A model that needs fewest parameters to explain a scenario is favourable. The fact that mm-size dust grains (chondrules) are present in the entire solar system brings rise to the question, whether all bigger solid objects are a collection of chondrules.
How and where did the first organic molecules emerge? Sophisticated chemistry models for the synthesis of amino acids within planetesimals can help us to decipher these mysteries.
Pluto: the last and final of the ‘original’ 9 planets of the Solar System to be visited by a probe. NASA’s New Horizons arrived at this tiny world at the edge of the Solar System earlier this week bringing into sharp focus for the first time. Science was a plentiful from every new image that was released, so here’s a quick recap for you, just in case you blinked and missed it…
Among the many ideas proposed to explain the formation of our Solar system, one of the leading theories is the “Grand Tack”. This scenario suggests that, early in their formation, Jupiter and Saturn undertook a sweeping voyage, migrating from the outer Solar System to within the orbit of Mars. The two huge planets then entered an orbital resonance with each other, before their cosmic dance took them back out to their current positions. The model neatly explains, amongst other things, the current locations of Mars, the Asteroid Belt and the outer planets—which are hard to recreate in models assuming a more static Solar System.
Planets seem to occur all over the place in the universe. However, it is still unknown how they form. The growth of objects larger than meter size is difficult because objects of this size quickly fall into the central star. This Astrobite gives a small overview of the meter-size barrier as found by Stuart J. Weidenschilling in 1977.
In July of this year (2015), NASA’s New Horizons mission will fly past Pluto and its moons. It will map the surface of the Plutonian system in unprecedented detail, revealing craters and other surface features for the first time. In preparation for the deluge of newly discovered craters, mountains, crevasses and other surface features, Mamajek et al. discuss a naming system for Pluto and its moons.