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NASA’s Dawn spacecraft mapped dwarf planet Ceres and found evidence — a low-density region of the crust (blue) — of an underground brine reservoir. This composite image shows gravity anomalies (red is high, blue is low) on the right side and Ceres’ real colours on the left. (Anton Ermakov, UC Berkeley, NASA/JPL)
Sky News This Week: August 12, 2020

Evidence builds for Ceres’ watery underground, a Milky Way-like galaxy is found in the young universe, and Mars might be a colder planet than imagined in its early history.

Water sits underground in a small world

NASA’s Dawn spacecraft mapped dwarf planet Ceres and found evidence — a low-density region of the crust (blue) — of an underground brine reservoir. This composite image shows gravity anomalies (red is high, blue is low) on the right side and Ceres’ real colours on the left. (Anton Ermakov, UC Berkeley, NASA/JPL)

A new analysis of low-altitude data has concluded that dwarf planet Ceres has briny water lurking below its surface. The orbiting NASA Dawn spacecraft examined the underground structure of the large world in 2018 and found from gravity data indicators of a low-density region below the impact crater Occator. The measurements are consistent with a slushy zone that is full of ice water and salts. Scientists say when a meteor crashed into Ceres 20 million years ago, it was the impact that created the underground slush.

Source: University of California, Berkeley

Young Milky Way lookalike found

Astronomers have spotted a young galaxy that looks very similar to our Milky Way. The Atacama Large Millimeter/submillimeter Array peered far away in the sky, to a time when the universe was only 1.4 billion years old. The galaxy they looked at, called SPT0418-47, is “surprisingly unchaotic”, the research team says, meaning that we may have to rethink how galaxies evolved early in their history. Like our Milky Way, the galaxy has a rotating disk and a large “bulge” or group of stars at the centre of the galaxy.

Source: European Southern Observatory

Earth’s ozone could help us search for exoplanets

The venerable Hubble Space Telescope used Earth as a test run for searching for ozone on other planets. During a lunar eclipse, Hubble peered at the moon, using it as a sort of “mirror” that reflects sunlight. For the first time ever, a space telescope observed the moon in the Earth’s shadow at ultraviolet wavelengths. During this time, Hubble saw the signature of ozone, a key protector of life in the Earth’s atmosphere as it shields our planet from radiation in space. This technique could be adapted for looking for possibly habitable exoplanets.

Source: NASA

Early Mars could have been a cold place

New research suggests the young Red Planet might have been covered in ice sheets instead of warm, flowing rivers.

Researchers from Western University and the University of British Columbia compared valley networks on Mars to valley networks found in Canada’s Arctic, among other methodologies, and found that there are similarities on the Red Planet to valley networks formed on Earth under glaciation. There still would have been flowing water on Mars, but it would have been underneath thick ice sheets, and climate modelling predicts that the planet’s ancient climate was much cooler during the time of valley network formation.

There’s still hope for life on Mars, however. The study suggests a sheet of ice would lend more protection and stability of underlying water, as well as providing shelter from solar radiation.

However, some researchers maintain that Mars had a thicker atmosphere and warm surface in the past, so more study will be required.

Source: Western University

Weird, persistent cloud found in Venus’ atmosphere

The Japanese orbiter Akatsuki found a persistent cloud “feature” in the atmosphere of Venus that can sometimes stretch as far as 7,500 kilometres across the mid-latitudes of the planet. While Venus is known to have long-lasting clouds in its atmosphere, this newly found feature could be linked to another poorly understood thing about the planet: why its upper atmosphere rotates so much more quickly than the planet itself. It is thought this large feature could affect the workings of the atmosphere at different altitudes.

Sources: Japanese Aerospace Exploration Agency, Portugal’s Institute of Astrophysics and Space Sciences

Elizabeth Howell (Ph.D.) is a Canadian space journalist who has been obsessed with the topic ever since she, as a young teenager, saw the movie Apollo 13 in 1996. She grew up wanting to be an astronaut. While that hasn’t happened (yet), Elizabeth has seen five human spaceflight launches — including two from Kazakhstan — and she participated in a simulated Red Planet mission at the Mars Society’s Mars Desert Research Station in Utah.

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