Until then, all the known exoplanets (planets circling other stars) were big and gaseous, but this one is probably made
of rocky materials — the first world like ours found in an alien solar system.
Models say that Jupiter should have captured about 70 million gigatonnes
of rocky material, but less than half that amount remains as irregular moons.
Models of Jupiter's interior suggest it has a solid core of up to 18 Earth - masses» worth
of rocky material — just about 6 percent of Jupiter's total mass.
In a protoplanetary cloud around a young star there would be tiny grains
of rocky material that would provide a surface on which chemicals could react.
«Spectroscopic observations of the white dwarf allowed us to measure the abundances
of the rocky material as it is being accreted and filtered through the star's atmosphere in real time,» Melis said.
Not exact matches
Planets that were
rocky from the start should be smaller close to the stars, where studies
of other young star systems suggest there should have been less
material available when these planets were forming.
The other suggests they arose in a two - stage process called core accretion, in which bits
of material smashed and fused together to form bigger
rocky, icy bodies.
The researchers also found that, compared with today's
rocky material, the ancient crust was composed
of much denser stuff, enriched in iron and magnesium.
What little
rocky material occurs in today's ring system probably is the debris
of collisions between icy ring particles and asteroids and comets swept up by the planet's huge gravitational field, says Canup.
The presence
of this rock at a site indicates either that
material has pushed up through Earth's crust from the mantle (a silicate
rocky shell between the crust and the core with an average thickness
of 2,886 km and depths ranging from 30 km to almost 3,000 km below the crust) or that a celestial body (a comet, meteor or meteorite) fell there.
Over the course
of about 100 million years, most
of the
material in that nebulous cloud accreted into the existing eight planets — four
rocky (including Earth) and four gaseous.
When later generations
of stars form, some
of that
material congeals into
rocky planets like Earth.
Thanks to the
material from Güéjar Sierra in Granada that Boissier analysed, it was determined that the plant was typical
of sandy substrates, often dolomitic (
rocky), and was found in the provinces
of Granada, Málaga and Jaén.
Powerful gravitational perturbations from the two stars on the
rocky building blocks
of planets lead to destructive collisions that grind down the
material.
If Pluto's core was
rocky and its mantle icy, most
of the
material blasted into space by the collision would have been ice, accounting for Pluto's high rock - to - ice ratio today.
Astronomers at the Universities
of Cambridge and Warwick say this is the first «reliable evidence» for water - rich,
rocky planetary
material in any extrasolar planetary system.
They estimate that approximately 30 percent
of the minor planet's mass was water and other ices, and approximately 70 percent was
rocky material.
By learning about the layering
of these
materials, scientists can explain why some
rocky planets turn into an «Earth» rather than a «Mars» or «Venus» — a factor that is essential to understanding where life can appear in the universe.
Building on past observations
of the white dwarf called SDSSJ1043 +0855 (the dead core
of a star that originally was a few times the mass
of the Sun), which has been known to be gobbling up
rocky material in its orbit for almost a decade, the team used Keck Observatory's HIRES instrument fitted to the 10 - meter Keck I telescope as well as data from the Hubble Space Telescope to measure and characterize the
material being accreted by the star.
In addition to extending a relatively new method
of determining the chemical composition
of planets to examine their internal structure, the team found that the
rocky material being accreted by the star could be comprised
of minerals that are typically associated with marine life processes here on Earth.
Colliding at speeds up to 22,000 miles per hour (36,000 kilometers per hour), such a collision may have stripped most
of the
rocky mantle from the protoplanet that became Mercury with its iron - rich core, while a Mars - size protoplanet struck the early Earth off - center and created a spray
of mostly mantle
material that later accreted to form the Moon.
This
material has been enriched by nuclear reactions deep within the star and includes many
of the elements necessary for forming
rocky planets like our Earth, such as silicon and magnesium, and which are also the basis for life.
Gaya Island Resort is located on Pulau Gaya, the largest
of a cluster
of five islands that form the Tunku Abdul Rahman Marine Park, a natural conservation area off the coast
of Borneo, close to Kota Kinabalu.Gaya Island Resort has a unique setting: the land is fringed with a golden sandy beach,
rocky coastal outcrops, and surrounded by coral reefs.The hilly island landscape is covered with lush tropical rainforest and an abundance
of flora and fauna.And to complete this perfect setting, visible in the distance, is the stunning outline
of Mount Kinabalu.The guest villa exterior respects Sabahan architecture, uses local
materials and blends harmoniously with the natural environment.
Henry uses torn cardboard surfaces as
material starting points for his series
of delicately - rendered, collaged drawings, and the resulting
rocky scenes are at once irrepressibly American and bewitchingly other.
He gave us much
of it, the integration
of natural
materials into the
rocky Canadian landscape.