Bright cometary outbursts, such as those seen in Halley's and Hale-Bopp comets have beguiled Earth-based observers for tens of thousands of years. But planetary scientists have long wondered how so-called Jupiter Family Comets (JFCs), such as Tempel 1, Wild 2, and 67P/Churyumov-Gerasimenko, continually replenish their populations and end up on short-term orbits in the inner solar system.
In a paper just published in The Astrophysical Journal Letters , a team of researchers report the discovery of an orbital region just beyond Jupiter that acts as a "comet gateway," the University of Arizona at Tucson notes. The idea is that this donut-shaped gateway gravitationally funnels icy bodies called centaurs into our inner solar system.
Although they are ultimately thought to originate in the outer solar system's Kuiper Belt, Neptune appears to nudge these centaurs inward. Thus, as the university reports, they appear to be the source population of roughly 1,000 short-period comets that ply their way through our inner solar system.
Other things to check out:
The solar system has too many moons – it's time for a cull | New Scientist
OK, WHAT I’m about to say may cause some distress. You remember how it was with Pluto? In 2006 , the International Astronomical Union (IAU) voted to downgrade the much-loved ninth planet to a mere dwarf planet . More than a decade later , it seems some people still haven’t gotten over it. But I’m still going to say it: things are getting a little out of hand with the solar system’s moons.
On 7 October, astronomers announced the discovery of 20 moons around Saturn . This took the total number of moons in the solar system to 214. The …
This potential moon outside of the solar system isn't anything like ours - CNN
(CNN) In October 2018, astronomers discovered what they thought could be an exomoon, a moon outside our solar system! New-Found Comet Gateway Funnels Icy Bodies Into Inner ...sciencestreets.com/news/ ...into-inner...In a paper just published in The Astrophysical Journal Letters, a team of researchers report the discovery of an orbital region just beyond Jupiter that acts as a " comet gateway ," the University of Arizona at Tucson notes. The idea is that this donut-shaped gateway gravitationally funnels icy bodies called centaurs into our inner solar system.!! The exomoon, which is estimated to be the size of Neptune, was found in orbit around a gigantic gas planet 8,000 light years from Earth.
Earth Is Not Unique: New Technique Using Ancient Stars Studies Geochemistry of Planets Outside
“We have just raised the probability that many rocky planets are like the Earth, and there’s a very large number of rocky planets in the universe,” said co-author Edward Young, UCLA professor of geochemistry and cosmochemistry.
“We’re studying geochemistry in rocks from other stars, which is almost unheard of,” Young said.
“Learning the composition of planets outside our solar system is very difficult,” said co-author Hilke Schlichting, UCLA associate professor of astrophysics and planetary science. “We used the only method possible — a method we pioneered — to determine the geochemistry of rocks outside of the solar system.”
White dwarf stars are dense, burned-out remnants of normal stars. Their strong gravitational pull causes heavy elements like carbon, oxygen, and nitrogen to sink rapidly into their interiors, where the heavy elements cannot be detected by telescopes! Newfound Cosmic 'Gateway' Funnels Small, Icy Objects to ...gateway - ...icy ...Newfound Cosmic ' Gateway ' Funnels Small, Icy Objects to the Inner Solar System Hamilton County Weather September 24, 2019 Beginning as small, icy bodies on the outskirts of the solar system, comets turn into spectacular streaks of light when they pass through a " gateway " near Jupiter, according to new research.!! The closest white dwarf star Doyle studied is about 200 light-years from Earth and the farthest is 665 light-years away.
And here's another article:
Solar systems are 'baby-proof' for newborn planets - CNN
A Faux Saturn Moon Titan on Earth Could Solve Solar System Mystery | Space
Big, schmancy compounds keep popping up all over the solar system , and new research may help clear up confusion about how they form in so many places.
"These dunes are pretty large," study senior author Ralf Kaiser, a chemist at the University of Hawaii at Manoa, told Space.com, nearly as tall as the Great Pyramid in Egypt, he added. "If you want to understand the carbon and hydrocarbon cycle and the processes of hydrocarbons on Titan, it's really important to understand, of course, where the dominant source of carbon comes from."
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On Titan, there's a straightforward mechanism that scientists know likely builds polycyclic aromatic hydrocarbons: These large molecules can form in the moon's thick atmosphere and settle down to the surface! Newfound Cosmic "Gateway" funnels small, icy objects to ...gateway - ...to-the...Ancient pyramid found on Aegean island reveals beginnings of ancient Greek civilisation!! But the same family of compounds has been found on plenty of worlds that boast no such atmosphere, like the dwarf planets Pluto and Ceres and the Kuiper Belt object Makemake .
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