. Astronauts routinely spend months at a time on the ISS, and we’ve learned a lot about the hazards astronauts face on long missions. However, Mars missions can take years, which presents a whole host of problems, including astronaut nutrition.

Nutrition can help astronauts manage spaceflight risks in the ISS, but long-duration missions to Mars are different. There can be no resupply.

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