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The changing colours of Saturn’s north pole

25 October 2016 Astronomy Now

Scientists are investigating potential causes for the change in colour of the region inside the north-polar hexagon on Saturn, thought to be an effect of the planet’s seasons. In particular, the change to a more golden hue may be due to the increased production of photochemical hazes in the atmosphere as the north pole approaches summer solstice in May 2017.

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Low-mass star simulations favour water-rich, Earth-sized planets

24 October 2016 Astronomy Now

Astrophysicists at the University of Bern conducting computer simulations of the formation of planets orbiting in the habitable zone of low-mass stars, such as the red dwarf Proxima Centauri, show that these planets are most likely to be roughly the size of the Earth and to contain large amounts of water.

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Hubble reveals NGC 362, a young globular cluster

24 October 2016 Astronomy Now

Globular clusters offer some of the most spectacular sights in the night sky. These ornate spheres contain hundreds of thousands of stars, and reside in the outskirts of galaxies. The Milky Way contains over 150 such clusters — and the example shown in this NASA/ESA Hubble Space Telescope image, named NGC 362, is one of the most unusual ones.

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How to find Ceres, the nearest and brightest dwarf planet at its best

23 October 2016 Ade Ashford

Ceres, the largest minor planet inside the orbit of Neptune, passed closest to Earth on the evening of 22 October — the night of the last quarter Moon. With the lunar crescent now confined to the morning sky, grab your binoculars or telescope, print out some star charts from our online guide and track down the brightest of the dwarf planets while at its best.

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Oldest known planet-forming circumstellar disc discovered

22 October 2016 Astronomy Now

A group of citizen scientists and professional astronomers joined forces to discover an unusual hunting ground for exoplanets. They found a red dwarf, called AWI0005x3s, surrounded by the oldest known circumstellar disc — a 45-million-year-old primordial ring of gas and dust orbiting the star from which planets can form.

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The universe is expanding at an accelerating rate — or is it?

21 October 2016 Astronomy Now

Five years ago, the Nobel Prize in Physics was awarded to three astronomers for their discovery, in the late 1990s, that the universe is expanding at an accelerating pace. Now, a team of scientists led by Professor Subir Sarkar of Oxford University’s Department of Physics has cast doubt on this standard cosmological concept.

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Unexpected discoveries on a metal world

21 October 2016 Astronomy Now

Astronomers have discovered possible evidence for water on the surface of 16 Psyche, the largest metallic asteroid in the solar system. Measuring 186 miles across and consisting of almost pure nickel-iron metal, Psyche is thought to be the remnant core of a planetary embryo that was mostly destroyed by impacts billions of years ago.