Sentences with phrase «of planetesimal»

The survey allows us to address some qu... ▽ More Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems.

Abstract: Cool debris discs are a relic of the planetesimal formation process around their host star, analogous to the solar system's Edgeworth - Kuiper belt.

The survey allows us to address some questions related to the prevalence and properties of planetesimal systems.

The full sample of 177 FGK stars with d < 20 pc proposed for the DUNES su... ▽ More Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems.

Models of planetesimal dispersion predict that roughly 10 times as many objects wound up in the Oort Cloud as in the scattered disk, according to the new study.

These findings lend credence to the fast - pebble - collapse theory of planetesimal formation, says Joseph Masiero, an astronomer at NASA's Jet Propulsion Lab in Pasadena, Calif., who was not involved in the work.

Some of these planetesimals became the embryonic forms of the planets in our solar system today, the Earth being one of them.

This finding, reported online August 3 in Science, may help resolve a long - standing debate over the origins of planetesimals — the giant space rocks that populated the...

Enough grist to form a massive ring could have only been supplied billions of years ago, when the early solar system was chock full of planetesimals.

Any known dust production caused by collisions of planetesimals should diminish over time, as the number of planetesimals is reduced as they are destroyed.

Terrestrial planet formation models indicate Earth went through a sequence of major growth phases: accretion of planetesimals and planetary embryos over many tens of millions of years; a giant impact that led to the formation of our Moon; and then the late bombardment, when giant asteroids, dwarfing the one that presumably killed the dinosaurs, periodically hit ancient Earth.

Fragments of these planetesimals remain today as meteorites called achondrites, which scientists have pored over for clues to how planets formed.

Henny Lamers of the University of Utrecht in the Netherlands, says that the variations in brightness could also have been caused by a dense cloud of planetesimals, the small building blocks from which fully fledged planets are thought to accumulate.

But until then we have a handful of roughly Pluto - sized objects residing in the Kuiper belt that stand out amongst the sea of the planetesimals residing beyond Neptune.

This serves to increase the capture rate of the planetesimals by a factor of ten.

It's therefore thought that the solar system lost a lot of planetesimals in its formative years, and asteroids would have been slingshot and ejected into interstellar space.

However, recent observations have confirmed the presence of a non-negligible amount of cold gas in the circumstellar (CS) debris discs around young main - sequence stars.This cold gas has been suggested to be related to the outgassing of planetesimals and cometary - like objects.

The majority of these systems are unresolved and analysis of the dust properties is limited by the lack of information regarding the dust location.vThe Herschel DUNES key program is observing 133 nearby, Sun - like stars (< 20 pc, FGK spectral type) in a volume... ▽ More Dusty debris discs around main sequence stars are thought to be the result of continuous collisional grinding of planetesimals in the system.

A low dynamical excitation of the planetesimals with eccentricities up to 0.03 is preferred.

Abstract: Dusty debris discs around main sequence stars are thought to be the result of continuous collisional grinding of planetesimals in the system.

The team finds that including more realistic starting conditions (a larger number of planetesimals and planetesimals with higher ice content) than usually assumed, red dwarf planets will not be dry.

Not exact matches

Re: phosphorus in meteorites Any so - called theory about conditions 3.5 billion years ago had better integrate the collision with the planetesimal that gave rise to our Moon and what that means in terms of elements, geological processes, and so forth.

The gravitational forces of these spiral arms could scatter outward the problematic boulder - sized bodies, allowing them to accumulate rapidly to form planetesimals large enough that gas drag is no longer a problem.

Identification of a primordial asteroid family constrains the original planetesimals population.

The discs around these stars contain gas, dust, and planetesimals — the building blocks of planets and the progenitors of planetary systems.

The second idea argues that swarms of centimeter - sized pebbles almost instantaneously collapsed under their collective weight to create planetesimals hundreds of kilometers across.

The fact that none were just a few kilometers across undercuts the any - size - goes theory of gradual planetesimal formation, Walsh and colleagues argue.

Moulton, an astronomer from the University of Chicago known for the planetesimal theory of planet formation, served as AAAS Permanent Secretary and then Administrative Secretary, 1937 to 1948.

The incredibly diverse mix of molecules and particles that we call air has a history stretching back to 4.5 billion years ago, when space rocks and planetesimals bombarded the still - forming Earth.

Wood deduced how much gold ought to be present in Earth's crust by comparing the crust's composition to that of meteorites similar to the planetesimals.

Earth formed from a series of smaller planetesimals that crashed together over the course of 30 million to 40 million years.

That's compelling evidence for the gravitational collapse theory of asteroid formation, which states that the space dust that made up the planetesimals smashed together almost instantaneously.

By aggregating the sizes of the modern dark asteroids, researchers suggest the original dark planetesimals formed about 4 billion years ago, making this one of the oldest asteroid families in the main belt; most asteroid families are thought to have formed about 1 billion years ago.

Piecing together the planetesimals, the earliest ancestors of the asteroids, hasn't been easy because eons of collisions have broken them apart.

«Many of them look like what might be erupting on Hawaii, but they cooled on a very early planetesimal.»

In contrast to earlier observations the team did not observe dust that will later form into planets, but dust created in collisions between small planets of a few kilometres in size — objects called planetesimals that are similar to the asteroids and comets of the Solar System.

But at the same time, Mars is nudged outward by trillions of close encounters with planetesimals that give infinitesimal gravitational kicks to the growing Mars without hitting it.

The resulting paper, «Identification of a primordial asteroid family constrains the original planetesimal population,» appears in the August 3, 2017, online edition of Science.

An inward - migrating Jupiter would have flung planetesimals out of the way to clear a gap.

Dr Michele Bannister said: «We've discovered that this is a planetesimal with a well - baked crust that looks a lot like the tiniest worlds in the outer regions of our solar system, has a greyish / red surface and is highly elongated, probably about the size and shape of the Gherkin skyscraper in London.

This is GPI imaging polarimetry of the circumstellar disk around HR 4796A, a ring of dust and planetesimals similar in some ways to a scaled up version of the solar system's Kuiper Belt.

The planetesimals, which eventually merged to form the rocky planets, were more planetlike than previously thought, with cores that must have formed and melted within just a few million years of the formation of the solar system, Weiss says.

Although most asteroids now are rocky through and through, the new findings suggest that back at the beginning of the solar system even planetesimals could melt at their cores and retain a rocky crust.

Oddly, the meteorites are magnetic, which is strange because the planetesimals were supposed to be just large agglomerations of rubble.

In this case, the sudden drop would be caused by the central part of the cloud passing in front of the star; the brightening before and afterwards could be explained by starlight being scattered in our direction by dust in the planetesimal cloud.

The processes that convert these tiny grains, each a few millionths of a metre (a micron) across, into aggregates a few centimetres in size, and the mechanism for making kilometre - sized «planetesimals» into planetary cores, are both well understood.

The Kuiper Belt hosts a swarm of distant, icy objects ranging in size from small, primordial planetesimals to much larger, highly evolved objects, representing a whole new class of previously unexplored cryogenic worlds.

Swarms of boulder - size objects called planetesimals slowly accreted to form the rocky planets — Mercury, Venus, Earth, and Mars — and their various and sundry satellites.

GPI imaging polarimetry of the circumstellar disk around HR 4796A, a ring of dust and planetesimals similar in some ways to a scaled up version of the solar system's Kuiper Belt.

I study the early stages of planet formation, where microscopic dust particles coagulate to form planetesimal - size bodies.