New Super Highway Network Duiscovered in the Solar System, Faster Travel Now Possible

Researchers have discovered a new superhighway network to travel through the Solar System much faster than was previously possible. Such routes can drive comets and asteroids near Jupiter to Neptune's distance in under a decade and to 100 astronomical units in less than a century. They could be used to send spacecraft to the far reaches of our planetary system relatively fast, and to monitor and understand near-Earth objects that might collide with our planet. 

In their paper, published in the Nov. 25 issue of Science Advances, the researchers observed the dynamical structure of these routes, forming a connected series of arches inside what’s known as space manifolds that extend from the asteroid belt to Uranus and beyond. This newly discovered "œcelestial autobahn," or œcelestial highway, acts over several decades, as opposed to the hundreds of thousands or millions of years that usually characterize Solar System dynamics.

The most conspicuous arch structures are linked to Jupiter and the strong gravitational forces it exerts. The population of Jupiter-family comets (comets having orbital periods of 20 years) as well as small-size solar system bodies known as Centaurs, are controlled by such manifolds on unprecedented time scales. Some of these bodies will end up colliding with Jupiter or being ejected from the Solar System.

The structures were resolved by gathering numerical data about millions of orbits in our Solar System and computing how these orbits fit within already-known space manifolds. The results need to be studied further, both to determine how they could be used by spacecraft, or how such manifolds behave in the vicinity of the Earth, controlling the asteroid and meteorite encounters, as well as the growing population of artificial man-made objects in the Earth-Moon system.

Contacts and sources: 

Ioana Patringenaru

University of California - San Diego

Source:https://www.ineffableisland.com/

Read More........→December 12, 2020

Oceans in Outer Solar System on Pluto and Large Kuiper Belt Objects, Slowly Freezing Over Time

Credit of NASA, ESA, and A. Feild (STScI)

A new study suggests that Pluto and other large Kuiper belt objects started out with liquid oceans which have been slowly freezing over time.

The accretion of new material during Pluto’s formation may have generated enough heat to create a liquid ocean that has persisted beneath an icy crust to the present day, despite the dwarf planet’s orbit far from the sun in the cold outer reaches of the solar system.

This “hot start” scenario, presented in a paper published June 22 in Nature Geoscience, contrasts with the traditional view of Pluto’s origins as a ball of frozen ice and rock in which radioactive decay could have eventually generated enough heat to melt the ice and form a subsurface ocean.

“For a long time people have thought about the thermal evolution of Pluto and the ability of an ocean to survive to the present day,” said coauthor Francis Nimmo, professor of Earth and planetary sciences at UC Santa Cruz. “Now that we have images of Pluto’s surface from NASA’s New Horizons mission, we can compare what we see with the predictions of different thermal evolution models.”

Because water expands when it freezes and contracts when it melts, the hot-start and cold-start scenarios have different implications for the tectonics and resulting surface features of Pluto, explained first author and UCSC graduate student Carver Bierson.

“If it started cold and the ice melted internally, Pluto would have contracted and we should see compression features on its surface, whereas if it started hot it should have expanded as the ocean froze and we should see extension features on the surface,” Bierson said. “We see lots of evidence of expansion, but we don’t see any evidence of compression, so the observations are more consistent with Pluto starting with a liquid ocean.”

Extensional faults (arrows) on the surface of Pluto indicate expansion of the dwarf planet’s icy crust, attributed to freezing of a subsurface ocean.

Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Alex Parker

The thermal and tectonic evolution of a cold-start Pluto is actually a bit complicated, because after an initial period of gradual melting the subsurface ocean would begin to refreeze. So compression of the surface would occur early on, followed by more recent extension. With a hot start, extension would occur throughout Pluto’s history.

“The oldest surface features on Pluto are harder to figure out, but it looks like there was both ancient and modern extension of the surface,” Nimmo said.

The next question was whether enough energy was available to give Pluto a hot start. The two main energy sources would be heat released by the decay of radioactive elements in the rock and gravitational energy released as new material bombarded the surface of the growing protoplanet.

Bierson’s calculations showed that if all of the gravitational energy was retained as heat, it would inevitably create an initial liquid ocean. In practice, however, much of that energy would radiate away from the surface, especially if the accretion of new material occurred slowly.

“How Pluto was put together in the first place matters a lot for its thermal evolution,” Nimmo said. “If it builds up too slowly, the hot material at the surface radiates energy into space, but if it builds up fast enough the heat gets trapped inside.”

The researchers calculated that if Pluto formed over a period of less that 30,000 years, then it would have started out hot. If, instead, accretion took place over a few million years, a hot start would only be possible if large impactors buried their energy deep beneath the surface.

The new findings imply that other large Kuiper belt objects probably also started out hot and could have had early oceans. These oceans could persist to the present day in the largest objects, such as the dwarf planets Eris and Makemake.

“Even in this cold environment so far from the sun, all these worlds might have formed fast and hot, with liquid oceans,” Bierson said.

In addition to Bierson and Nimmo, the paper was coauthored by Alan Stern at the Southwest Research Institute, the principal investigator of the New Horizons mission.

Contacts and sources:

Tim Stephens

University of California - Santa Cruz

Publication: Evidence for a hot start and early ocean formation on Pluto Carver J. Bierson, Francis Nimmo & S. Alan Stern Nature Geoscience (2020https://www.nature.com/articles/s41561-020-0595-0 http://dx.doi.org/10.1038/s41561-020-0595-0  Source: https://www.ineffableisland.com: 

Read More........→June 23, 2020

Largest Solar System Moon Detailed in Geologic Map

Animation of a rotating globe of Jupiter's moon Ganymede, with a geologic map superimposed over a global color mosaic. The 37-second animation begins as a global color mosaic image of the moon then quickly fades in the geologic map. The views incorporate the best available imagery from NASA's Voyager 1 and 2 spacecraft and NASA's Galileo spacecraft. To present the best information in a single view of Jupiter's moon Ganymede, a global image mosaic was assembled, incorporating the best available imagery from NASA's Voyager 1 and 2 spacecraft and NASA's Galileo spacecraft. This image shows Ganymede centered at 200 west longitude. This mosaic (right) served as the base map for the geologic map of Ganymede (left). Video credit (top): USGS Astrogeology Science Center/Wheaton/ASU/NASA/JPL-Caltech; image credit (bottom): USGS Astrogeology Science Center/Wheaton/NASA/JPL-Caltech Note: For more information, see Largest Solar System Moon Detailed in Geologic Map. Source: Article

Read More........→February 18, 2014

Telescope finds solar system that mirrors ours - and offers hope that life could thrive on its worlds

A solar system arranged just like our own has been discovered a thousand light years from the Earth. The group of planets line up in a way similar to those in our solar systems, with their orbital planes aligned with the equator of their Sun. Dr Roberto Sanchis-Ojeda and colleagues analysed their transits over spots on the Sun-like star Kepler-30 and found they mirrored those round our Sun. In our solar system the Sun’s equator and the planets’ orbital planes are nearly aligned, presumably a consequence of their formation from a single spinning gaseous disk. There are only three planets in the alien solar system, compared to the eight in ours, but it is the first time one with the same alignment as our own has been found. The observation described in Nature sheds light on the conditions that determine the architecture of a planetary system. Many such ‘exoplanets’ do not display this arrangement and isolated ‘hot Jupiters’ - giant planets that orbit too close to their parent stars to harbour life - are often misaligned, some even with opposite orbits. Source: The Coming Crisis

Read More........→July 26, 2012

Solar system mystery 'solved'

Indian  Express,  Agencies : Washington,  Planetary scientists claim  they  may  have  discovered  how
"chondrules", tiny particles found in meteorites, formed at the beginning of the solar system, thus solving the decades-old cosmic conundrum. Chondrules are spherical particles of molten material found in meteorites but their origins have long been a mystery. No longer than about one millimetre in diameter, they melted at temperatures of more than 1,000 degrees Celsius, while the cooler materials surrounding them only experienced temperatures of a few hundred degrees Celsius. Now, an international team, led by Australian National University, has cracked the mystery as to how "chondrules" could have actually formed in extreme heat, especially when the meteorite structure surrounding them remained cold. "Most of the solar system is cold,   experience  such extreme  heat. We  believe  so  it's  been  unclear  for  decades  what caused the chondrules to that chondrules formed in jets of material ejected from flattened discs, called 'protostellar discs', which encircle young stars. "These discs are somewhat like the rings around the planet Saturn. The modern planets are the remnants of material of these discs clumping together. In observations of the formation of new stars, we can see jets of material accelerating out of protostellar discs. "We show that as these jets shoot out of the discs, from about the Earth-Sun distance away, the materials brought with them are heated to the point of melting. The heavier items in them then drop back into the discs, where they cool and re-form," Raquel Salmeron, who led the team, said. The scientists said that their theory challenged old assumptions about the formation of chondrules. "For decades it has been assumed that jets could only form chondrules through the heating of materials in the vicinity of the Sun, followed by their transportation into protostellar discs," Salmeron said in a varsity release. "We believe that our new theory explains how chondrules -- among the earliest materials in the solar system -- reached the temperatures required for melting, even though the early solar nebula was cold. It also explains the fairly uniform size of chondrules and provides a means for them to mix and combine with unheated material," Salmeron added. Image Link Photobucket, Source: Indian Express

Read More........→April 19, 2012

11 new solar systems hosting 26 planets discovered

Agencies : Washington,The Kepler space telescope science team has confirmed the discovery of 11 star systems piled with 26 exoplanets. With this latest revelation, the number of known multi-planetary star systems has just tripled and the list of confirmed planets beyond our solar system has doubled. “Prior to the Kepler mission, we knew of perhaps 500 exoplanets across the whole sky,” Discovery News quoted Doug Hudgins, Kepler program scientist at NASA Headquarters in Washington, D.C as saying. “Now, in just two years staring at a patch of sky not much bigger than your fist, Kepler has discovered more than 60 planets and more than 2,300 planet candidates. This tells us that our galaxy is positively loaded with planets of all sizes and orbits,” Hudgins said. Although these stars may have nearly a number of planets each, but that is where the similarities to our own solar system end. The worlds in each of these star systems have very compact orbits -- the shortest orbital period (or “year”) is six days while the longest is just 143 days. In contrast, the orbital period of Mercury is 115 days. All of these worlds have an orbital distance closer than Venus is to the sun.  The range of the recently discovered systems includes some, which are only 1.5 times the size of Earth, while others that are larger than Jupiter. Fifteen exoplanets are between Earth and Neptune in size, but further observations will be required to establish if any of them have a rocky surface like Earth, or a gaseous consistency like Neptune.Source: Indian Express

Read More........→April 18, 2012

Re-writing the history of solar system?

Indian Express, Agencies : Washington, The early days of our solar system might look quite different than previously thought, claim physicists. In its research, a team at the US Department of Energy's Argonne National Laboratory used more sensitive instruments to find a different half-life for samarium, one of the

Read More........→April 11, 2012