Thursday, January 27, 2005

Sex and Society Aboard the First Starships - Tariq Malik

Humans will begin a voyage to the nearest star this century, a NASA researcher says. And the crew might more resemble a tribal society than the chain of command of traditional space missions. Procreation would be required: The crew that arrived would be descendents of those that left.

Geoffery A. Landis, of NASA's Glenn Research Center, predicts the first star trek aboard a laser-powered sail ship could begin within 50 years as new methods of space travel put interstellar flight within the grasp of our grandchildren.

"I think that ultimately we’re going to do it, it’s just a question of when and who," Landis told "Interstellar travel, actually colonizing space and terraforming a planet, this is the exploration that everybody seems to want to do."

Traditional means of space travel are too slow to push humans out of the solar system. Instead, Landis envisions ships with vast sails, propelled by laser light to about 10 percent the speed of light. Such a craft could make the 4.3 light-year trip to Alpha Centauri, the nearest star system, in about 43 years, though slowing down would be a problem. Stopping could take up to 100 years.

Society on a ship

Making such a long trip possible would require the use of a multi-generational crew of men and women, along with all the supplies they would need as a society.

John H. Moore, a professor of anthropology at the University of Florida, believes that for long-term space missions that could last more than one generation, a group of about 180 crewmembers of mixed gender would allow for procreation of the species and maintain genetic diversity. The social structure of such a crew, however, would be much different than those aboard today’s Space Shuttle.

"We would have to leave aside the military-style organization of a crew and instead follow a social structure along familial lines," Moore said in a telephone interview.

This type of organization mirrors those developed by small tribal groups on Earth, where elders and the basic bonds between parent and child contribute to a working society. Family ties, with the obvious seniority structure between parents, children and older and younger siblings, Moore said, can be used to "construct a division of labor to accomplish any kind of work, including the work required for space travel."

Freeze sperm, leave the men behind

Sending humans out into deep space over a period of generations probably means a one-way trip for those aboard, researchers say, and would require the development of reliable power sources and closed-loop life support systems. Landis has even suggested sending out crews consisting only of women to save on weight, replacing men with frozen sperm to insure reproduction later down the line.

But the gulf between astronauts on the Space Shuttle and colonists aboard a laser-propelled space ship is a big one. The technological hurdles of building a laser large enough (on the order of a 100 meters wide) in space, and designing a stable sail -- not to mention the spacecraft itself -- are not small.

"The laws of physics are on our side, but it’s a hard question to answer: is the technology going to be there?" Landis said, adding that to date, only a handful of scientists are thinking about ideas for advanced space exploration.

Destiny and a swelling Sun

Some scientists think interstellar space travel is an inevitable course for humans. Ultimately, the Sun will reach the end of its life, swell to the size of a red giant and swallow up the Earth in the process. If humanity didn’t reach out to the stars, all of its proverbial eggs would be in one basket.

"The Earth itself is not entirely a safe place," Landis said. "It would be a good thing for our survival if we lived on more than one planet."

Other researchers say that the human instinct of expansion and exploration are enough to drive men and women out of the solar system, with additional incentives including Earth applications for star-faring technology and the potential of finding life.

New advancements in technology are still needed to put humans on interstellar transports, but how to get there seems apparent. Over the last few years, researchers have used lasers to push miniature sails and even small craft. And the idea has been around for decades.

"As far as getting to the stars, well I don’t think there’s any other technology that we understand the physics of enough to do it," said Leik Myrabo, who directed laser sail research under the Interstellar Technology program of NASA’s Jet Propulsion Laboratory.

Myrabo’s team used lasers to push a small swatch of carbon mesh, sail material, on a pendulum using only the power of light. Over the course of the project, about one year, technology had advanced enough to produce superior sail materials.

Meanwhile, other scientists have not ruled out more fringe ideas of space travel. Since 1996, NASA’s Breakthrough Propulsion Physics Project - also run out of the Glenn Research Center - has looked into the possibility of faster-than-light methods of transportation, like that alluded to by Star Trek’s "warp drive."

"It’s only speculation right now, but it’s a worthwhile goal to shoot for," said Marc G. Millis, an aerospace engineer who managed the program through 2001. "I’m as willing to entertain the possibility that we can do it as I am to think we’ll learn a lot more valuable things by trying, than by not making the effort at all."

Tuesday, January 25, 2005

SOHO 1000 contest

Contest by NASA about when the 1000 comet will be discovered by SOHO ..

SOHO is a spacecraft which measures the activities on the Sun. It is not a comet hunter as people think it is. Though since it blocks most of the Sunlight it can look into places which cant be seen by naked eye using a telescope. Most of these coment discoveries are those which were at its closest point from the Sun .

Pics from SOHO are available from the net .. Google

Saturday, January 15, 2005

Titan's First images

Check this out. Saturn's moon Titan is in the limelight, as the Huygens probe has landed successfully on Titan and has started scientific data. It cant stay longer than 2 hours because of the hostile environment but it will give us clues to Titan. Titan is covered with a methane haze but what makes it important is the fact that it has a thick atmosphere and also it resembles a baby Earth. Earth would have been like that when it was young. Huygens data will be a most successful venture for ESA whose Mars mission didnt go as planned (reference Beagle 2). This will boost their morale for sure

PS- I was supposed to put in a post on Gravitational Microlensing. Will put it in soon


Friday, January 07, 2005

Vega Planetary System

With so many galaxies in our universe, and billions of stars that each galaxy holds, is there a chance that there is a planetary system out there as our solar system and it may have a Earth like planet revolving around it. With a tsunami like that some of you may be wondering what if earth is getting destroyed and we need a different planet. We will have to move. Sounds so sci-fi. So a good start would be to find a planetary system. Many of the DSN and also the Hubble and Chandra X-ray are trying to find such sol systems. One promising star would be Vega . Vega is a star in the constellation Lyra. This star is probably a 350 millions years old. Scientists have predicted a Jupiter and a Neptune sized planet around the star.
They predicted it on the basis of X-ray images of the gas clouds surrounding the star. Its seems to be concentrated around some point at some specified distance from Vega. This pattern can only happen when a planet is revolving around it. So are we relieved that there is some place we can go if Earth is destroyed. Not exactly.
Firstly Vega is some 25 light years away more or less. Mars takes us 4 months. We may die before we reach there. We don't have technology to fly at the speed of light. Technically its not possible because at that speed mass would be infinite.
Secondly we have to find a planet 7.1 Au nearly from Vega. That's the point where an Earth-sized planet should be present. And the biggest problem. Vega is 3 times in mass than the Sun and hotter so it will consume its fuel much faster than the Sun (nearly 650 million years). Consider the Sun is nearly 4.5 billions years old and still at half life. So by the time we reach Vega ( if we managed to) we got to look for alternatives right away. Huh!! Wicked.
But Vega gives us an excellent possibility of finding more planetary systems like ours. A recent scientific technology called gravitaional microlensing has provided us with excellent tool to search for such systems. This can also be used to find far-away galaxies. I will give a description of gravitational microlensing in my next post. Till then enjoy the links for Vega and the Lyra constellation. And also to refresh your memory Vega was the crux of the film "Contact" starring Jodie Foster.

Wednesday, January 05, 2005

Dooms Day .. Nah

Tuesday, January 04, 2005

Planetary Nebula

Imagine what will happen to our Sun in 5 billion years.Something close to this

Above is the image of a Cats Eye nebula. Its what we call as planetary nebula. This stellar gas formation and also the formation of supernova is what we call as the remnants of a dying star. Our Sun will also go through this kind of phase during which its temperature will increase nearly thousand times what we have right now (Red Giant) is what the term is and finally in after 10000 years of that phase will become a white dwarf with no fuel left for fission. It will be hot though.
Cats Eye Nebula is a remant of such a star which formed nearly a 1000 years ago. This nebula is nearly 3000 light years away and its the most complex and most beautiful planetary nebula out there. Its a hot topic of research because of its complex structure. Read about it here

Saturday, January 01, 2005

Comet Machholz

Comet Machholz is gonna be the spectacle for the New Year. Will be a treat for us Northern Hemisphere amateur astronomers, if we can hope it wont be all cloudy and snowing. The supposed peak is on Jan 5-6.
I still remember my grandmother saying us to take a bath after seeing such celestial events as Solar eclipse or seeing a meteroite or comet. " Its a bad omen" she said. Now she is one of the stars in the sky.

Comets are one of the most interesting things in the sky . Technically they are satellites of the Sun, but have a really long and elliptical orbit. Most of the COmets dwell in the Kuiper belt. Its beleived to be mostly made of ice, and the tail is actually Ice condensing leaving a trail behind it. It happens when it is close to the Sun. Many of the comets may never come back again. For me its all the more interesting .. panspermia .. I guess i used that word in every post yet. I believe in that theory so strongly.