Showing posts with label Asteroids. Show all posts
Showing posts with label Asteroids. Show all posts

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, March 28, 2015

'Iron Rain' Bypasses the Moon to Fall Mostly on Earth?

'Iron Rain' Bypasses the Moon to Fall Mostly on Earth?

By Simon Redfern
University of Cambridge/
space.com
3-27-15

      New experiments show that the asteroids that slammed into Earth and the moon more than 4 billion years ago were vaporised into a mist of iron. The findings, published in Nature Geoscience, suggest that the iron mist thrown up from the high velocity impacts of these asteroids travelled fast enough to escape the moon’s gravity, but stayed gravitationally stuck on more massive Earth. And these results may help explain why the chemistry of the Earth and the moon differ.

When and how Earth’s metallic core formed is uncertain. Clues come from known differences in the preferences of certain elements incorporated in the silicate mantle or the metal core. In a mixture of silicate rock and iron metal, the atoms of certain elements, such as gold and platinum, tend to prefer to enter the metal, while others, such as hafnium, prefer the silicate.

As Earth’s iron-rich core formed it “sucked” the metal-loving elements out of the planet’s rocky mantle. . . .

Friday, August 01, 2014

Early Life on Earth Likely 'Sanitized,' New Study Suggests

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Early Life on Earth Likely 'Sanitized,' New Study Suggests

Rain of asteroids melted early Earth, boiled its oceans, study shows

By Julia Rosen
www.latimes.com
7-30-14

      When you look up at the moon’s pockmarked face, you’re actually staring at Earth’s early history. The rain of asteroids that pummeled the lunar surface hit our planet too — it’s just that erosion and plate tectonics blotted out the evidence. In fact, no rocks anywhere in the world survived to tell the story of the first 500 million years of Earth’s 4.5-billion-year existence, a tumultuous period of frequent impacts known darkly as the Hadean.

Now, scientists have capitalized on the moon’s long memory to uncover Earth’s own past. The researchers found that much of our planet’s surface probably melted repeatedly following large collisions during the Hadean eon. Some of these impacts likely vaporized the oceans and sanitized the planet of any early life that may have gained a foothold, according to a new study published Wednesday in the journal Nature. . . .

Tuesday, April 29, 2014

Dark Matter Could Send Asteroids Crashing into Earth


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Dark Matter Could Send Asteroids Crashing into Earth

By Charles Q. Choi
Space.com
4-28-14

      Dark matter could sling lethal meteors at Earth, potentially causing mass extinctions like the cataclysm that ended the Age of Dinosaurs, Harvard scientists say.

Physicists think the mysterious, invisible substance called dark matter makes up five-sixths of all matter in the universe. It was first detected by the strength of its gravitational pull, which apparently helps keep the Milky Way and other galaxies from spinning apart, given the speeds at which they whirl.

Scientists have recently suggested that a thin, dense disk of dark matter about 35 light-years thick lies along the central plane of the Milky Way, cutting through the galaxy's disk of stars. The sun travels in an up-and-down, wavy motion through this plane while orbiting the center of the galaxy.

Researchers suggest this disk of clouds and clumps made of dark matter might disturb the orbits of comets in the outer solar system, hurling them inward. This could lead to catastrophic asteroid impacts on Earth, of the kind that likely ended the Age of Dinosaurs . . ..

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. . . .

Tuesday, September 17, 2013

Asteroid Grand Challenge: NASA's Request for Help To Combat Asteroid Threat | VIDEO


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Asteroid Grand Challenge – NASA's Request for Help To Combat Asteroid Threat

NASA Asking 'Makers' to Help Combat Asteroid Threat

By Miriam Kramer
www.space.com
9-17-13

      NASA continues to broaden its search for ideas that could help prevent killer asteroids from striking Earth.

Agency officials will attend the World Maker Faire in New York City this weekend (Sept. 21-22), with the goal of convincing the global community of inventors and tinkerers to help discover, track and deflect asteroids that could put Earth in peril.

At Maker Faire, NASA will highlight its "Asteroid Grand Challenge," a call for ideas from the public, industry and academia that the space agency unveiled this past June.

"Unlike traditional NASA missions of exploration and science, this grand challenge is driven by the idea that protecting our planet is an issue bigger than any one program, mission or country," NASA chief technologist Mason Peck said in a statement.

"For the first time, NASA has reached out to industry, academia, stakeholder organizations and private citizens for ideas on how to find, track and deflect asteroids," Peck added. "These partnerships represent a new way of doing business for NASA and a call to action for makers: join us to become a critical part of the future of space exploration." . . .

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