Showing posts with label Comets. Show all posts
Showing posts with label Comets. Show all posts

Thursday, June 15, 2017

WOW Signal: Was It Aliens Or Just a Comet?

WOW Signal: Was It Aliens Or Just a Comet?

     There’s no such thing as a “close call” in SETI – either the radio telescope has picked up an alien signal, or it hasn’t. “Close” doesn’t exist in this one-bit experiment, any more than it does in pregnancy.
By Seth Shostak
www.seti.org
6-13-17

[...]

... At close to midnight on August 15, 1977, the massive radio telescope of the Ohio State University, known to its friends as the Big Ear, recorded a signal so impressive to the astronomer examining the instrument’s logs, he wrote “Wow!” on the computer printout.

It had all the characteristics one would anticipate from a signal produced by a deep space transmitter. This agreement with hopeful expectation, coupled with the undoubted appeal of the signal’s beguiling moniker, led to many efforts to find the WOW signal a second time. These attempts were made on such radio telescopes as the Very Large Array in New Mexico and, of course, the Big Ear itself. However, the result was always the same: radio silence.

[...]

But a paper published more than a year ago by Antonio Paris and Evan Davies makes a different claim: a natural solution to the puzzle of the WOW signal. It wasn’t earthly interference, problems with the equipment, or even ET; it was natural radio emission from hydrogen gas streaming off a nearby comet. ...

The comet hypothesis, in my opinion, doesn’t work....

Wednesday, June 14, 2017

Alien Argument for 'WOW' Signal Continues ...

Alien Argument for 'WOW' Signal Continues ...

     An astronomer thinks he's pinpointed the source of a mysterious radio signal from space: a passing comet that nobody knew about. But his colleagues said they're still skeptical of the explanation, noting that comets don't emit radio waves in the right way.
By Jesse Emspak
Space.com
6-13-17

[...]

Yet several astronomers, including Ehman, think Paris is wrong about the comet....

"We should have seen the source come through twice in about 3 minutes: one response lasting 72 seconds and a second response for 72 seconds following within about a minute and a half," Ehman told Live Science. "We didn't see the second one."

The only way that can happen, he said, is if the signal was cut off abruptly. A comet wouldn't produce that kind of signal, because the gases that surround them cover large, diffuse areas. Nor would the comet have escaped from the radio telescope's field of view that fast.

Sunday, April 10, 2016

Basic Ingredient of Life Can Form In Comets, Say Researchers

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Basic Ingredient of Life Can Form In Comets, Say Researchers

     An experiment mimicking our early solar system reveals that the sugar ribose, the 'R' in 'RNA,' can arise in the icy grains of comets.

The origin of life on Earth has been a matter of intense debate throughout human history. Even today, scientists don’t know whether the molecular building blocks of life were created on Earth or whether they were brought here by comets and meteorites. This is obviously hugely important – if they were delivered to Earth then it seems plausible that they may have been transported to other planets, too. [...]

By Christian Schroeder
University of Stirling
4-8-16


Saturday, February 22, 2014

The Real Threats From Asteroids Impacting Earth | VIDEO


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The Real Threats From Asteroids Impacting Earth

Accidents and Asteroids

By European Space Agency, ESA
YouTube
2-21-14

     How real is the threat of an asteroid hitting Earth, and is there anything we can do to prevent it from happening? Asteroid impacts are nothing new. Only last year, one exploded over the city of Chelyabinsk in Russia injuring 1500 people and damaging some 7,000 buildings.

"It was a pretty nasty event, luckily nobody was killed, but it just shows the sort of force that these things have," says Alan Harris, Senior Scientist, DLR Institute of Planetary Research Berlin.

While there was surprise nobody saw it coming, the asteroid itself wasn't that big, measuring no more than 20 metres across. It was tricky to spot, arriving into Earth's atmosphere backlit by the Sun.

In fact, much bigger threats lurk out in space. Just a few days ago another asteroid 270 metres wide passed near Earth. That kind of object could cause much more damage.

"Something with the size of a hundred metres for instance, which still isn't very big, you're talking about something that would fit into a football field, and that could actually completely destroy an urban area in the worst case. So those are the things that we're really looking out for, and that we're trying to find ways to tackle," says Harris.

Action to address the asteroid threat is already underway. Earlier in February, space scientists and policy experts from all the major space-faring nations held talks to create a framework for action. . . .

Thursday, November 14, 2013

Alien Life May Thrive in Impact Craters


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http://www.theufochronicles.com/2013/11/alien-life-may-thrive-in-impact-craters.html

By Amanda Doyle
Astrobiology Magazine
11-13-13

      An asteroid or comet smashing into the surface of a planet can spell doom for living creatures, but if the impact isn't large enough to completely decimate a planet's inhabitants, then the crater can ultimately provide a habitat for life. That's the finding of a new study reported at the European Planetary Science Congress in September by Iain Gilmour of the Open University in the United Kingdom.

If an ice- or water-rich area is the victim of an impact, the combination of heat and groundwater will create what is known as a hydrothermal system. In addition, many complex organic compounds, which could be precursor molecules for life, are created at high temperatures such as those generated by a collision. This combination could create the ingredients needed for life as we know it, making impact-induced habitats a potential candidate for the birthplace of life on Earth.

For a habitat within a crater to remain "home sweet home," there must be a constant supply of water and nutrients. The lifetime of the hydrothermal system is also crucial, as the heat from the impact will eventually fade away into its surroundings. . . .

Thursday, August 15, 2013

NASA Maps Dangerous Asteroids That May Threaten Earth


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NASA Maps Dangerous Asteroids That May Threaten Earth

By Tariq Malik
www.space.com
8-14-13

      If you've seen films like "Armageddon," you know the potential threat asteroids can be for Earth. To meet that threat, NASA has built a map like no other: a plot of every dangerous asteroid that could potentially endanger our planet … at least the ones we know about.

NASA released the new map of "potentially hazardous asteroids" on Aug. 2 in a post to its online Planetary Photojournal overseen by the agency's Jet Propulsion Laboratory in Pasadena, Calif. The map shows the orbital paths of more than 1,400 asteroids known creep too close to Earth for comfort. None of the asteroids mapped pose an impact threat to Earth within the next 100 years, agency officials said.

"These are the asteroids considered hazardous because they are fairly large (at least 460 feet or 140 meters in size), and because they follow orbits that pass close to the Earth's orbit (within 4.7 million miles or 7.5 million kilometers)," NASA officials explained in the image description. . . .

Saturday, February 23, 2013

Why Has The Knowledge of Earth-Bound Space Objects Been Classified 'Secret'?


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Military Hush-Up: Incoming Space Rocks Now Classified

Military Hush-Up: Incoming Space Rocks Now Classified

By Leonard David
SPACE.com
Originally Published
6-10-09
     For 15 years, scientists have benefited from data gleaned by U.S. classified satellites of natural fireball events in Earth's atmosphere – but no longer.

A recent U.S. military policy decision now explicitly states that observations by hush-hush government spacecraft of incoming bolides and fireballs are classified secret and are not to be released, SPACE.com has learned.

The satellites' main objectives include detecting nuclear bomb tests, and their characterizations of asteroids and lesser meteoroids as they crash through the atmosphere has been a byproduct data bonanza for scientists.

For 15 years, scientists have benefited from data gleaned by U.S. classified satellites of natural fireball events in Earth's atmosphere – but no longer.

A recent U.S. military policy decision now explicitly states that observations by hush-hush government spacecraft of incoming bolides and fireballs are classified secret and are not to be released, SPACE.com has learned.

The satellites' main objectives include detecting nuclear bomb tests, and their characterizations of asteroids and lesser meteoroids as they crash through the atmosphere has been a byproduct data bonanza for scientists.

The upshot: Space rocks that explode in the atmosphere are now classified.

"It's baffling to us why this would suddenly change," said one scientist familiar with the work. "It's unfortunate because there was this great synergy…a very good cooperative arrangement. Systems were put into dual-use mode where a lot of science was getting done that couldn't be done any other way. It's a regrettable change in policy."

Scientists say not only will research into the threat from space be hampered, but public understanding of sometimes dramatic sky explosions will be diminished, perhaps leading to hype and fear of the unknown. . . .

* Special Thanks To Andrew Ackerley