New Horizons - misja podstawowa

[kanarkusmaximus]

Jutro zakończy się transmisja kompletu danych z przelotu przez układ Plutona.

Trwało to jednak dłużej niż się spodziewano...

[Orionid]

Po przebyciu ponad 5 miliardów kilometrów (5 godzin 8 minut świetlnych), ostatnie zdjęcie układu Pluton-Charon wykonane za pomocą kamery Ralph/LEISA dotarło do centrum kontroli misji w Johns Hopkins Applied Physics Laboratory (APL) w Laurel w stanie Maryland o godzinie 5.48 25 października br. Zdjęcie odebrane zostało za pomocą stacji DSN (Deep Space Network) w Canberra w Australii. Były to ostatnie dane z ponad 50 gigabajtów danych przesyłanych na Ziemię w ciągu ostatnich 15 miesięcy.

Źródło http://www.pulskosmosu.pl/2016/10/28/new-horizons-zakonczyla-przesylanie-danych-z-przelotu-w-poblizu-plutona/
http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20161027

[Orionid]

Pod Sputnik Planitia, wg danych z NH znajduje się ocean lodowy.

Beneath Pluto's "heart" lies a cold, slushy ocean of water ice, according to data from NASA's New Horizons mission. In a paper published today in the journal Nature, the New Horizons team, including researchers from MIT, reports that the dwarf planet's most prominent surface feature—a heart-shaped region named Tombaugh Regio—may harbor a bulging, viscous, liquid ocean just below its surface.

The existence of a subsurface ocean may solve a longstanding puzzle: For decades, astronomers have observed that Tombaugh Regio, which is Pluto's brightest region, aligns almost exactly opposite from the dwarf planet's moon, Charon, in a locked orientation that has lacked a convincing explanation.

A thick, heavy ocean, the new data suggest, may have served as a "gravitational anomaly," or weight, which would factor heavily in Pluto and Charon's gravitational tug-of-war. Over millions of years, the planet would have spun around, aligning its subsurface ocean and the heart-shaped region above it, almost exactly opposite along the line connecting Pluto and Charon.

http://phys.org/news/2016-11-horizons-mission-water-ice-ocean-lies.html
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature20148.html

[Orionid]

Pojawiła się hipoteza o możliwym istnieniu prymitywnego życia w oceanie pod powierzchnią Sputnik Planitia.

But the ocean uplift won't last if warm water ice at the base of the covering ice shell can flow and adjust in the manner of glaciers on Earth. Add enough ammonia to the water, and it can chill to incredibly cold temperatures (down to minus 145 Fahrenheit) and still be liquid, even if quite viscous, like chilled pancake syrup. At these temperatures, water ice is rigid, and the uplifted surface ocean becomes permanent.

"All of these ideas about an ocean inside Pluto are credible, but they are inferences, not direct detections," McKinnon said, sounding the call. "If we want to confirm that such an ocean exists, we will need gravity measurements or subsurface radar sounding, all of which could be accomplished by a future orbiter mission to Pluto. It's up to the next generation to pick up where New Horizons left off!"

http://phys.org/news/2016-12-life-pluto-ocean.html

[ekoplaneta]

A jakie dowody na istnienie tego życia? 

[Orionid]

Na dowody życia lub jego braku potrzebna jest misja in situ.
Na razie nie można tego wykluczyć, zważając tylko na ramowe warunki sprzyjające egzystencji prymitywnych mikroorganizmów. Glob odległy, a na w miarę bliskim Marsie dopiero może ExoMars 2020 coś pewniejszego ustali.

[Orionid]

Nowe badania zdają się wskazywać, że Sputnik Planitia powstał w początkowym okresie ewolucji Plutona i nie w konsekwencji impaktu.

"The main difference between my model and others is that I suggest that the ice cap formed early, when Pluto was still spinning quickly, and that the basin formed later and not from an impact," said Hamilton, who is lead author of the paper. "The ice cap provides a slight asymmetry that either locks toward or away from Charon when Pluto's spin slows to match the orbital motion of the moon."

Using a model he developed, Hamilton found that the initial location of Sputnik Planitia could be explained by Pluto's unusual climate and its spin axis, which is tilted by 120 degrees. For comparison, Earth's tilt is 23.5 degrees. Modeling the dwarf planet's temperatures showed that when averaged over Pluto's 248-year orbit, the 30 degrees north and south latitudes emerged as the coldest places on the dwarf planet, far colder than either pole. Ice would have naturally formed around these latitudes, including at the center of Sputnik Planitia, which is located at 25 degrees north latitude.

http://phys.org/news/2016-11-perspective-pluto-icy-heart.html#nRlv

[ekoplaneta]

Na dowody życia lub jego braku potrzebna jest misja in situ.
Na razie nie można tego wykluczyć, zważając tylko na ramowe warunki sprzyjające egzystencji prymitywnych mikroorganizmów. Glob odległy, a na w miarę bliskim Marsie dopiero może ExoMars 2020 coś pewniejszego ustali.

Ja miałem na myśli życie w oceanie Plutona. Jak na razie mamy tylko przemyślenia dotyczące życia w podlodowych oceanach Europy, Enceladusa, Tytana czy Plutona. Domniemujemy, że jak są tam niezbędne pierwiastki oraz energia (pochodzenia pływowego) to jest duża szansa że życie mogło się tam pojawić. Cząstki krzemionki wykryte przez Cassini w gejzerach Enceladusa sugerują, ze są tam kominy hydrotermalne, które na Ziemi były najprawdopodobniej miejscem powstania życia.
Jak na razie najsilniejsze przesłanki są dla Marsa. Ocean niegdyś tam istniał, Spirit odkrył ślady hydrotermalnych źródeł. Oba łaziki Spirit i Curiosity wykryły struktury przypominające te, które powstają przy udziale działalności ziemskich mikrobów.

[kanarkusmaximus]

Pojawił się śliczny rysunek pokazujący co może się dziać wewnątrz naszego ulubionego obszaru na Plutonie.

[Orionid]

Podsumowanie wyników naukowych  NH w 2016

“Sputnik Planum is one of the most amazing geological discoveries in 50-plus years of planetary exploration, and the finding by McKinnon and others on our science team that this vast area is created by current day ice convection is among the most spectacular of the New Horizons mission,” said Alan Stern. (...)

“Pluto’s small satellites probably all formed out of the cloud of debris created by the impact of a small planet onto a young Pluto,” said New Horizons Project Scientist Hal Weaver.  “So we would expect them all to be made of similar material.  The strong signature of water-ice absorption on the surfaces of [Charon, Nix, and Hydra] adds weight to this scenario.”

However, the striking difference between water ice spectral readings of Nix and Hydra raises new questions, specifically why Nix and Hydra apparently have different ice textures on their surfaces and why Hydra’s surface reflectivity at visible wavelengths is higher than Nix’s even though Nix’s surface appears to be icier.

https://www.nasaspaceflight.com/2016/12/yir-iv-new-horizons-pluto-big-surprises/

[Orionid]

W pracy “Charon Tectonics”  sugeruje się  , że  Charon oprócz przeszłej aktywności tektonicznej posiadał podpowierzchniowy ocean, który obecnie jest w postaci zamrożonej.

(...) The evidence is presented in a new paper in Icarus titled “Charon Tectonics,” and suggests that Charon was not only tectonically active in the past, but also possessed a subsurface ocean which is now frozen. The new paper is a summary of observations from New Horizons’ Long-Range Reconnaissance Imager (LORRI, Cheng et al., 2008) and the Multi-spectral Visible Imaging Camera (MVIC) on the Ralph instrument (Reuter et al., 2008). The conclusion in brief is that Charon has undergone “global extension” which produced the tectonic features seen by New Horizons and provides evidence for the subsurface ocean. Basically, expanding ice in the slowly freezing ocean would cause the surface to stretch and fracture. From the paper:

“The global characteristics of Charon’s tectonics are striking: (1) extension dominates over the entirety of Charon’s northern terrain up to and including the scarps that border Vulcan Planum, whose resurfaced units bury the flanks of the rifts; (2) there is no evidence for compressional faulting or strike-slip faulting; (3) the extension is inferred to be relatively ancient (up to ∼4 Ga), based on the superposition of many craters and Vulcan Planum units, which are themselves relatively heavily cratered; and (4) the roughly polygonal extension across the northern terrain does not indicate a preferred direction of extensional stress, whereas the roughly east-west alignment of the major chasmata implies major north-south extension across the entire structural belt represented by the chasmata. (...)

http://www.americaspace.com/?p=97434

[Orionid]

4-JAN-2017
York U research identifies icy ridges on Pluto
YORK UNIVERSITY

TORONTO, January 4, 2017 - Using a model similar to what meteorologists use to forecast weather on Earth and a computer simulation of the physics of evaporating ices, a new study published in the journal, Nature by York University's Professor John Moores, Department of Earth and Space Science and Engineering at York's Lassonde School of Engineering, has found evidence that snow and ice features previously only seen on Earth, have been spotted on Pluto.

"Penitentes" which are formed by erosion, are bowl-shaped depressions with spires around the edge, and are several metres high.

The groundbreaking research, done in collaboration with researchers at NASA and Johns Hopkins University, indicates that these icy features may exist on other planets where environmental conditions are similar.

"The identification of the ridges of Tartarus Dorsa as Penitentes suggests that the presence of an atmosphere is necessary for the formation of penitentes, which would explain why they have not previously been seen on other airless icy satellites or dwarf planets," says Moores. "But exotic differences in the environment give rise to features with very different scales. This test of our terrestrial models for penitentes suggests that we may find these features elsewhere in the solar system, and in other solar systems, where the conditions are right."

Moores, along with his York postgraduate fellow, Dr. Christina Smith, Dr. Anthony Toigo, at the Applied Physics Laboratory, Johns Hopkins University and NASA Research Astrophysicist, Dr. Scott D. Guzewich, at the Goddard Space Flight Center in Maryland, USA compared their model to ridges on Pluto imaged by the New Horizons spacecraft in 2015. Pluto's ridges are much larger - 500 metres tall and separated by three to five kilometres - as compared to their meter-sized earthly counterparts.

"This gargantuan size is predicted by the same theory that explains the formation of these features on Earth," says Moores. "In fact, we were able to match the size and separation, the direction of the ridges, as well as their age: three pieces of evidence that support our identification of these ridges as penitentes."

Moores says though Pluto's environment is very different from the Earth - it is much colder, the air much thinner, the sun much dimmer and the snow and ice on the surface are made from methane and nitrogen instead of water - the same laws of nature apply. Both NASA and Johns Hopkins University were instrumental in the collaboration that led to this new finding. Both provided background information on Pluto's atmosphere using a model similar to what meteorologists use to forecast weather on Earth. This was one of the key ingredients in Moores' own models of the penitentes, without which this discovery would not have been made.

https://www.eurekalert.org/pub_releases/2017-01/yu-yur010417.php
artykuł naukowy
http://www.forum.kosmonauta.net/index.php?topic=194.msg101068#msg101068

[Orionid]

Średnica Charona to ponad połowa średnicy Plutona, a odległość między tymi dwoma ciałami to niecałe 20 000 kilometrów. To tak jakby dokoła Ziemi krążył Mars w odległości trzy razy mniejszej od aktualnej odległości Księżyca od Ziemi.

Nowe wyniki badań prowadzonych przez naukowców z Georgia Institute of Technology dostarczają nowych informacji o tym związku i o jego wpływie na bezustanne zdzieranie atmosfery Plutona przez wiatr słoneczny. Gdy Charon znajduje się dokładnie pomiędzy Słońcem a Plutonem znacząco spowalnia tempo utraty atmosfery.

Źródło: http://www.pulskosmosu.pl/2017/01/10/charon-spowalnia-tempo-utraty-atmosfery-na-plutonie/


John Hale is the Georgia Tech student who co-led the study with Paty. He says the Pluto system is a window into our origins because Pluto hasn’t been subjected to the same extreme temperatures as objects in closer orbits to the sun.

“As a result, Pluto still has more of its volatile elements, which have long since been blown off the inner planets by solar wind,” Hale said. “Even at its great distance from the sun, Pluto is slowly losing its atmosphere. Knowing the rate at which Pluto’s atmosphere is being lost can tell us how much atmosphere it had to begin with, and therefore what it looked like originally. From there, we can get an idea of what the solar system was made of during its formation.”

https://www.cos.gatech.edu/hg/item/585677

[Spearhead]

Widoczki z Plutona muszą być niesamowite 

[KP]

Widoczki z Plutona muszą być niesamowite 

Czyli z Plutona widać tak jakby my na Ziemi widzielibyśmy 3x większy księżyc, dobrze myślę?