Recent Comments

    planetesimals tagged posts

    Astronomers find orbit of Mars Hosts remains of Ancient Mini-Planets

    April 4, 2017, Categories  Astronomy/Space

    Left: The paths traced by the known Martian Trojans around L4 or L5 (crosses) relative to Mars (red disk) and the Sun (yellow disk). The dotted circle indicates the average Sun-Mars distance. Right: Enlargement of inset (dashed rectangle) showing the paths of the 8 L5 Trojans: 1998 VF31 (marked as "VF31" - blue), Eureka (red) and the 6 objects identified as family members (amber). The filled disks indicate the relative sizes of the asteroids. Eureka, the largest member, is about 2 km across. Credit: Apostolos Christou

    Left: The paths traced by the known Martian Trojans around L4 or L5 (crosses) relative to Mars (red disk) and the Sun (yellow disk). The dotted circle indicates the average Sun-Mars distance. Right: Enlargement of inset (dashed rectangle) showing the paths of the 8 L5 Trojans: 1998 VF31 (marked as “VF31” – blue), Eureka (red) and the 6 objects identified as family members (amber). The filled disks indicate the relative sizes of the asteroids. Eureka, the largest member, is about 2 km across. Credit: Apostolos Christou

    Mars shares its orbit with the Trojans, a handful of small asteroids. Now an international team using the Very Large Telescope have found that most of these objects share a common composition; they are likely the remains of a mini-planet destroyed by a collision long ago...

    Read More

    Spontaneous ‘Dust Traps:’ Astronomers discover a missing link in planet formation

    March 1, 2017, Categories  Astronomy/Space

    1. Stages of the formation mechanism for dust traps. The central star is depicted as yellow, surrounded by the protoplanetary disk, here shown in blue. The dust grains make up the band running through the disk. In the first stage, the dust grains grown in size, and move inwards towards the central star. The now pebble-sized larger grains (in the second panel) then pile up and slow down, and in the third stage the gas is pushed outwards by the back-reaction, creating regions where dust accumulates, the so-called dust traps. The traps then allow the pebbles to aggregate to form planetesimals, and eventually planet-sized worlds. Credit: © Volker Schurbert. Click for a full size image 2. An image of a protoplanetary disk, made using results from the new model, after the formation of a spontaneous dust trap, visible as a bright dust ring. Gas is depicted in blue and dust in red. Credit: Jean-Francois Gonzalez. Click for a full size image

    1. Stages of the formation mechanism for dust traps. The central star is depicted as yellow, surrounded by the protoplanetary disk, here shown in blue. The dust grains make up the band running through the disk. In the first stage, the dust grains grown in size, and move inwards towards the central star. The now pebble-sized larger grains (in the second panel) then pile up and slow down, and in the third stage the gas is pushed outwards by the back-reaction, creating regions where dust accumulates, the so-called dust traps. The traps then allow the pebbles to aggregate to form planetesimals, and eventually planet-sized worlds. Credit: © Volker Schurbert. Click for a full size image
    2...

    Read More