Astronomers believe that planets form like snowballs over millions of years, as
small dust grains clump together to form larger bodies.
I apply numerical models to investigate the physical and chemical evolution of planetary materials, ranging from
the small dust grains suspended in protoplanetary disks to the many kilometer - scale objects which accrete together to form planets.
Galileo has also found that Jupiter's rings are made of
small dust grains blasted off the surface of Jupiter's four innermost satellites by the impacts of meteoroids.
Small dust grains can grow as they collide and stick together with static electricity.
Not exact matches
Wireless powered implants, each
smaller than a
grain of rice, could serve as «neural
dust» that can one day scan and stimulate brain cells.
12 sea scallops Salt and pepper 1 clove garlic, minced All - purpose flour for
dusting 2 tablespoons white or medium miso paste 1 tablespoon mirin 1 teaspoon soy sauce 1 teaspoon superfine sugar
Small bunch watercress, thick stems removed 2 tablespoons vegetable oil 2 tablespoons dry white wine 1/2 tablespoon whole
grain mustard 2 tablespoons heavy cream 1/4 cup finely grated Parmesan cheese.
The particles of rock and ice in these belts vary in size from the tiniest
dust grain,
smaller than a millimetre across, up to asteroid - like bodies many kilometres in diameter [2].
Earlier, in 2000 and 2002, the craft positioned aerogel collectors on the opposite side of the arm to snare particles of interstellar
dust, suspected to be as
small as one - tenth the size of comet
grains.
Princeton astrophysicist Bruce Draine estimates that the
small spacecraft would sustain about a million collisions per square centimeter with
dust grains during the journey — each one potentially a disaster at those speeds.
Yet the very
small size of
grains on the surface of Phobos and Deimos can not, according to the researchers, be solely explained as the consequence of erosion from bombardment by interplanetary
dust.
From this light signature they deduced that the satellites are made of fine -
grained dust (
smaller than a micrometer [3]-RRB-.
This suggests a way that very
small samples (a few tens of microscopic
grains) can reveal big information about the pathways and effects of long - distance airborne
dust.
Careful analysis of the polarisation results revealed these
grains of
dust to be comparatively large particles, 0.5 micrometres across, which may seem
small, but
grains of this size are about 50 times larger than the
dust normally found in interstellar space.
The same force can push
dust into highly eccentric orbits, and even blow some of the
smaller grains out of the disk entirely.
The walk out to Pluto, a speck of
dust ten times
smaller than our sand -
grain Earth, would be nearly a half - kilometer, and along the way you'd be lucky to encounter any of the planets: Even the largest, Jupiter, would be no bigger than a
small marble.
This might indicate that
smaller (and warmer)
dust grains are responsible for the 100 μm emission than at the longer wavelengths, in agreement with the theoretical predictions of van Marle et al. (2011).
In 1983, an orbiting satellite called IRAS discovered far more infrared radiation — which has waves longer than red light — coming from the Vega than expected for
small interstellar
dust grains found around young, early - type stars (Harvey et al, 1984).
Alternatively, turbulence or charging effects might lead to a reservoir of
small grains at the surface layer that is not affected by the
dust growth and fragmentation cycle dominating the dense disk midplane.
The pile - up of millimeter
grains in a
dust trap and the continuous distribution of
small grains throughout the gap likely require a more efficient
dust fragmentation and
dust diffusion in the
dust trap.
Some are as
small as molecules; in fact, there is a borderline area in which you can think of them as very tiny
dust grains or as very large molecules.
If located within a few AUs of the central star, this
dust is warmed to temperatures that produce near - infrared emission and
small grains produce scattered light.
A good fit to the data is found by two distinct
dust populations: (1) very
small, hence unbound, hot
dust grains confined in a narrow region at the sublimation rim of carbonaceous material; (2) bound
grains at 2 AU that are protected from sublimation and have a higher mass despite their fainter flux level.
Comets might form by combining
smaller ice particles, including ice condensed as frost on microscopic
dust grains that somehow formed.
Cosmic
dust is mainly composed of silicon, carbon and aluminium, in
grains as
small as a millionth of a centimeter across.
We propose that the hot
dust is produced by the release of
small carbon
grains following the disruption of aggregates that originate from the warm component.
However, high - quality,
dust - free, clay litters are relatively
small -
grained and may be perfectly acceptable to your cat.
Most cats prefer fine -
grained, soft substrates for elimination, so the clumping litters or
dust - free
small grained clay litters are most acceptable.
Other popular characteristics are
dust free
small grain clay and clumping litters (most popular type).