Mars' Carbon Dioxide Glaciers are on the Move

Mars’ south polar ice cap. Credit: ESA / DLR / FU Berlin /

In 1666, famed Italian astronomer and mathematician Giovanni Cassini (the man who discovered four of Saturn’s largest moons) observed the Martian polar ice caps for the first time. However, it was not until the late-18th century, when Sir William Herschel recorded his own observations, that the connection to Earth’s own ice caps was established. In his subsequent treatise, “On the remarkable appearances at the polar regions on the planet Mars” (1784), noted how the southern cap grew and shrunk due to seasonal changes.

With the development of modern telescopes and robotic explorers, scientists have learned a great deal more about these polar deposits. In 2011, they learned that unlike the northermost ice sheet, the southern cap is largely composed of frozen carbon dioxide (aka. “dry ice”). According to new research led by the Planetary Science Institute (PSI), glaciers of carbon dioxide ice have been moving and carving features in the southern polar region for more than 600,000 years – and are on the move right now!

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Jupiter’s Moon Io has Dunes. Dunes!?

Potential dunes on Jupiter’s moon Io. An analysis indicates that the dark material (lower left) is recently emplaced lava flows, while the repeated, line-like features dominating the image are potential dunes. The bright, white areas may be newly emplaced grains as the lava flows vaporize adjacent frost. Credit: NASA/JPL-Caltech/Rutgers

Within Jupiter’s massive system of satellites, four large moons really stand out. They’re known as the “Galilean Moons” in honor of Galileo Galilee, who made the first recorded observations of them in 1610. The innermost of these moons is the rocky moon Io, which is slightly larger than Earth’s Moon and slightly denser. With more than 400 active volcanoes on its surface, it is the most geologically active body in the Solar System.

Add to that the intense radiation it gets from Jupiter’s magnetic field, and it’s arguably one of the most hellish environments in the Solar System! Nevertheless, scientists have long been puzzled by the meandering ridges visible on the surface, which are as large as any seen here on Earth. Thanks to a recent study led by Rutgers University, there’s now an explanation for how these formations can exist on a surface as icy and volcanic as Io’s.

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Marsquakes are Caused by Shifting Magma

Mars' interior as revealed by the NASA/DLR InSight lander. Image Credit: Cottar, Koelemeijer, Winterbourne, NASA

Before the InSight Lander arrived on Mars, scientists could only estimate what the planet’s internal structure might be. Its size, mass, and moment of inertia were their main clues. Meteorites, orbiters, and in-situ sampling by rovers provided other clues.

But when InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) arrived on Mars in November 2018 and deployed its seismometer, better data started streaming in.

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Primordial Helium, Left Over From the Big Bang, is Leaking Out of the Earth

The center of Lagoon Nebula, captured by the Hubble Telescope. Nebulae are the primary sources of helium-3, and the amount of He-3 leaking from the Earth’s core suggests the planet formed inside the solar nebula, according to a new study in the AGU journal Geochemistry, Geophysics, Geosystems. Credit: NASA, ESA

Something ancient and primordial lurks in Earth’s core. Helium 3 (3He) was created in the first minutes after the Big Bang, and some of it found its way through time and space to take up residence in Earth’s deepest regions. How do we know this?

Scientists can measure it as it slowly escapes.

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Pluto’s Surface was Shaped by Ice Volcanoes

New Horizons mission scientists have determined that cryovolcanic activity most likely created unique structures on Pluto not yet seen anywhere else in the solar system. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Isaac Herrera/Kelsi Singer

For all of Earth’s geological diversity and its long history, the planet has never had ice volcanoes. But Pluto has. And that cryovolcanism has shaped some of the ice dwarf’s surface features.

The resulting structures are unique in the Solar System.

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These are Star Dunes on Mars, Formed When the Wind Comes From Many Different Directions

An amazing aspect of Mars that is captured in many HiRISE images is geologic diversity within a small area. This image, of a crater in the Tyrrhena Terra region, was targeted to look at the geologic aspects of possible clays detected with the CRISM instrument. Image Credit: NASA/JPL/UArizona

Missions to Mars are expensive, even orbiters. They’re there to do science, not take pretty pictures. But sometimes Mars’ beauty is captured inadvertently, usually with some science mixed in.

That’s the case with this picture of star dunes captured by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter.

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The Strange Swirls on the Lunar Surface are Somehow Related to Topography

This is an image of the Reiner Gamma lunar swirl from NASA's Lunar Reconnaissance Orbiter. Credits: NASA LRO WAC science team
This is an image of the Reiner Gamma lunar swirl from NASA's Lunar Reconnaissance Orbiter. Credits: NASA LRO WAC science team

The Moon is the most studied object in space. But our nearest neighbour still holds a few mysteries. One of those mysteries is the lunar swirls. These strange serpentine features are brighter than their surroundings and are much younger. They’re not associated with any specific composition of lunar rock, and they appear to overlay other surface features like craters and ejecta.

Scientists have been puzzling over the swirls for decades, and with lunar outposts looming as a real possibility, understanding these swirls takes on new importance. Now a new study finds a link between lunar topography and the swirls.

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How did Earth go From Molten Hellscape to Habitable Planet?

An artist's impression of the Hadean eon. Image Credit: By Tim Bertelink - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=48916334

Earth formed from the Sun’s protoplanetary disk about 4.6 billion years ago. In the beginning, it was a molten spheroid with scorching temperatures. Over time, it cooled, and a solid crust formed. Eventually, the atmosphere cooled, and life became a possibility.

But how did all of that happen? The atmosphere was rich in carbon, and that carbon had to be removed before the temperature could drop and Earth could become habitable.

Where did all the carbon go?

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What’s it Like Inside a Super-Earth?

This artist’s impression shows a Super-Earth orbiting a Sun-like star. HD 85512 in the southern constellation of Vela (The Sail). This planet is one of sixteen super-Earths discovered by the HARPS instrument on the 3.6-metre telescope at ESO’s La Silla Observatory. This planet is about 3.6 times as massive as the Earth lis at the edge of the habitable zone around the star, where liquid water, and perhaps even life, could potentially exist. Credit: ESO

We know a ton about the inside of Earth. We know it has both an inner core and an outer core and that the churning and rotation create a protective magnetosphere that shields life from the Sun’s radiative power. It has a mantle, primarily solid but also home to magma. We know it has a crust, where we live, and plate tectonics that moves the continents around like playthings.

But what about Super-Earths? We know they’re out there; we’ve found them. What do we know about their insides? Earth’s structure, and its ability to support life, are shaped by the extreme pressure and density in its interior. The pressure and temperature inside Super-Earths are even more powerful. How does it shape these planets and affect their habitability?

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A Mars Meteorite Shows Evidence of a Massive Impact Billions of Years ago

This artist’s impression shows how Mars may have looked about four billion years ago. The young planet Mars would have had enough water to cover its entire surface in a liquid layer about 140 metres deep, but it is more likely that the liquid would have pooled to form an ocean occupying almost half of Mars’s northern hemisphere, and in some regions reaching depths greater than 1.6 kilometres. Credit: ESO/M. Kornmesser

Researchers at Australia’s Curtin University have discovered evidence of a massive impact on the Martian surface after 4.45 billion years ago. This may not seem like a surprising revelation – after all, we know that there were several large impacts on Mars, like Hellas and Argyre, and we know that large impacts happened frequently in the early solar system – so why is this a big deal?

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