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Did early Earth spin on its side?

1 November 2016 Astronomy Now

New theoretical modelling of the ancient history of the Earth and the Moon suggests that the giant collision that spawned our natural satellite may have left Earth spinning very fast, and with its spin axis highly tilted. The simulations give new insight into the question of whether planets with big moons are more likely to have moderate climates and life.

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NOAA satellite shows Moon crossing face of Earth for second time in a year

12 July 2016 Astronomy Now

On 5 July 2016, the Moon passed between the National Oceanic and Atmospheric Administration’s DSCOVR satellite and Earth. NASA’s EPIC camera aboard DSCOVR snapped these images over a period of about four hours. In this set, the far side of the Moon, which is never seen from Earth, passes by. The last time EPIC captured this event was 16-17 July 2015.

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Climate change creates wobbles in Earth’s spin axis

11 April 2016 Astronomy Now

Earth does not always spin on an axis running through its poles. Instead, it wobbles irregularly over time, currently drifting toward the British Isles at 17cm per year. These wobbles don’t affect our daily life, but they must be taken into account to get accurate results from GPS, satellites and observatories on the ground.

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Moon thought to play major role in maintaining Earth’s magnetic field

1 April 2016 Astronomy Now

The Earth’s magnetic field is produced by the geodynamo, the rapid motion of huge quantities of liquid iron alloy in the Earth’s outer core. A team of French researchers suggests that elastic deformation of our planet’s mantle due to tidal effects caused by the Moon — overlooked until now — transfers energy to the Earth’s outer core, keeping the geodynamo active.

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Ancient lunar polar ice reveals tilting of Moon’s axis

23 March 2016 Astronomy Now

Did the “Man in the Moon” look different from ancient Earth? New NASA-funded research provides evidence that the spin axis of the Moon shifted by about five degrees roughly three billion years ago. The evidence of this motion is recorded in the distribution of ancient lunar ice, evidence of delivery of water to the early solar system.

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Moon was produced by head-on collision between Earth and forming planet

29 January 2016 Astronomy Now

The Moon was formed by a violent, head-on collision between the early Earth and a “planetary embryo” called Theia (pronounced THAY-eh) approximately 100 million years after the Earth formed, UCLA scientists reveal. This new research also refutes the work of a team of German scientists who, in 2014, reported that the Moon also has its own unique ratio of oxygen isotopes, different from Earth’s.

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NASA’s Van Allen probes revolutionise view of radiation belts

20 January 2016 Astronomy Now

About 600 miles from Earth’s surface is the first of two doughnut-shaped electron swarms, known as the Van Allen Belts. Understanding the shape and size of the belts, which can shrink and swell in response to incoming radiation from the Sun, is crucial for protecting technology in space. A new study of data from NASA’s Van Allen Probes reveals that the story is a complex one.