Forumchem - Forum with AI(ALICE BOT & HAL9000) and TTS

More dificult for us, more easy for you
It is currently Fri Nov 24, 2017 2:32 pm

All times are UTC





Post new topic Reply to topic  Page 1 of 75
 [ 742 posts ]  Go to page 1, 2, 3, 4, 5 ... 75  Next
Author Message
 Post subject: Mars" Ancient Oceans: A Key To Understanding of Earth"s Evolution?
PostPosted: Thu Apr 23, 2009 10:38 pm 
Offline
User avatar

Joined: Thu Apr 02, 2009 11:08 am
Posts: 1686

Ancient_mars_2_2The climate of the Red Planet was once much warmer than it is today. Sulfur dioxide may have played a key role in the climate and geochemistry of early according to geo-scientists at Harvard and MIT.





quot;There is abundant evidence for a warmer climate, perhaps even a liquid
water ocean, early in Martian history, between 3.5 and 4 billion years
ago,quot; saysnbsp; Daniel Schrag,
professor of earth and planetary sciences and environmental science and
engineering at Harvard. quot;However, scientists have found it difficult to
reconcile this evidence with our understanding of how the climate
system is regulated on Earth.quot;



Over millions of years, the Earth"s climate has been controlled by
the carbon cycle and its effect on carbon dioxide, the main greenhouse
gas. On Earth, there is a balance between carbon dioxide vented from
volcanoes and chemical reactions with silicate rocks on the Earth"s
surface that remove carbon dioxide from the atmosphere and convert it
to calcium carbonate, commonly known as limestone. Scientists believe
that this balance has helped maintain Earth"s habitability over the
last 4 billion years.



On Mars, there is not enough volcanic activity today to maintain
this cycle. But this was not true some 4 billion years ago, when a
giant volcanic complex called Tharsis erupted over tens to hundreds of
millions of years — and also a time when evidence suggests had a
much warmer climate. However, this carbon cycle on early should
have produced vast quantities of limestone like on Earth, and yet
almost none has been found.



The new hypothesis points the finger at sulfur dioxide released by
volcanoes. Sulfur dioxide is a powerful greenhouse gas, like carbon
dioxide, and it is more reactive with silicate rocks than carbon
dioxide. On Earth, sulfur dioxide is rapidly oxidized to sulfate, and
then removed from the atmosphere. The researchers argue that the
atmosphere of early would have lacked oxygen, so sulfur dioxide
would remain much, much longer.



quot;The sulfur dioxide would essentially pre-empt the role of carbon
dioxide in surface weathering reactions,quot; says Itay Halevy, a Ph.D.
candidate in Harvard"s Department of Earth and Planetary Sciences, the first author of the report published in Science journal.
quot;The presence of even a small amount of sulfur dioxide in the
atmosphere would contribute to the warmer climate, and also prevent
limestone deposits from forming.quot;



In place of limestone, the authors predict that sulfur minerals
would form in any standing water on Mars. This may explain the
surprising finding of the rovers that have identified sulfur minerals
as an abundant component of Martian soils.



quot;We think we now understand why there is so little carbonate on Mars, and so much sulfur,quot; Halevy says.



quot;Our hypothesis may also be important for understanding the early
Earth,quot; Schrag says. quot;Before the origin of life, our atmosphere may
have looked much like early Mars. Sulfur dioxide may have had an
important role then as well.quot;



Posted by Casey Kazan.



Related Galaxy posts:



Movie of NASA"s Sites on for Future Landings amp; Search for Ancient Life
Exploration: Secrets of the Soil
Is There Life on Mars? NASA Goes Underground to Find Out
New Phoenix Mission Technology to Search for Life
Is there an Interplanetary Mars-Earth Microbe Shuttle?
quot;The Overview Effectquot;: Is Space Travel Next Step in Human Evolution?
Lonely Hearts of the Cosmos Revisited -NASA"s Phoenix Probe amp; the Search for Extraterrestrial Life



nbsp;



Link:



http://harvardscience.harvard.edu/node/20056




Source


Top
 Profile      
 
 Post subject: Welcome to the Crowded Universe: 32 New Exoplanets Found -Can Discovery of Earth"s Twin Be Far Behind
PostPosted: Wed Oct 21, 2009 4:27 am 
Offline
User avatar

Joined: Thu Apr 02, 2009 11:08 am
Posts: 1686

Earths twin HARPS is zooming in fast on the discovery of a Twin Earth: The latest batch of exoplanets announced yesterday comprises no less than 32 new discoveries. Including these new results, data from HARPS have led to the discovery of more than 75 exoplanets in 30 different planetary systems.

HARPS is the High Accuracy Radial velocity Planet Searcher at the ESO 3.6m telescope at La Silla in Chile"s Atacama Desert dedicated to the discovery of extrasolar planets. Due to its amazing precision, the search for small planets, those with a mass of a few times that of the Earth known as super-Earths and Neptune-like planets has been given a dramatic boost.

The HARPS consortium selected their target stars with extreme care, with several sub-programs aimed at looking for planets around solar-like stars, low-mass dwarf stars, or stars with a lower metal content than the Sun. The number of exoplanets known around low-mass stars so-called M dwarfs has also dramatically increased, including a handful of super Earths and a few giant planets challenging planetary formation theory

HARPS has facilitated the discovery of 24 of the 28 planets known with masses below 20 Earth masses. As with the previously detected super-Earths, most of the new low-mass candidates reside in multi-planet systems, with up to five planets per system.

In 1999, ESO launched a call for opportunities to build a high resolution, precise spectrograph for the ESO 3.6-metre telescope at La Silla, Chile. Michel Mayor, from the Geneva Observatory, led a consortium to build HARPS, which was installed in 2003 and was soon able to measure the back-and-forward motions of stars by detecting small changes in a star"s radial velocity as small as 3.5 km/hour, a steady walking pace. Such a precision is crucial for the discovery of exoplanets and the radial velocity method, which detects small changes in the radial velocity of a star as it wobbles slightly under the gentle gravitational pull from an (unseen) exoplanet, has been most effective method in the search for exoplanets.

In return for building the instrument, the HARPS consortium was granted 100 observing nights per year during a five-year period to carry out one of the most ambitious systematic searches for exoplanets so far implemented worldwide by repeatedly measuring the radial velocities of hundreds of stars that may harbour planetary systems.

The programme soon proved very successful. Using HARPS, Michael Mayor"s team discovered the first super-Earth (around Ara; ESO 22/04) in 2004; in 2006, the trio of Neptunes around HD 69830 (ESO 18/06); in 2007, Gliese 581d, the first super Earth in the habitable zone of a small star (ESO 22/07); and in 2009, the lightest exoplanet so far detected around a normal star, Gliese 581e (ESO 15/09). More recently, they found a potentially lava-covered world, with density similar to that of the Earth"s (ESO 33/09).

"These observations have given astronomers a great insight into the diversity of planetary systems and help us understand how they can form," says team member Nuno Santos.

"By targeting M dwarfs and harnessing the precision of HARPS we have been able to search for exoplanets in the mass and temperature regime of super-Earths, some even close to or inside the habitable zone around the star," says co-author Xavier Bonfils.

Casey Kazan

Image Credit: http://www.theogijzen.nl/images/earths%20twin.jpg

Source: ESO materials





Source


Top
 Profile      
 
 Post subject: Ares I-X Rocket: NASA Unveils its New Baby
PostPosted: Wed Oct 21, 2009 4:35 am 
Offline
User avatar

Joined: Thu Apr 02, 2009 11:08 am
Posts: 1686
Slender, 327-Foot Rocket is U.S."s 1st New Craft in 3 Decades; Set for Pivotal Test Launch in 1 Week




Source


Top
 Profile      
 
 Post subject: November 2009 Issue: Astronaut 3.0
PostPosted: Wed Oct 21, 2009 12:02 pm 
Offline
User avatar

Joined: Fri Apr 03, 2009 1:35 am
Posts: 2451
title=

Features


Inside Astronaut Boot Camp


What does it take to prep humans for a trip to an asteroid or a martian moon Starvation Isolation Recycling feces for food NASA"s newest astronauts begin a grueling training regimen this fall to find out

By Dawn Stover


PopSci"s Brilliant 10


Meet ten young geniuses shaking up science today. They"re helping to keep us healthy, prevent disasters, and make green energy cheaper than coal. Lucky for us, our future is in their capable hands


Personal Chemistry


Every day we"re exposed to thousands of man-made chemicals, some of which seep into our bodies and remain there for decades. What that means for our health, we don"t fully understand--but I subjected myself to a battery of new tests in search of answers. By Arianne Cohen


Green Dream: Custom-Made Aluminum Windows Save Money and Energy


The build continues, plus four green doors and windows to retrofit your own home


Headlines



What"s New



How 2.0



FYI



Megapixels





Source


Top
 Profile      
 
 Post subject: Fly yourself to the moon
PostPosted: Sat Oct 24, 2009 12:29 am 
Offline
User avatar

Joined: Thu Apr 02, 2009 10:45 am
Posts: 1711

On July 20, 1969, two human beings landed on the moon for the first time. Forty years later, that accomplishment still stands as an unmatched moment in the history of human exploration. It was a truly wondrous event that captured imaginations worldwide -- nearly a billion people (one quarter of the Earth"s population at the time) followed it moment-by-moment on live TV or radio, around the globe.

Today, on the 40th anniversary of the Apollo 11 landing, Google is proud to announce the release of Moon in Google Earth, bringing you one step closer to understanding the experience of standing on the moon. It brings the Apollo stories out of the history books, recreating them in an immersive and interactive 3D environment.

To see for yourself, all you need is Google Earth 5.0 (if you already have it, no upgrade is required). Just click the planet button on the top toolbar of Google Earth, and choose Moon. You"ll be flow to the Moon, at which point you have all the same usual Google Earth controls -- drag your mouse on the globe to fly around, and use the Layers panel in the lower-left corner to discover content. Double-click any Layers item to fly to it.


Each of the Apollo landing missions is chronicled in detail through pictures and stories. We"ve even embedded video footage from Spacecraft Films that covers the most well-known moments on the surface. There are also immersive lunar surface panoramas, composed of photos taken by the astronauts themselves, presented for the first time in a 3D "Street View" style interface:

The Human Artifacts layer contains locations and trivia on every robotic spacecraft that"s ever landed on or crashed into the moon. Those that did land successfully are represented by 3D models, such as Luna 9 from the USSR:

You can turn on the Historical Maps layer to see maps that NASA itself used in the Apollo missions. Or just fly around and explore the 3D terrain:

If you get lost, that"s no problem... just pull up the Guided Tours layer. There you"ll find author Andrew Chaikin (A Man on the Moon) and Apollo 11 astronaut and author Buzz Aldrin (Magnificent Desolation) co-narrating an immersive fly-through tour of the Apollo 11 landing site. Harrison H. Schmitt, Apollo 17 astronaut and Fusion Technology Institute faculty member, is also on hand to describe his experience as the only geologist to have walked on the Moon.


The tours are like a movie, but better... when you pause, you can actually look around with the camera! See the Google Earth User Guide for more info.

Moon in Google Earth was made possible by Google"s Space Act Agreement, which allowed NASA Ames researchers to help us develop much of its content. We"re also grateful to JAXA, Japan"s space agency, for donating a global terrain dataset of the Moon.

We hope that you enjoy Moon in Google Earth. Explore it today, in observation of the 40th anniversary of one of humanity"s finest moments.

Michael Weiss-Malik, Product Manager, Moon in Google Earth





Source


Top
 Profile      
 
 Post subject: NASA Lanches Unmanned Moon Rocket
PostPosted: Sun Oct 25, 2009 2:20 am 
Offline
User avatar

Joined: Thu Apr 02, 2009 11:08 am
Posts: 1686
This rocket launch follows Wednesday"s postponed shuttle launch.





Source


Top
 Profile      
 
 Post subject: Newly Discovered Network of Moon Tunnels Could House Lunar Colonists
PostPosted: Mon Oct 26, 2009 3:32 am 
Offline
User avatar

Joined: Thu Apr 02, 2009 11:08 am
Posts: 1686

The moon may be a harsh mistress, but lately she has been giving up her secrets. Scientists have spotted a deep hole in the lunar surface that goes at least 260 feet down and is believed to open into an underground tunnel more than 1,200 feet wide.


The discovery is powerful evidence for long, winding tunnels carved by lava beneath the lunar surface. Such tunnels, whose existence has long been hypothesized, could provide shelter for future astronauts or colonists against the harsh radiation and surface temperatures on the moon.


Previous signs of such tunnels only existed as surface features called rilles, which hinted at hollow lava tubes below. Researchers only found the hole by poring through images taken by Japan"s deceased Kaguya lunar probe.


Scientists told New Scientist that rubble or solidified lava may have blocked off much of the underground tube. But the Kaguya team continues to search for more openings, and NASA"s Lunar Reconnaissance Orbiter could also begin snapping new shots of the area that are 10 times sharper.


So let"s get this all straight. Water on the moon, check. Supergun concepts for space launches, check. And then there"s the underground tunnels for colonists. All we need now is a reality show: Robert Heinlein"s Survive the Moon.


[via New Scientist]



Source


Top
 Profile      
 
 Post subject: Climate Change Clues from the Solar Systems Largest Impact C
PostPosted: Mon Oct 26, 2009 8:02 am 
Offline
User avatar

Joined: Fri Apr 03, 2009 2:28 am
Posts: 1364
Climate Change Clues from the Solar Systems Largest Impact Craters (A Weekend Feature)


Wwwreuterscom_3The prehistoric Chicxulub crater left by an asteroid collision in Mexico"s Yucatan Peninsula could yield clues about what Mars was like billions of years ago, according to NASA planetary geologist Adriana Ocampo, who is studying buried deep under southeastern Mexico for hints about what impact craters can reveal about planet formation. Her work could shed light on a giant crater on the surface of Mars -the largest in the Solar System- that was created by an impact from an object the size of Pluto.

Astronomers have been puzzled for decades about a huge dent on the surface of Mars -- the largest known crater in the solar system -- and new evidence last month suggests it was caused by the impact of an asteroid the size of the moon.

The Mexican crater, known as Chicxulub, was created when an asteroid that smacked into Earth 65 million years ago in a catastrophe that wiped out around half the planet"s species and was perhaps responsible for the dinosaurs becoming extinct.

Studying the debris spewed by the collision may answer questions about radical changes in atmosphere that can result from massive asteroid hits, Ocampo, has been studying the Yucatan crater for a decade, told Reuters.

"It"s a natural laboratory because of its similarities to what we can find on other planets like Mars where humans can"t go," Ocampo said of Mexico"s smaller crater.

The crater on Mars, measuring 5,300 miles across, is so big that it has left half the planet at a lower elevation.

NASA"s Mars Reconnaissance Orbiter and Mars Global Surveyor have provided detailed information about the elevations and gravity of the Red Planet"s northern and southern hemispheres. A new study using this information may solve one of the biggest remaining mysteries in the solar system: Why does Mars have two strikingly different kinds of terrain in its northern and southern hemispheres The huge crater is creating intense scientific interest.

The mystery of the two-faced nature of Mars has perplexed scientists since the first comprehensive images of the surface were beamed home by NASA spacecraft in the 1970s. A giant northern basin that covers about 40 percent of Mars" surface, sometimes called the Borealis basin, is the remains of a colossal impact early in the solar system"s formation, the new analysis suggests. At 8,500 kilometers (5,300 miles) across, it is about four times wider than the next-biggest impact basin known, the Hellas basin on southern Mars. An accompanying report calculates that the impacting object that produced the Borealis basin must have been about 2,000 kilometers (1,200 miles) across.That"s larger than Pluto. It appears to have held an ocean in crater the size of the combined areas of Asia, Europe and Australia,the early days of the planet, before Mars lost so much of its atmosphere and the water either sublimated away or froze beneath the surface.

Mexico"s crater is a much smaller 100 miles in diameter and is now half a mile underground, where rocks and earth have buried it over millions of years. Space geologists believe the asteroid hit in the Caribbean Sea, probably causing a huge tsunami.

Information from Chicxulub could also give clues about whether or not there was water on the surface of Mars long after the planet was dented by the massive asteroid hit.

Scientists have detected frozen water on the surface of the red planet. Martian seas could have disappeared when the planet was bombarded by smaller meteors that changed its atmosphere and dried it out, Ocampo said.

Posted by Casey Kazan.

Related Galaxy posts:

Cataclysmic Clockwork -Our Solar System"s Deadly Orbit Through the Milky Way
Fragments of Ancient Earth to be found on Moon

Source Link

Link 1
Link 2





Source


Top
 Profile      
 
 Post subject: Fly to the Moon with Google Earth
PostPosted: Wed Oct 28, 2009 7:22 pm 
Offline
User avatar

Joined: Thu Apr 02, 2009 11:08 am
Posts: 1686
title=

Earthlings can celebrate 40 years since the first lunar landing by planting their virtual boots back on the moon in Google Earth. Or they can just swoop over the 3-D lunar landscape, Superman-style.


Google unveiled the new Moon in Google Earth feature today during a press conference in Washington, D.C. Those in attendance included female space tourist Anousheh Ansari, Apollo 11 astronaut Buzz Aldrin, and NASA officials.


Now"s as good a time as any to download Google Earth and dip into the lunar goodie bag, which includes historical moon charts used during astronaut training, 3-D exploration of the six Apollo landing sites, and a human artifacts layer that shows what people left behind. But if that"s all too overwhelming, you can also take guided lunar tours hosted by astronauts Buzz Aldrin and Harrison Schmitt.


Speaking of Aldrin, the 79-year-old astronaut told PopSci that he"d prefer Mars over the moon as NASA"s next destination. It"s also worth noting that Google Earth provided a full-fledged tour of Mars before getting to Earth"s lunar neighbor. Hint hint, NASA





Source


Top
 Profile      
 
 Post subject: Pacific-Ocean-Sized Explosion On Jupiter Highlights the Hawk
PostPosted: Wed Oct 28, 2009 11:44 pm 
Offline
User avatar

Joined: Thu Apr 02, 2009 11:08 am
Posts: 1686
Pacific-Ocean-Sized Explosion On Jupiter Highlights the Hawking "Asteroid" Theory

Jup-sl9-3 In further evidence that space itself is an action movie (or at least that God watches Michael Bay movies), an explosion the size of the Pacific ocean has scarred Jupiter. Yes, the entire ocean. The explosion occurred on July 19 when an asteroid slammed into the planet, and although Jupiter has no solid ground the gas can still get thick enough for things like "impacts" and "KABOOM" to happen.





The Jupiter impact event is another big red line underscoring Stephen Hawking"s theory that one of the major factors in the possible scarcity of intelligent life in our galaxy is the high probability of an asteroid or comet colliding with inhabited planets. We have observed, Hawking pointed out in his lecture Life in the Universe, the collision of a comet, Schumacher-Levi, with Jupiter (below), which produced a series of enormous fireballs, plumes many thousands of kilometers high, hot "bubbles" of gas in the atmosphere, and large dark "scars" on the atmosphere which had lifetimes on the order of weeks. The July 19th event is a weak second place, but still totally awesome (and awesome if projected to a planet called Earth).

One of the most interesting things about the explosion is that it was detected by an amateur astronomer. We might have a lot of super-slick space-searching sensors, but there"s still a hell of a lot more space to watch than we have equipment to watch it - which is why Australian hobbyist Anthony Wesley was the first to see it. The information spread online, and Berkeley astronomer changed his plans for pre-booked time on the Hawaiian Keck II telescope, abandoning his planet-hunting to get a closer look. A much cooler use of internet communications than tweeting about sandwiches.

The resulting scar on the surface of Jupiter shows up as a dark patch in visible light, but a very bright spot in infrared, caused by a radical rearrangement of gases in the region of the detonation. The bright spot will also allow scientists to examine the motion of gases in Jupiter"s atmosphere, test theories developed during past impacts, and generally think "Wow, this stuff we do is pretty awesome, isn"t it"

Many more tools will soon be brought to bear on this huge planetary event. Hubble will be getting in on the action, bringing its brand-new wide angle camera to bear, while Berkeley will be bringing laser guide stars to bear (artificial star-signals created in the atmosphere by laser beam, allowing the use of adaptive optic telescopes which can correct for the atmosphere"s effects on light). So even the tools being used to look at this are awesome.

As Stephen Hawking says, the general consensus is that any comet or

asteroid greater than 20 kilometers in diameter that strikes the Earth

will result in the complete annihilation of complex life - animals and

higher plants. (The asteroid Vesta, for example, one of the

destinations of the Dawn Mission, is the size of Arizona).

But back to Professor Hawking, he of black-hole radiation fame: How

many times in our galaxy alone has life finally evolved to the

equivalent of our planets and animals on some far distant planet, only

to be utterly destroyed by an impact Galactic history suggests it

might be a common occurrence. Our cold comfort comes from the adjective "galactic" -that"s a hugely different time perspective that our biblical three score and ten.

Luke McKinney

Stephen Hawking: "Asteroid Impacts Biggest Threat to Intelligent Life in the Galaxy"

The NEO Code -Earth"s Hotspots Most at Risk Of Getting Hit by an Asteroid


Jupiter Explosion





Source



Top
 Profile      
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 1 of 75
 [ 742 posts ]  Go to page 1, 2, 3, 4, 5 ... 75  Next

All times are UTC


Who is online

Users browsing this forum: ovkooelon529 and 10 guests


 
Search for:
 
Jump to:  

cron
Click me:
Powered by phpBB © 2000, 2002, 2005, 2007, 2008, 2009 phpBB Group
Chronicles phpBB3 theme by Jakob Persson. Stone textures by Patty Herford.
With special thanks to RuneVillage

This site have 4 type of tecnology in order to convert text to speech. By default you use the vozme tecnology. In order to know the other you need to sign for.


- Privacy Policy -