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Scientists improve brown dwarf weather forecasts

17 August 2017 Astronomy Now

Dim objects called brown dwarfs, less massive than the Sun but more massive than Jupiter, have powerful winds and clouds — specifically, hot patchy clouds made of iron droplets and silicate dust. Scientists recently realised these giant clouds can move and thicken or thin surprisingly rapidly, in less than an Earth day, but did not understand why.

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NASA counts down final month of Cassini’s tour of Saturn

15 August 2017 Stephen Clark

NASA’s Cassini orbiter sailed through the tenuous outermost reaches of Saturn’s atmosphere without trouble Monday, performing the first of five close swings nearer to the planet than any previous spacecraft before a final dive Sept. 15 to end the probe’s nearly 20-year mission.

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TRAPPIST-1 is older than our Solar System

15 August 2017 Astronomy Now

Scientists now have a good estimate for the age of one of the most intriguing planetary systems discovered to date — TRAPPIST-1, a system of seven Earth-size worlds orbiting an ultra-cool dwarf star about 40 light-years away. Researchers say in a new study that the TRAPPIST-1 star is quite old: between 5.4 and 9.8 billion years. This is up to twice as old as our own Solar System, which formed some 4.5 billion years ago.

Picture This

Haze on Saturn’s horizon

27 July 2017 Astronomy Now

This false-color view from NASA’s Cassini spacecraft gazes toward the rings beyond Saturn’s sunlit horizon. Along the limb at left can be seen a thin, detached haze. This haze vanishes toward the left side of the scene.