Astronomy: space conquest and the latest news from the stars

[moinsdewatt]

Yesterday evening pretty conjunction of the moon with Venus. In addition there is still Mars clearly visible, and also Jupiter.

I spent an hour looking at the sky, and I finally managed to identify the Dragon.

[Christophe]

https://www.levif.be/actualite/sciences ... 53641.html

A UFO over Ireland?
14 / 11 / 18 to 10: 59 - Updated to 10: 59

Three pilots reported seeing, at the same time, strange beams of bright lights running at great speed near their planes. The incident occurred on Friday November 9 over the Irish coast, says the BBC.

The Irish Aviation Authority (IAA) has launched an investigation following complaints from several pilots who allegedly saw unidentified objects over Ireland. The first incident happened last Friday, during a British Airways flight from Montreal to London. The pilot asked the control tower at Shannon Airport if there was a drill, but it was not. The pilot specifies in her report that she had seen a "very bright light" and an object which flew on the left side of the plane before quickly disappearing towards the north.

Several cases

Other pilots also reported flying objects moving at high speed. One of these pilots said that there were several flying objects on the same path and that they were very bright. Another pilot speaks of "two bright lights" flying at high speed, an "astronomical speed, maybe twice the speed of sound".

An ongoing investigation

Irish aviation authorities take complaints seriously. The IAA admitted that reports of "unusual activity" had been made and that, according to procedure, an investigation would take place.

There were precedents in California, but these were military exercises. A track denied in this case. Leaving the way open to many interpretations.

Shooting stars?

According to Apostolos Christou, an astronomer with the Armagh Observatory and Planetarium, the pilots likely saw a piece of dust entering Earth's atmosphere at very high speed. "They were probably what are commonly called shooting stars," he told the BBC. “It looked like the material was extremely shiny so it must have been a big chunk. I can't tell from the pilots' description, but it could have been the size of a walnut or an apple. It also appears that there were pieces breaking away from the object and going past the plane.This is also what one would expect if large pieces of rock hit the atmosphere, as they tend to fragment. "

[izentrop]

They are disturbed by the brexit ... the hallucinations of the first missiles of discord.

[Christophe]

Ahahah, yet the IRA was dissolved a few years ago ...

[izentrop]

A giant impact crater discovered in Greenland

About ten years ago, geoscience researchers proposed a fascinating hypothesis, however quickly controversial. It still is, so it is not considered by the scientific community and even less accepted. This hypothesis was intended to be, in particular, a plausible response to the appearance of a sudden enigmatic and recent cold wave on Earth during a period known as the recent Dryas, about 12.900 years ago. A cold wave that also accompanied a series of notable extinction in North America, especially that of mammoths ...

An astrobleme in Greenland younger than the Meteor Crater?
However, the question is whether this scenario, albeit in a slightly modified form, will not come to life again after the resounding publication of an article in the journal Science Advances. An international team of researchers led by members of the Natural History Museum of Denmark, located in Copenhagen, announce that they have discovered what appears to be an impact crater of 31 kilometers in diameter under the Greenland Ice Sheet, more exactly to the northwest, bordering the Hiawatha Glacier.

The article does not look at the hypothesis mentioned above, but it nevertheless goes on to say that the formation of the astrobleme is necessarily recent at the geological scale, there are less than 3 million years. It could even date from only 12.000 years ago ... https://www.futura-sciences.com/planete ... land-39734

See as well https://www.nasa.gov/press-release/inte ... enland-ice
And the recent discovery. http://advances.sciencemag.org/content/4/11/eaar8173

[moinsdewatt]

Fascinating!
Thanks for the video.

[izentrop]

A folder of 2 pages on https://trustmyscience.com/decouverte-g ... -groenland

An impact with destructive consequences
The impact would have been a show for anyone within 500 kilometers. A white fireball four times bigger and three times brighter than the Sun would have fallen from the sky. If the object hit a layer of ice, it would have penetrated the bedrock, vaporizing the water and the stone in a flash. The resulting explosion summoned the energy of 700 nuclear bombs from 1 megaton.

Even an observer hundreds of miles away would have been hit by a shock wave, a monstrous thunderclap and hurricane force winds. Later, rock debris could have rained down on North America and Europe, and the released steam, a greenhouse gas, could have warmed Greenland locally, melting more ice.

The news of the discovery of an impact has awakened an old debate among scientists studying the paleoclimate. A massive impact on the pack ice would have caused a flow of water into the Atlantic Ocean, potentially disrupting the convective belt of ocean currents and causing a drop in temperatures, particularly in the northern hemisphere. "What would that mean for the species or for life at the time? That's a big question, "says Jennifer Marlon, paleoclimatologist at Yale University.

An assumption severely criticized by the scientific community
The team was immediately criticized. The decline of mammoths, giant sloths and other species had begun well before the Younger Dryas. In addition, there has been no sign of human mortality in North America, archaeologists said. The nomads of the Clovis people would not have stayed long in any site. In other words, the impact hypothesis was trying to solve problems that did not need to be solved.
Geochemical evidence has also begun to erode. Other investigations could not detect the iridium peak in the samples of the group. The pearls were real, but they were abundant throughout many geological periods, and soot and charcoal did not seem to show a clear increase in the recent Dryas ...

In 2013, Jacobsen examined an ice core from central Greenland, at 1000 kilometers away. He expected to end the Younger Dryas impact theory by showing that there are 12'800 years, metal levels that asteroid impacts tend to increase, have not revealed peaks. Instead, he discovered a platinum peak, similar to that measured in samples taken from the crater site.

Richard Alley, a glaciologist at Pennsylvania State University estimates meanwhile, that the impact is much older than 100'000 years and that a subglacial lake can explain the strange textures near the base of the ice ... .

As long as scientists can not date this impact crater accurately, the hypothesis of an asteroid at the origin of the Younger Dryas event will remain unresolved. To do this, researchers plan to drill deeper into the ice to directly access internal rocks and use radioactivity as a method of dating.

[moinsdewatt]

NASA has chosen the landing site for its next Martian vehicle

November 19 2018

The next NASA rover on Mars, christened Mars 2020, will land in a former dry delta called Jezero, the US space agency announced Monday, looking for traces of an old microbial life on the red planet.

The site chosen, after years of debates and scientific deliberations, is the crater of Jezero, which was a lake of 500 meters deep opening on a network of rivers 3,5 3,9 billion years ago.


.......
Mars 2020 is expected to cost 2,5 billion dollars to NASA. It will be launched in July 2020, for a landing in February 2021.
........

https://actu.orange.fr/societe/high-tec ... 19eCoc.amp

[Christophe]

Landing on Mars Live (well direct + 20 minutes approximately) ... but shouldn't we say "Amarssisage"?

[Christophe]

Postponed for 20: 00!

The official stream: https://mars.nasa.gov/insight/timeline/ ... ch-online/