planetesimals tagged posts

New Horizons Team uncovers a Critical Piece of the Planetary Formation puzzle

The uniform color and composition of Arrokoth’s surface shows the Kuiper Belt object formed from a small, uniform, cloud of material in the solar nebula, rather than a mishmash of matter from more separated parts of the nebula. The former supports the idea that Arrokoth formed in a local collapse of a cloud in the solar nebula.
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko

Data from NASA’s New Horizons mission are providing new insights into how planets and planetesimals – the building blocks of the planets – were formed.

The New Horizons spacecraft flew past the ancient Kuiper Belt object Arrokoth (2014 MU69) on Jan...

Read More

Rare Metals on Mars and Earth implicate Colossal Impacts

The surface features of the northern and southern hemispheres of Mars are very different. In this topographic map, the northern hemisphere (shown in blue) is mostly smooth lowlands and has experienced extensive volcanism. The southern hemisphere (in orange) has an older, cratered highland surface. This dichotomy could have been caused by a giant impact. Credit: University of Arizona/LPL/SwRI

The surface features of the northern and southern hemispheres of Mars are very different. In this topographic map, the northern hemisphere (shown in blue) is mostly smooth lowlands and has experienced extensive volcanism. The southern hemisphere (in orange) has an older, cratered highland surface. This dichotomy could have been caused by a giant impact. Credit: University of Arizona/LPL/SwRI

New research has revealed that a giant impact on Mars more than 4 billion years ago would explain the unusual amount of “iron loving” elements in the Red Planet. Planets form as small dust grains stick together and agglomerate with other grains, leading to bigger bodies termed “planetesimals...

Read More

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

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

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