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Cosmos In Brief - Aktualní novinky vesmírného výzkumu v kostce
VIRGO
Máte k tomu co říct? Vložte se do diskuze.
VIRGO --- 19:18:28 24.11.2017
The Tyranny of Extraterrestrial Messaging - Scientific American Blog Network
https://blogs.scientificamerican.com/life-unbounded/the-tyranny-of-extraterrestrial-messaging/

Some of the basic assumptions we make about extraterrestrial communication can be woefully naïve. Consider the situation in its gory detail.
You decide (perhaps as a species, or perhaps as some resource-rich subset) that you want to ping the cosmos to find out if something else is
listening, thinking, and as technological as you are. So you fire up your radio transmitter, or your big laser and start shooting off ‘Hello’
messages.

If our circumstances represent a useful template it means that the earliest possible response might come within about 8 years (Earth years of
course). That's assuming that there is a responder in the nearest exoplanetary system, listening and receiving your first message at the right
time, ready to fire back a response right away, willing to fire back a response, and capable of firing back something recognizable as a response.
So, you start listening carefully 8 years later. But nothing comes in. So, you keep listening, telling yourself that it may take time for anyone
to put a response together. And you keep listening.

Meanwhile, you’ve been busy. In the last 8 years you’ve been pinging the next furthest stellar systems. But for these the roundtrip light travel
times go up to 10 years, 20 years, 40 years. Within the sphere of space for a 40-year messaging roundtrip are roughly 150 stars.
VIRGO --- 18:34:27 24.11.2017
Shards, Axis Ratios and Interstellar Objects
https://www.centauri-dreams.org/?p=38854

With ‘Oumuamua, though, we now have to ask whether the 10 to 1 ratio is actually correct, as Jason Wright noted in a recent post.
The problem here is that, unlike the situation with Boyajian’s Star, we have a small dataset to work with, and according to Wright
(Penn State), researchers are getting different aspect ratios, ranging all the way from the aforementioned 10 to 1 down to
a relatively ordinary 3 to 1.

If the latter is the case, the interstellar object may look something more like Haumea than the Shard. “I’ll need to see a lot more
data and hard, critical analysis of the anomalies in ‘Oumuamua before I get interested in the SETI angle at the level I am for Tabby’s
Star,” adds Wright.
VIRGO --- 18:07:47 24.11.2017
JULIANNE --- 22:27:07 21.11.2017
Jen si tu odložím drobnou pozvánku...
Jak se žije na Marsu – BIO|OKO – nejlepší kino na Praze 7
http://www.biooko.net/cz/film/9346/Jak-se-zije-na-Marsu/
BROUKOID --- 22:09:27 21.11.2017
JAKKILLER: az v periheliu prece :)
VIRGO --- 19:39:04 21.11.2017
https://www.nasa.gov/feature/goddard/2017/nasa-telescope-studies-quirky-comet-45p

When comet 45P zipped past Earth early in 2017, researchers observing from NASA’s Infrared Telescope Facility, or IRTF,
in Hawai’i gave the long-time trekker a thorough astronomical checkup. The results help fill in crucial details about ices
in Jupiter-family comets and reveal that quirky 45P doesn’t quite match any comet studied so far.

Like a doctor recording vital signs, the team measured the levels of nine gases released from the icy nucleus into the comet’s
thin atmosphere, or coma. Several of these gases supply building blocks for amino acids, sugars and other biologically relevant
molecules. Of particular interest were carbon monoxide and methane, which are so hard to detect in Jupiter-family comets that
they’ve only been studied a few times before.

[https://www.nasa.gov/sites/default/files/styles/full_width/public/thumbnails/image/comet45p_geraldrhemann_361_45p_22_12c_0.jpg?itok=g6AYePzU]
VIRGO --- 19:38:29 21.11.2017
Astronomers Reveal Nearby Stars That Are Among The Oldest In Our Galaxy - News Hub -
http://news.gsu.edu/2017/11/19/astronomers-reveal-nearby-stars-among-oldest-galaxy/

Astronomers have discovered some of the oldest stars in our Milky Way galaxy by determining their locations and velocities, according to a study led by scientists at
Georgia State University. This study focused on old or “senior citizen” stars, also known as cool subdwarfs, that are much older and cooler in temperature than the sun.

In this study, published in the November 2017 edition of The Astronomical Journal, astronomers conducted a census of our solar neighborhood to identify how many young,
adult and old stars are present. They targeted stars out to a distance of 200 light years, which is relatively nearby considering the galaxy is more than 100,000 light
years across. A light year is how far light can travel in one year. This is farther than the traditional horizon for the region of space that is referred to as “the
solar neighborhood,” which is about 80 light years in radius.
VIRGO --- 19:28:17 21.11.2017
Press Release - Uncovering the Origins of Galaxies' Halos
https://www.naoj.org/Pressrelease/2017/08/02/index.html

Using the Subaru Telescope atop Maunakea, researchers have identified 11 dwarf galaxies and two star-containing halos
in the outer region of a large spiral galaxy 25 million light-years away from Earth. The findings, published in The
Astrophysical Journal, provide new insight into how these 'tidal stellar streams' form around galaxies.

Researchers from Tohoku University and colleagues used an ultra-wide field of view camera on the Subaru Telescope to
develop a better understanding of stellar halos. These ring-shaped collections of stars orbit large galaxies and can
often originate from smaller dwarf galaxies nearby.

The team focused their attention on Galaxy NGC 4631, otherwise known as the Whale Galaxy because of its shape. They
identified 11 dwarf galaxies in its outer region, some of which were already known. Dwarf galaxies are not easily
detected because of their small sizes, masses and low brightness. The team also found two tidal stellar streams orbiting
the galaxy: one, called Stream SE, is located in front of it and the other, called Stream NW, is nestled behind it.

[https://www.naoj.org/Pressrelease/2017/08/02/fig2e.jpg]
VIRGO --- 15:31:43 21.11.2017
Kepler Planets Tend to Have Siblings of the Same Size
http://aasnova.org/2017/11/20/kepler-planets-tend-to-have-siblings-of-the-same-size/

After 8.5 years of observations with the Kepler space observatory, we’ve discovered a large number of close-in, tightly-spaced, multiple-
planet systems orbiting distant stars. In the process, we’ve learned a lot about the properties about these systems — and discovered some
unexpected behavior. A new study explores one of the properties that has surprised us: planets of the same size tend to live together.

[http://aasnova.org/wp-content/uploads/2017/11/fig2-6.jpg]