Close encounters of the stellar kind / Gaia / Space Science / Our Activities / ESA
http://www.esa.int/Our_Activities/Space_Science/Gaia/Close_encounters_of_the_stellar_kind

The movements of more than 300 000 stars surveyed by ESA’s Gaia satellite reveal that rare close encounters with our Sun
might disturb the cloud of comets at the far reaches of our Solar System, sending some towards Earth in the distant future.

As the Solar System moves through the Galaxy, and as other stars move on their own paths, close encounters are inevitable –
though ‘close’ still means many trillions of kilometres.

A star, depending on its mass and speed, would need to get within about 60 trillion kilometres before it starts to have an
effect on the Solar System’s distant reservoir of comets, the Oort Cloud, which is thought to extend out to 15 trillion
kilometres from the Sun, 100 000 times the Sun–Earth distance.

For comparison, the outermost planet Neptune orbits at an average distance of about 4.5 billion kilometres, or 30 Sun–Earth
distances. The gravitational influence of stars that pass near the Oort Cloud could perturb the paths of comets residing there,
jolting them onto orbits that bring them in to the inner Solar System.

While this is thought to be responsible for some of the comets that appear in our skies every hundred to thousand years,
it also has the potential to put comets on a collision course with Earth or other planets.

Tracking stellar motions
https://www.youtube.com/watch?v=KCEr8PqeLWI

Hubble delivers first hints of possible water content of TRAPPIST-1 planets | ESA/Hubble
http://www.spacetelescope.org/news/heic1713/

An international team of astronomers used the NASA/ESA Hubble Space Telescope to estimate whether there might be water
on the seven earth-sized planets orbiting the nearby dwarf star TRAPPIST-1. The results suggest that the outer planets
of the system might still harbour substantial amounts of water. This includes the three planets within the habitable
zone of the star, lending further weight to the possibility that they may indeed be habitable.

Animation of the planets orbiting TRAPPIST-1
https://www.youtube.com/watch?v=KPWnBhjXSd0

Discovery of a Metal-Poor Little Cub
http://aasnova.org/2017/08/30/discovery-of-a-metal-poor-little-cub/

The discovery of an extremely metal-poor star-forming galaxy in our local universe, dubbed Little Cub,
is providing astronomers with front-row seats to the quenching of a near-pristine galaxy.

Ultraviolet light may be ultra important in search for life
https://phys.org/news/2017-08-ultraviolet-ultra-important-life.html

A new study by Sukrit Ranjan of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., and colleagues suggests
that red dwarf stars might not emit enough UV light to kick-start the biological processes most familiar to our planet. For example,
certain levels of UV might be necessary for the formation of ribonucleic acid, a molecule necessary for all forms of known life.

NASA's Juno spacecraft will make its seventh science flyby over Jupiter's mysterious cloud tops on Friday, Sept. 1,
at 2:49 p.m. PDT (5:49 p.m. EDT and 21:49 UTC). At the time of perijove (defined as the point in Juno's orbit when it is
closest to the planet's center), the spacecraft will be about 2,200 miles (3,500 kilometers) above the planet's cloud tops.

Juno Scientists Prepare for Seventh Science Pass of Jupiter | Mission Juno
https://www.missionjuno.swri.edu/news/scientists-prepare-for-seventh-jupiter-pass

V pátek!
Asteroid Florence Pays Earth a Visit - Sky & Telescope
http://www.skyandtelescope.com/observing/see-asteroid-florence-fly-by-earth-this-week/



http://www.news.com.au/...steroid-florence-to-skim-earth/news-story/153579213b52c7698b089d630cb761c1

Repríza JPL telkonu "Grande Finale"
NASA Live: JPL - Previewing Cassini's Grand Finale
https://www.youtube.com/watch?v=Y5MqidJ_HfA

Researchers hypothesize how the universe became filled with light | Iowa Now
https://now.uiowa.edu/2017/08/researchers-hypothesize-how-universe-became-filled-light

Black holes may have punctured darkened galaxies, allowed light to escape

Soon after the Big Bang, the universe went completely dark.

The intense, seminal event that created the cosmos churned up so much hot, thick gas that light was completely trapped.
Much later—perhaps as many as one billion years after the Big Bang—the universe expanded; became more transparent;
and eventually filled up with galaxies, planets, stars, and other objects that give off visible light. That’s the universe
we know today.

How it emerged from the cosmic dark ages to a clearer, light-filled state remains a mystery.

In a new study, researchers at the University of Iowa offer a theory of how that happened. They think black holes that dwell
in the center of galaxies fling out matter so violently that the ejected material pierces its cloudy surroundings, allowing light
to escape. The researchers arrived at their theory after observing a nearby galaxy from which ultraviolet light is escaping.

ALMA nalezla mohutné skryté zásoby plynu ve vzdálené galaxii | ESO Česko
http://www.eso.org/public/czechrepublic/news/eso1727/?lang

První pozorování molekul CH+ ve vzdálené galaxii s aktivní hvězdotvorbou poskytují nový pohled na historii vzniku hvězd ve vesmíru

Zooming in on the Cosmic Eyelash
https://www.youtube.com/watch?v=4KytNHz30AY


Astronomové využili radioteleskop ALMA k pozorování turbulentních rezervoárů chladného plynu obklopujících vzdálené galaxie, ve kterých probíhá
prudký vývoj nových hvězd. Díky tomu, že se vědcům poprvé v historii podařilo v těchto galaxiích detekovat molekulu CH+, otevírá tento výzkum
zcela nové okno umožňující zkoumat kritické fáze vývoje hvězd ve vesmíru. Přítomnost těchto molekul přináší nový pohled na způsob, jakým galaxie
dosáhnou prodloužení období bouřlivé hvězdotvorby. Výsledky byly publikovány v prestižním vědeckém časopise Nature.

TOXYGEN: Včerejší 10h srážení iontů olova na LHC (detektor ALICE provádí srážky
většinou poslední týden v měsíci), a úhrnná vzdálenost, kterou částice urazily.

VIRGO: co to je?

Zajímavý vývoj kardinální otázky...
Cassini hints at young age for Saturn's rings - BBC News
http://www.bbc.com/news/science-environment-41091333

The spectacular rings of Saturn may be relatively young, perhaps just 100 million years or so old.
This is the early interpretation of data gathered by the Cassini spacecraft on its final orbits of the giant world.
If confirmed, it means we are looking at Saturn at a very special time in the age of the Solar System.
Cassini is scheduled to make only two more close-in passes before driving itself to destruction in Saturn's atmosphere on 15 September.

The end-Cretaceous mass extinction was rather unpleasant | Ars Technica
https://arstechnica.com/science/2017/08/the-end-cretaceous-mass-extinction-was-rather-unpleasant/

Climate simulation shows how long soot blotted out the Sun.

There are a few hellish episodes in Earth’s unfathomably long history that make even Hollywood’s most bombastic disaster movie
look like a sunny picnic. The end-Cretaceous extinction is the most well-known, since it wiped out the dinosaurs (minus the birds,
of course) and opened the door for the mammalian revolution—which most human beings regard as generally a good thing.

Though the story is probably familiar, there are still significant questions about exactly what happened during that cataclysm.
Many species were seemingly in trouble before that colossal meteoroid crashed into the coastal Yucatan, perhaps partly because of
a long-lived series of massive volcanic eruptions in what is now India. This has led some to question whether the impact was as
deadly as it's made out to be. But we've also filled in some details of just how the meteoroid impact would mess up the Earth,
and these include mind-blowing tsunamis, rampant wildfires, and see-sawing climate effects. So how lethal was the impact?

Kepler Stares at Neptune
https://www.youtube.com/watch?v=jUvcaYFEWac