Orientation of the sail cone and clock angles. Image: arXiv:1108.3183v1 [astro-ph.IM]

(PhysOrg.com) -- Chinese scientist Shengping Gong and associates at Tsinghua University in Beijin have proposed an alternative method of deflecting the asteroid Apophis to ensure that it does not strike the earth. They believe that rather than just blowing it up ala the European Space Agency’s Don Quijote project, a better approach would be to use a solar sail, as described in their paper on the preprint server arXiv, to slowly nudge the asteroid off its trajectory just enough to keep it from bothering us here on Earth.

Apophis is approximately 880 feet in diameter and weighs an estimated 46 million tons. If it were to strike the earth, it would most certainly cause damage for thousands of miles around the epicenter, but wouldn’t spell doom for the planet as a whole.

First discovered in 2004 by Roy Tucker, David Tholen and Fabrizio Bernardi at the Kitt Peak National Observatory, Apophis was after initial study, thought to have a possibility of hitting the ; then after further study, it appeared that an impact was unlikely. Then later it was noted that when Apophis makes a close approach in 2029, there is a possibility that it could pass through what is known as a “keyhole” (a small gravitational zone near enough a planet to alter the course of an object) near our planet that could cause the next pass, in 2036, to hit us. Because of the dizzying number of variables involved in such a scenario, however, there appears to be differing views as to the probability of that actually happening. There also seems to be some disagreement as to the origin of its name; some suggest that Apophis comes from the ancient Egyptian deity, enemy of the uncreator Ra, Apep. Others suggest it’s simply a nod to the character Apophis on the television show Stargate SG-1.

In either case, Gong et al, propose using a space vehicle propelled by a solar sail that would move in a retrograde (opposite) orbit relative to Apophis fast enough so that when the collision occurred (like two cars running head on into each other on a freeway) the vessel would strike the asteroid moving at a relative speed of some 55 miles per second, enough they say, to push the offending off its current path.

The problem is, as the Chinese group readily admit, is in being precise enough in aiming the vessel. With all the variables at play (including the years it would have to travel) it would seem an almost impossible task. Nonetheless, the team seems undaunted, suggesting that such a vehicle could be built and launched in the time frame available.

More information: Utilization of H-reversal Trajectory of Solar Sail for Asteroid Deflection, Shengping Gong, Junfeng Li, Xiangyuan Zeng, arXiv:1108.3183v1 [astro-ph.IM] http://arxiv.org/abs/1108.3183

Abstract
Near Earth Asteroids have a possibility of impacting with the Earth and always have a thread on the Earth. This paper proposes a way of changing the trajectory of the asteroid to avoid the impaction. Solar sail evolving in a H-reversal trajectory is utilized for asteroid deflection. Firstly, the dynamics of solar sail and the characteristics of the H-reversal trajectory are analyzed. Then, the attitude of the solar sail is optimized to guide the sail to impact with the object asteroid along a H-reversal trajectory. The impact velocity depends on two important parameters: the minimum solar distance along the trajectory and lightness number. A larger lightness number and a smaller solar distance lead to a higher impact velocity. Finally, the deflection capability of a solar sail impacting with the asteroid along the H-reversal is discussed. The results show that a 10 kg solar sail with a lead-time of one year can move Apophis out of a 600-m keyhole area in 2029 to eliminate the possibility of its resonant return in 2036.

Apophis is approximately 880 feet in diameter and weighs an estimated 46 million tons. If it were to strike the earth, it would most certainly cause damage for thousands of miles around the epicenter, but wouldn’t spell doom for the planet as a whole.

First discovered in 2004 by Roy Tucker, David Tholen and Fabrizio Bernardi at the Kitt Peak National Observatory, Apophis was after initial study, thought to have a possibility of hitting the ; then after further study, it appeared that an impact was unlikely. Then later it was noted that when Apophis makes a close approach in 2029, there is a possibility that it could pass through what is known as a “keyhole” (a small gravitational zone near enough a planet to alter the course of an object) near our planet that could cause the next pass, in 2036, to hit us. Because of the dizzying number of variables involved in such a scenario, however, there appears to be differing views as to the probability of that actually happening. There also seems to be some disagreement as to the origin of its name; some suggest that Apophis comes from the ancient Egyptian deity, enemy of the uncreator Ra, Apep. Others suggest it’s simply a nod to the character Apophis on the television show Stargate SG-1.

In either case, Gong et al, propose using a space vehicle propelled by a solar sail that would move in a retrograde (opposite) orbit relative to Apophis fast enough so that when the collision occurred (like two cars running head on into each other on a freeway) the vessel would strike the asteroid moving at a relative speed of some 55 miles per second, enough they say, to push the offending off its current path.

The problem is, as the Chinese group readily admit, is in being precise enough in aiming the vessel. With all the variables at play (including the years it would have to travel) it would seem an almost impossible task. Nonetheless, the team seems undaunted, suggesting that such a vehicle could be built and launched in the time frame available.

More information: Utilization of H-reversal Trajectory of Solar Sail for Asteroid Deflection, Shengping Gong, Junfeng Li, Xiangyuan Zeng, arXiv:1108.3183v1 [astro-ph.IM] http://arxiv.org/abs/1108.3183

Abstract
Near Earth Asteroids have a possibility of impacting with the Earth and always have a thread on the Earth. This paper proposes a way of changing the trajectory of the asteroid to avoid the impaction. Solar sail evolving in a H-reversal trajectory is utilized for asteroid deflection. Firstly, the dynamics of solar sail and the characteristics of the H-reversal trajectory are analyzed. Then, the attitude of the solar sail is optimized to guide the sail to impact with the object asteroid along a H-reversal trajectory. The impact velocity depends on two important parameters: the minimum solar distance along the trajectory and lightness number. A larger lightness number and a smaller solar distance lead to a higher impact velocity. Finally, the deflection capability of a solar sail impacting with the asteroid along the H-reversal is discussed. The results show that a 10 kg solar sail with a lead-time of one year can move Apophis out of a 600-m keyhole area in 2029 to eliminate the possibility of its resonant return in 2036.

http://www.physorg.com/news/2011-08-chinese-method-deflecting-aster...

 

Views: 83

"Destroying the New World Order"

TOP CONTENT THIS WEEK

THANK YOU FOR SUPPORTING THE SITE!

mobile page

12160.info/m

12160 Administrators

 

Latest Activity

cheeki kea posted a photo
1 hour ago
cheeki kea commented on cheeki kea's photo
Thumbnail

First World Order

"Ah ha Truth hidden in plane sight. Notice the map depicted on this 'world order' book…"
1 hour ago
cheeki kea commented on cheeki kea's video
4 hours ago
cheeki kea posted a video

Iyah May Karmageddon Lyric Music Video

While ‘Karmageddon’ has sparked significantconversation and controversy, Iyah has stood her ground. She refused to compromise her vision when asked to change...
4 hours ago
tjdavis posted a video

Steven Wilson - PERSONAL SHOPPER (Official Video)

"The song PERSONAL SHOPPER sits somewhere between being a love-letter to shopping (which I love to do!) and the uneasiness I feel about the more insidious si...
yesterday
Doc Vega posted blog posts
Monday
rlionhearted_3 posted photos
Monday
Burbia posted a photo
Monday
tjdavis posted a video

propaganda: DIVIDE & CONQUER (1942) - Warner Bros. vs Hitler

Not to be confused with the much drier Frank Capra film from 1943.A "Broadway Brevity", released August 1, 1942. Vitaphone #1022-1023A.Transferred from 16mm.
Sunday
Doc Vega posted blog posts
Friday
cheeki kea commented on cheeki kea's photo
Thumbnail

Thumbs down - ship gone.

" So this sort of stupidity has occurred before. Norway or NZ - Who did it better? Cast your…"
Dec 20
cheeki kea favorited Doc Vega's blog post The Last Meal
Dec 20
tjdavis favorited Sandy's photo
Dec 17
tjdavis favorited cheeki kea's photo
Dec 17
tjdavis favorited tjdavis's video
Dec 17
tjdavis posted photos
Dec 17
tjdavis posted blog posts
Dec 17
cheeki kea favorited tjdavis's video
Dec 17
cheeki kea commented on cheeki kea's photo
Thumbnail

Prime clown idiot of the year.

" Stay tuned this prime clown might just resign from his own circus as his Finance Minister…"
Dec 17
cheeki kea commented on cheeki kea's photo
Dec 17

© 2024   Created by truth.   Powered by

Badges  |  Report an Issue  |  Terms of Service

content and site copyright 12160.info 2007-2019 - all rights reserved. unless otherwise noted