Revolutionizing Awareness

helping humanity, make choices, more so through awareness, than ignorance

Posts Tagged ‘orbit’

Revealed: What our solar system would look like to alien astronomers

Posted by Admin on September 28, 2010

Charon compared with Eris, Pluto, Makemake, Ha...

Planets

http://www.dailymail.co.uk/sciencetech/article-1314880/Nasa-supercomputer-shows-solar-looks-like-alien-astronomers.html

By DAILY MAIL REPORTER
Last updated at 3:13 PM on 24th September 2010

Scientists have used a Nasa supercomputer to work out what our solar system would look like to alien astronomers searching for other planets.

New simulations have tracked the interactions of thousands of dust grains to how this view might have changed as our planetary system matured.

And astronomers hope that the new view could help them learn how to spot planets orbiting distant stars.

The dust originates in the Kuiper Belt, a cold-storage zone beyond Neptune where millions of icy bodies – including Plutoorbit the Sun.

These images, produced by computer models that track the movement of icy grains, represent infrared snapshots of Kuiper Belt dust as seen by a distant observe

These images, produced by computer models that track the movement of icy grains, represent infrared snapshots of Kuiper Belt dust as seen by a distant observe

Kuiper Belt objects occasionally crash into each other, and this relentless bump-and-grind produces a flurry of icy grains.

But tracking how this dust travels through the solar system is not easy because small particles are subject to a variety of forces in addition to the gravitational pull of the sun and planets.

The grains are affected by the solar wind, which works to bring dust closer to the sun, and sunlight, which can either pull dust inward or push it outward. Exactly what happens depends on the size of the grain.

‘Our new simulations also allow us to see how dust from the Kuiper Belt might have looked when the solar system was much younger,’ said Christopher Stark, Carnegie Institution for Science in Washington, D.C.

‘In effect, we can go back in time and see how the distant view of the solar system may have changed.’

‘The planets may be too dim to detect directly, but aliens studying the solar system could easily determine the presence of Neptune — its gravity carves a little gap in the dust,’ said Marc Kuchner, an astrophysicist at NASA’s Goddard Space Flight Centre, who led the study.

‘We’re hoping our models will help us spot Neptune-sized worlds around other stars.’

The models include the effects of collisions among grains. By ramping up the collision rate, the simulations show how the distant view of the solar system might have changed over its history

The models include the effects of collisions among grains. By ramping up the collision rate, the simulations show how the distant view of the solar system might have changed over its history

The particles also run into each other, and these collisions can destroy the fragile grains. A paper on the new models, which are the first to include collisions among grains, appeared in the Sept. 7 edition of The Astronomical Journal.

‘People felt that the collision calculation couldn’t be done because there are just too many of these tiny grains too keep track of,’ Kuchner said. ‘We found a way to do it, and that has opened up a whole new landscape.’

With the help of NASA’s Discover supercomputer, the researchers kept tabs on 75,000 dust particles as they interacted with the outer planets, sunlight, the solar wind — and each other.

The size of the model dust ranged from about the width of a needle’s eye to more than a thousand times smaller, similar in size to the particles in smoke.

During the simulation, the grains were placed into one of three types of orbits found in today’s Kuiper Belt at a rate based on current ideas of how quickly dust is produced.

From the resulting data, the researchers created synthetic images representing infrared views of the solar system seen from afar.

‘One thing we’ve learned is that, even in the present-day solar system, collisions play an important role in the Kuiper Belt’s structure,’ Stark said.

That’s because collisions tend to destroy large particles before they can drift too far from where they’re made. This results in a relatively dense dust ring that straddles Neptune’s orbit.

Advertisements

Posted in Anomalic Interferences | Tagged: , , , , , , , | Comments Off on Revealed: What our solar system would look like to alien astronomers

South side of Milky Way may protect us from cosmic rays and mass extinctions

Posted by Admin on June 14, 2010

Science Space

As the Earth’s solar system travels around the center of the Milky Way galaxy, it also wobbles up and down from the galaxy’s disc. U.S. scientists found that these swings take about 62 million years to complete—thus, may expose the Earth to higher doses of dangerous cosmic ray that may also cause mass extinctions.

One complete orbit around the Milky Way galaxy takes the solar system about 225 million years to complete. So, we go through about four of these cycles above and below the galactic plane during one orbit around the Milky Way. (The International Astronomical Union (IAU) defines the galactic plane as the plane that is contained within the equator of the Milky Way galaxy, with the center of the Milky Way being the origin of this galactic coordinate system.)

(Note: The cycling back and forth between the northern and southern sides of the galactic plane happens due to mass and gravity. When the solar system is on the northern side of the Milky Way plane, the galactic mass located in the southern part of the Milky Way uses its gravity to pull the solar system back down, and, likewise, the northern Milky Way mass pulls the solar system back up when it is on the southern side of the Milky Way.)

Robert Rohde and Richard Muller, of the Lawrence Berkeley National Laboratory (Berkeley, California) studied a massive amount of fossil data that covered an era of over 500 million years. From their research published in a 2005 issue ofNature, they surmise that living things on the Earth have been at their greatest risk of extinction every 62 million years or so for the past 542 million years.

Mikhail Medvedev and Adrian Melott at the University of Kansas (Lawrence, Kansas) linked their research with this 2005 study from Rohde and Muller. They stated that when the solar system is at its maximum distance from the galactic plane (about 230 light-years above the disc) during its travels on the north side of the Milky Way, then the Earth is at its greatest risk from a drop in biodiversity (another way to say mass extinctions).

So, according to their research, living in the south side of the galactic plane of the Milky Way may be safer for humans and all living things here on the Earth.

Medvedev and Melott state that high-energy particles called cosmic rays strike the Earth on their travels from a large cluster of galaxies in the direction of the Virgo constellation. The Milky Way galaxy is moving toward the Virgo constellation in the northerly direction (at a speed of about 200 kilometers per second). So, when the Earth’s solar system is on the north side of the Milky Way’s plane, we are being bombarded by more cosmic rays from the Virgo constellation. Thus, the greatest risk of mass extinctions occurs when the Earth’s solar system has swung as far north of the galactic plane as it can.

These cosmic rays hit and interact with the Earth’s atmosphere, which causes the formation of millions of energetic electrons and other particles. So, the more cosmic rays that hit the Earth, the more that these energetic particles could possibly cause various problems such as changes in weather and climate, damage to deoxyribonucleic acid (DNA) within humans and other animals, and mass extinctions. (DNA contains the genetic material that allows living organisms to develop and function.)

Medvedev and Melott state that mass extinctions may very likely correspond to peaks in cosmic rays when the Earth is at its maximum northerly distance from the galactic plane. By combining Medvedev and Melott’s research in cosmic rays and the solar system’s cycle above and below the Milky Way plane and Rohde and Muller’s fossil research with the 62-million-cycle of mass extinctions, many scientists are looking into the possibility that cosmic rays are responsible for biodiversity cycles, or mass extinctions.

So far, other researchers state that this connection between mass extinctions and cosmic rays has not been clearly established. Therefore, additional research will be performed. In fact, new gamma-ray observatories, which are to be launched into orbit in the near future, may help to decide the question.

Medvedev and Melott presented their results at the recent April meeting of the American Physical Society. They will also be publishing their results in the Astrophysical Journal.

http://www.itwire.com/science-news/space/11573-south-side-of-milky-way-may-protect-us-from-cosmic-rays-and-mass-extinctions

Posted in Uncategorized | Tagged: , , , , , , , | Comments Off on South side of Milky Way may protect us from cosmic rays and mass extinctions