2 big satellites collide 500 miles over Siberia

Question: What happens when you get 2 man made satellites in space collide with each other?

Chaos?

More debris in the space?

Okay, for those who are mathematically inclined, when you have two big objects, one weighing 560kg (about 1235 pounds after a quick check to google) and 1 tonne (1000 kg) and both are travelling at high speeds (but not at relativistic) collide with each other. (Maybe you can refer to here about inelastic collision ) Will conservation of momentum (here )as well as the conservation of kinetic energy still hold?

If not, why?

How about doing a simulation to model it? :D

I just read the news:

2 big satellites collide 500 miles over Siberia (Update)
February 11th, 2009

(AP) -- Two big communications satellites collided in the first-ever crash of two intact spacecraft in orbit, shooting out a pair of massive debris clouds and posing a slight risk to the international space station.


NASA said it will take weeks to determine the full magnitude of the crash, which occurred nearly 500 miles over Siberia on Tuesday.

"We knew this was going to happen eventually," said Mark Matney, an orbital debris scientist at Johnson Space Center in Houston.

NASA believes any risk to the space station and its three astronauts is low. It orbits about 270 miles below the collision course. There also should be no danger to the space shuttle set to launch with seven astronauts on Feb. 22, officials said, but that will be re-evaluated in the coming days.

The collision involved an Iridium commercial satellite, which was launched in 1997, and a Russian satellite launched in 1993 and believed to be nonfunctioning. The Russian satellite was out of control, Matney said.

The Iridium craft weighed 1,235 pounds, and the Russian craft nearly a ton.

No one has any idea yet how many pieces were generated or how big they might be.

"Right now, they're definitely counting dozens," Matney said. "I would suspect that they'll be counting hundreds when the counting is done."

As for pieces the size of micrometers, the count will likely be in the thousands, he added.

There have been four other cases in which space objects have collided accidentally in orbit, NASA said. But those were considered minor and involved parts of spent rockets or small satellites.

Nicholas Johnson, an orbital debris expert at the Houston space center, said the risk of damage from Tuesday's collision is greater for the Hubble Space Telescope and Earth-observing satellites, which are in higher orbit and nearer the debris field.

At the beginning of this year there were roughly 17,000 pieces of manmade debris orbiting Earth, Johnson said. The items, at least 4 inches in size, are being tracked by the U.S. Space Surveillance Network, which is operated by the military. The network detected the two debris clouds created Tuesday.

Litter in orbit has increased in recent years, in part because of the deliberate breakups of old satellites. It's gotten so bad that orbital debris is now the biggest threat to a space shuttle in flight, surpassing the dangers of liftoff and return to Earth. NASA is in regular touch with the Space Surveillance Network, to keep the space station a safe distance from any encroaching objects, and shuttles, too, when they're flying.

"The collisions are going to be becoming more and more important in the coming decades," Matney said.

Iridium Holdings LLC has a system of 65 active satellites which relay calls from portable phones that are about twice the size of a regular mobile phone. It has more than 300,000 subscribers. The U.S. Department of Defense is one of its largest customers.

The company has spare satellites, and it is unclear whether the collision caused an outage. An Iridium spokeswoman had no immediate comment.

Initially launched by Motorola Inc. in the 1990s, Iridium plunged into bankruptcy in 1999. Private investors relaunched service in 2001.

Iridium satellites are unusual because their orbit is so low and they move so fast. Most communications satellites are in much higher orbits and don't move relative to each other, which means collisions are rare.

Iridium Holdings LLC, is owned by New York-based investment firm Greenhill & Co. through a subsidiary, GHL Acquisition Corp., which is listed on the American Stock Exchange. The shares closed Wednesday down 3 cents at $9.28.

AP science writer Seth Borenstein in Washington and AP technology writer Peter Svensson in New York contributed to this report.


- http://www.physorg.com/news153649979.html

- wong chee tat :)

Thoughts and Rocky discusses Life with his son

Let us view the video first:




"The world ain't all sunshine and rainbows. It's a very mean and nasty place...

and I don´t care how tough you are, it will beat you to your knees and keep you there permanently,

if you let it. You, me or nobody, is gonna hit as hard as life. But ain't about how hard you hit...

It's about how hard you can get hit, and keep moving forward... how much you can take, and

keep moving forward. That´s how winning is done. Now, if you know what you worth, go out and

get what you worth. But you gotta be willing to take the hits. And not pointing fingers saying:

You ain´t what you wanna be because of him or her or anybody.

Cowards do that and that ain´t you! You´re better than that!"

Let's look at the slightly longer version:



Thanks to the person who share this portion of the video.

Okay, after looking at this video.

What do you think? What are your thoughts on this?

Does this propel us to work harder? Or not?

- wong chee tat :)

New Windows virus attacks PHP, HTML, and ASP scripts

New Windows virus attacks PHP, HTML, and ASP scripts
 
Virus gets around

By Dan Goodin in San Francisco  

Posted in Security, 12th February 2009  

Researchers have identified a new strain of malware that can spread rapidly from machine to machine using a variety of infection techniques, including the poisoning of webservers, which then go on to contaminate visitors.

The malware is a variation of a rapidly mutating virus alternately known as Virut and Virux (And here too ). It has long proved adept at injecting itself into executable files, which are then able to attack uninfected machines through network drives and USB sticks.

The variant, which Microsoft is calling Virus:Win32/Virus.BM, is also able to infect web scripts based on languages such as PHP, ASP, and HTML. Servers that become infected include an iframe in webpages that attempt to spread malware to visitors.

"This catapults the possibility of spreading even farther," Trend Micro researchers warn. "If the script files happen to be uploaded to a publicly accessible website, any visitor to the affected sites will be led to the URL embedded in the iframe code."

The iframe surreptitiously directs visitors to zief.pl (don't visit it unless you're a security professional), which attempts to exploit a variety of vulnerabilities based on the browser and other applications the user has installed, Microsoft researchers say. Once installed, the virus injects its code into various system processes such as explorer.exe and winlogon.exe and hooks low-level Windows APIs to ensure it stays in memory.

The virus has also picked up some new polymorphic tricks designed to make it harder for anti-virus programs to detect. Among other things, it uses more than one layer of encryption, allowing its binary fingerprint to change but to preserve its malicious payload.

Infected machines will have an IRC backdoor installed that tries to connect to several servers using port 80. ®

- http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=PE_VIRUX.A

- http://www.theregister.co.uk/2009/02/12/new_virut_strain/

- http://www.symantec.com/security_response/writeup.jsp?docid=2006-051402-1930-99

- wong chee tat :)