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Also impoertant:
X-rays may sterilize otherwise habitable exoplanets
"Red dwarfs are far and away the most common type of star. These slow and steady burners are thought to account for roughly 75 percent of the stars in the Milky Way, and for the most part, astronomers agree that red dwarfs are prevalent throughout the entire universe. Furthermore, many exoplanets — including the seven Earth-size planets found in the TRAPPIST-1 system — have been detected around red dwarfs.
Because these stable stars are relatively cool (around 7,000 degree Fahrenheit) and live exceptionally long (trillions of years), it may seem like they would be the perfect places to hunt for habitable exoplanets. However, according to new research presented on April 3 at the European Week of Astronomy and Space Science in Liverpool, red dwarfs may be much more inhospitable to life than we previously thought.
The problem lies in the fact that red dwarfs are so darn cool. For any exoplanet to get enough heat to be in a red dwarf’s habitable zone — the region around a star where liquid water can exists — the planet must sit extremely close to the star itself. And since red dwarfs often emit large radiation flares, spew out charged particles, and undergo coronal mass ejections (CMEs; think plasma torpedoes), being near one is a risky proposition.
[...]the X-ray radiation associated with the flare-up would have cut through an Earth-sized planet’s atmosphere like a hot knife through butter. This means that copious amounts of harmful X-rays would penetrate straight down to the surface of any potential exoplanet in the habitable zone around AD Leo, effectively sterilizing the entire planet."
http://www.astronomy.com/news/2018/0...ble-exoplanets
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This was interesting. Thanks, Danik!
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Interesting images:
Fascinating zoo of discs discovered around young stars
Date:
April 11, 2018
Source:
ESO
Summary:
New images from the SPHERE instrument on ESO's Very Large Telescope are revealing the dusty discs surrounding nearby young stars in greater detail than previously achieved. They show a bizarre variety of shapes, sizes and structures, including the likely effects of planets still in the process of forming.
https://www.sciencedaily.com/release...0411111106.htm
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The impressive fact is that we get to know about these storms.
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Yes, Saturn is quite far away from us.
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Good news for amateur astronomers
THE NEWSPACE REVOLUTION IS ABOUT TO BRING US TINY SPACE TELESCOPES WE CAN ALL CONTROL
"One of the defining characteristics of the modern era of space exploration is the way the public and private aerospace companies (colloquially referred to as the NewSpace industry) and are taking part like never before. Thanks to cheaper launch services and the development of small satellites that can be built using off-the-shelf electronics (aka. CubeSats and microsats), universities and research institutions are also able to conduct research in space.
Looking to the future, there are those who want to take public involvement in space exploration to a whole new level. This includes the California-based aerospace company Space Fab that wants to make space accessible to everyone through the development the Waypoint Space Telescope – the first space telescope that people will be able to access through their smartphones to take pictures of Earth and space."
https://www.universetoday.com/138942...n-all-control/
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Yes I saw this in Universe today. Also luxury hotels in space.
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Lol! That will take a very long time, I think!
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Two facts stand out regarding the Piri Reis Map of the Americas.
One is the island of Cuba in the far north: https://en.wikipedia.org/wiki/Piri_Reis_map. It looks like it is drawn on an equidistant projection based on Cairo, Egypt. Such a map would have Cuba running north-south , instead of east-west just as on the Piri Reis map (see figures 25 to 27, pages 52 to 53).
The other is the map of Antarctica, its coasts shown free of ice, and possibly directly connected to the tip of South America (see the Piri Reis map above).
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Sure. But in this comparison with a later image you can see what I mean. The Brazilian coast is very accurately drawn.
http://silentcircle.co.uk/the-myster...-civilization/
Thanks for introducing me to Piri Reis Maps.
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Charles H. Hapgood's book is called Maps of the Ancient Sea KingsThe subtitle for this book is "Evidence for Advanced Civilisations in the Ice Age". This is not discussed in the book I bought, not at all. But it seems to be a conclusion Hapgood comes to anyway.
What has to do with space, or with astronomy?
See this article in Universe Today: https://www.universetoday.com/139034...ogical-record/
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It all started with the Piri Maps. So I think we remained in the realm of space, but digressed from astronomy
So, back to astronomy:
"COULD WE DETECT AN ANCIENT INDUSTRIAL CIVILIZATION IN THE GEOLOGICAL RECORD?
As a species, we humans tend to take it for granted that we are the only ones that live in sedentary communities, use tools, and alter our landscape to meet our needs. It is also a foregone conclusion that in the history of planet Earth, humans are the only species to develop machinery, automation, electricity, and mass communications – the hallmarks of industrial civilization.
But what if another industrial civilization existed on Earth millions of years ago? Would we be able to find evidence of it within the geological record today? By examining the impact human industrial civilization has had on Earth, a pair of researchers conducted a study that considers how such a civilization could be found and how this could have implications in the search for extra-terrestrial life."
I think a similar civilization to ours in the regions astronomers have access to by now, would have been detected already. But who warants, there aren´t more sophisticated civilizations around, that are able to hide from our scrutinies and that aren´t interested in humans?
