Ice Deposits on Ceres Might Only Be a Few Thousand Years Old

NASA's Dawn spacecraft captured this approximately true-color image of Ceres in 2015 as it approached the dwarf planet. Dawn showed that some polar craters on Ceres hold ancient ice, but new research suggests the ice is much younger. Image Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA / Justin Cowart

The dwarf planet Ceres has some permanently dark craters that hold ice. Astronomers thought the ice was ancient when they were discovered, like in the moon’s permanently shadowed regions. But something was puzzling.

Why did some of these shadowed craters hold ice while others did not?

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If Europa has Geysers, They’re Very Faint

Jupiter's second Galilean moon, Europa. Its smooth surface has fewer craters than other moons, but they help us understand its icy shell. (Credit: NASA/JPL/Galileo spacecraft)
The Hubble spotted evidence of geysers coming from Jupiter's moon Europa, but nobody's been able to find them again. (Credit: NASA/JPL/Galileo spacecraft)

In 2013, the Hubble Space Telescope spotted water vapour on Jupiter’s moon Europa. The vapour was evidence of plumes similar to the ones on Saturn’s moon Enceladus. That, and other compelling evidence, showed that the moon has an ocean. That led to speculation that the ocean could harbour life.

But the ocean is obscured under a thick, global layer of ice, making the plumes our only way of examining the ocean. The plumes are so difficult to detect they haven’t been confirmed.

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Curiosity has Reached an Ancient Debris Channel That Could Have Been Formed by Water

The steep path NASA’s Curiosity Mars rover took to reach Gediz Vallis channel is indicated in yellow in this visualization made with orbital data. At lower right is the point where the rover veered off to get an up-close look at a ridge formed long ago by debris flows from higher up on Mount Sharp. NASA/JPL-Caltech/UC Berkeley

Like a pilgrim seeking wisdom, NASA’s MSL Curiosity has been working its way up Mt. Sharp, the dominant central feature in Gale Crater. Now, almost 12 years into its mission, the capable rover has reached an interesting feature that could tell them more about Mars and its watery history. It’s called the Gediz Vallis channel.

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Mars’ Gale Crater was Filled with Water for Much Longer Than Anyone Thought

Layers at the base of Mt. Sharp. These visible layers in Gale Crater show the chapters of the geological history of Mars in this image from NASA's Curiosity rover. New evidence from this area shows that water persisted on Mars for longer than thought. Credit: NASA/JPL-Caltech/MSSS.

Even with all we’ve learned about Mars in recent years, it doesn’t stack up against all we still don’t know and all we hope to find out. We know that Mars was once warm and wet, a conclusion that was less certain a couple of decades ago. Now, scientists are working on uncovering the details of Mars’s ancient water.

New research shows that the Gale Crater, the landing spot for NASA’s MSL Curiosity, held water for a longer time than scientists thought.

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How Warm Are the Oceans on the Icy Moons? The Ice Thickness Provides a Clue.

Jupiter's moon Ganymede is the largest moon in the Solar System and may have an ocean sandwiched between two layers of ice. But how warm is that ocean? Image Credit: By National Oceanic and Atmospheric Administration Public Domain, https://commons.wikimedia.org/w/index.php?curid=8070396

Scientists are discovering that more and more Solar System objects have warm oceans under icy shells. The moons Enceladus and Europa are the two most well-known, and others like Ganymede and Callisto probably have them too. Even the dwarf planet Ceres might have an ocean. But can any of them support life? That partly depends on the water temperature, which strongly influences the chemistry.

We’re likely to visit Europa in the coming years and find out for ourselves how warm its ocean is. Others on the list we may never visit. But we may not have to.

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This Planet-Forming Disk has More Water Than Earth’s Oceans

Astronomers have found water vapour in a disc around a young star exactly where planets may be forming. In this image, the new observations from the Atacama Large Millimeter/submillimeter Array (ALMA) show the water vapour in shades of blue. Image Credit: ALMA (ESO/NAOJ/NRAO)/S. Facchini et al.

Astronomers have detected a large amount of water vapour in the protoplanetary disk around a young star. There’s at least three times as much water among the dust as there is in all of Earth’s oceans combined. And it’s not spread throughout the disk; it’s concentrated in the inner disk region.

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Water Found on the Surface of an Asteroid

Courtesy of NASA/Carla Thomas/SwRI Using data from NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), Southwest Research Institute scientists have discovered, for the first time, water molecules on the surface of an asteroid. Scientists looked at four silicate-rich asteroids using the FORCAST instrument to isolate the mid-infrared spectral signatures indicative of molecular water on two of them.

Our Solar System is a collection of objects from planets and moons to comets and asteroids. It’s thought there are upwards of 1 million asteroids orbiting the Sun and it was thought that any water present on them should have evaporate long ago. A recent study using data from the SOFIA infrared telescope discovered water on the asteroids Iris and Massalia. 

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Thirsty? Water is More Common than you Think

Artist rendition of a potential water-world exoplanet that might support advanced civilizations. Such life could advertise its existence via technosignatures from industrial or other activities. (Credit: ESA / Hubble / M. Kornmesser)
Artist rendition of a potential water-world exoplanet that might support life. Scientists could determine whether to explore this world based on its planetary entropy production. (Credit: ESA / Hubble / M. Kornmesser)

Water is the most common chemical molecule found throughout the entire universe. What water has going for it is that its constituents, hydrogen and oxygen, are also ridiculously common, and those two elements really enjoying bonding with each other. Oxygen has two open slots in its outmost electron orbital shell, making it very eager to find new friends, and each hydrogen comes with one spare electron, so the triple-bonding is a cinch.

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Early Mars Climate was Complex, with Streams Flowing Intermittently for Millions of Years

This figure from new research shows an unnamed river valley network on Mars. By dating the craters in the image, a researcher at the Planetary Science Institute was able to determine when the river channels were formed. Image Credit: MOLA MEGDR, NASA/USGS; THEMIS mosaic, ASU/NASA/USGS; CTX, NASA/MSSS.

There’s overwhelming evidence that Mars was once wet and warm. Rivers flowed across its surface and carved intricate channel systems revealed by our orbiters. Expansive oceans even larger than Earth’s may have covered a third of its surface. Then something happened: Mars lost its atmosphere, cooled down, and surface water disappeared.

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Is K2-18b Covered in Oceans of Water or Oceans of Lava?

This illustration shows what exoplanet K2-18 b could look like based on science data. NASA’s James Webb Space Telescope examined the exoplanet and revealed the presence of carbon-bearing molecules. The abundance of methane and carbon dioxide, and shortage of ammonia, support the hypothesis that there may be a water ocean underneath a hydrogen-rich atmosphere in K2-18 b. But more extensive observations with the JWST are needed to understand its atmosphere with greater confidence. Image Credit: By Illustration: NASA, ESA, CSA, Joseph Olmsted (STScI)Science: Nikku Madhusudhan (IoA)

In the search for potentially life-supporting exoplanets, liquid water is the key indicator. Life on Earth requires liquid water, and scientists strongly believe the same is true elsewhere. But from a great distance, it’s difficult to tell what worlds have oceans of water. Some of them can have lava oceans instead, and getting the two confused is a barrier to understanding exoplanets, water, and habitability more clearly.

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