TO BOLDLY GO WHERE NO MAN HAS GONE BEFORE
In 2006, NASA launched its fastest spacecraft to date, the New Horizons space probe. Traveling at 27,000 mph, its prime mission is to map the surface of our first distant world, Pluto, which is technically a dwarf planet. In July 2015, it will travel within 10,000 miles of the world, determine if it has rings of dust and gas, and determine if its moons have atmospheres or water ice, like similar moons in our system. It will use Jupiter’s gravity to sling shot it to Pluto. The probe, 8 ft wide, and 1025 lbs, will perform a five month reconnaissance mission of Pluto and Charon and the other two moons, Nix and Hydra. The probe uses Plutonium 238 fuel to power its nuclear generator, which converts the Plutonium’s heat energy to electricity. Some of the sites on Pluto to be investigated are to be named in honor of Star Trek characters, such as Kirk, Spock, and Sulu. After Pluto, it will continue into the kuiper belt until its fuel cell decays. Three other probes are already there, Pioneer 10, which is no longer functional, and Voyagers I and II which are expected to continue functional for 5 more years.
We know already, however, that Pluto and other exo-planets are cold, barren worlds. Too distant from the sun and colder than any other planets, they are not candidates for life. If we want to travel further, we will need to go faster and farther. It took nine years to get there, using the fastest method we know. How long would it take us to reach the nearest star-the answer is too long! We have to find a quicker way. Our nearest star, Proxima Centauri is 4.3 light years away. Even with a ram jet fusion propulsion system, it would take 40 years. But let’s just say for argument, that we put our astronauts in suspended animation for those 40 years. After they awoke, what would they find?
Before we answer that question, there are several factors that determine whether life is possible on a distant world; including the size and type of its sun, its distance from it, whether or not it has an atmosphere and magnetosphere, and so on. There are several different kinds of suns; too many too list. The ones most commonly associated with the possibility of Earth-like worlds are Yellow and Red Dwarfs. Yellow dwarfs are yellow suns, similar to own size, and red dwarfs are slightly smaller. This is not to say life is not possible around other stars, astronomers just don’t know yet. These types of suns sometimes have planets in the Goldilocks zone, which is in ratio with our own planet, and our sun, Sol.
Proxima Centauri is part of a three star system, and is sometimes called Alpha Centauri C, after Alpha Centauri A & B. This is our next store galactic neighbor, a small red dwarf, possibly containing three planets. These planets, however, would have to be close to their sun to gain any benefit from it, due to to cooler status of the star. They are likely smaller, rocky planets with little or no atmosphere, colder or hotter, depending on their location, and have no life. They have weaker magnetospheres, and smaller orbits. This, unfortunately, is also our destiny as our sun slowly becomes a yellow giant, then a white dwarf, and then dims until it dies and becomes a truly dead brown dwarf as well. Proxima at one time must have been much larger, like a red giant. It is slowly dying, and any life there would have to be on a planet closer to its own Goldilocks zone . It is believed that may someday be the fate of moons like Europa and Titan, as the sun gets hotter. If mankind is able to survive, we may be able to tap into this natural resource. It may simply be a matter of planet hopping until we get to Proxima, if its even there by then, and not also a brown dwarf.
Tomorrow, we will travel into the rest of the Centauri system, then on to the next nearest star system. We will definitely need some kind of propulsion system better than fusion, more likely antimatter or warp drive. Spock, you have the com, ahead warp 1! Here is today’s links:
THE NEXT STORE NEIGHBORS
As we have seen, our nearest neighbor is Proxima Centauri, a dim red dwarf star which probably doesn’t have any habitable worlds, and took us forty years to get to, using a ram jet fusion engine. Solar sails may take less time, but lose their power without a sun, or solar winds to assist it. But what about the next binary star system less than a light year away? Alpha Centauri A would take approximately another 5-7 yrs to reach, and is a yellow sun similar to our own. So why wouldn’t there be life, right?
Well, for one thing, binary systems are suns that revolve around one another, and A is too large a star for the habitable zone to be any closer than one billion miles, and that path would probably be in the same path as B, which is an orange dwarf. Even if that isn’t the case, the planet would have to be much further from Alpha Centauri A to have life. Alpha Centauri A & B appears as one star, and is the brightest in the southern hemisphere, and the third brightest in the night sky. The system is 4.37 light years away. NASA has believed recently that there may be one earth size planet, Alpha Centauri Bb, which is 6 million miles from the orange dwarf. The discovery hasn’t been confirmed yet. If it does exist, the surface temperature would be 1500 degrees, still too hot for us to colonize there. So where does that leave us?
Our next stop is Barnard’s star, another red dwarf, even dimmer than Proxima Centauri. In the Northern hemisphere, it is in the constellation of Ophiuchus, and isn’t visible with the naked eye. It is 12 billion years old, much older than our own. It is in its final stages, and will become a brown dwarf in about 10 billion years. It was the target for Project Daedulus, a study of fast unmanned travel to nearby star systems. In 10,000 years, if it survives, Pioneer 10 will pass within 3.8 light years. It will no longer be functional, however. It is nearly 6 light years from Earth, still reachable with fusion, but would take sixty years to reach. This system is no promise, either. There may be some rocky planets there, but if they were too close, their fate would be no different than the Earth size planet in the last star system. It was once believed gas giants orbited it, but that was later disproved. There is a possibility that there are at least three planets that orbit this star, possibly an ice water world like Europa, or a liquid water world with no moon. Either of these choices would still be a difficult world. This star was a favorite of the novel “Interstellar”, by Kip Thorne. Whether or not there is any truth to this belief is yet to be determined.
If we want to go farther, however, we’re going to need a warp drive. Even at warp 2, 10 times the speed of light it would get us to the alpha system in 5 months. We would then be able to reach Barnard’s star in just under 7 years. Not as fast as would like, but considerably faster than 10,000 or 40 years. Tuesday, we will move on to our next closest neighbor, Wolf 359, another red dwarf. We better find some kind of world soon, or this search might not be worth it. Until then, here are today’s links:
THE THREE DWARFS
As we move along through our galaxy, our next interstellar neighbors would be a binary brown dwarf system, Luhman 16 and WISE 0855-0214, and a tiny red dwarf called WOLF 359. The binary system will take about 7 months to get there at warp 1. The red dwarf will take closer to 8. The brown dwarfs are lifeless dead stars from long ago. There is one possible planet orbiting one of the brown dwarfs, but there is no life there, and it is another colonization dead-end.
WOLF 359 is a very dim, low mass red dwarf 7.8 light yrs away, in the constellation of Leo, and is one of the faintest stars in the sky, and is only visible with a large telescope. It gains its energy through convection, and its temperature is only a mere 2800 degrees, low enough for chemical compounds to form and survive. It is a flare star, and undergoes large bursts of X rays and gamma rays. It is a young star,and less than a billion years old. This is too young a star to have formed any planets, an even if it did, the planet would have to be so close that it would have no protection from radiation. WOLF 359 was the star used in Star Trek franchise as the sight of an epic battle with the Borg, a race of invading artificial intelligent beings. There has been no planets found here, either.
So where does that leave us? We have passed a handful of stars and found nothing; how far must we go? The answer is as far as it takes, as we will see with our next group of stars. Tomorrow, we will travel further to another red dwarf, and then to the brightest star(s) in the night sky, Sirius. Until tomorrow, here are the links of the day:
SIRIUS, THE DOG STAR
It is the brightest star in our night sky, is seen in the southeast and southwest skies, and named after the Greek word seirous, meaning “glowing” or “scorcher.” Also known as the dog star, because of its location in the constellation of Canis Major(The Greater Dog), it has been the subject of UFO speculation and legends, and has been used as a navigational tool for sailors for as long as they have traveled the oceans.
It is Sirius, a white star with a minor star orbiting it, and possibly a brown dwarf as well. Its distance from us is 8.6 light yrs away, about 9 months away at warp 2, and the distance between the two white stars can vary between 8.2 and 31.5 astronomical units. An astronomical unit is 93,000,000 miles, the distance that Earth is from the sun. Sirius A is twice as big as our sun, and Sirius B is just under the size of Earth. The Sirius system will increase in brightness over the next 60,000 years as it gets closer to our own solar system. Sirius B has mass equal to our sun, and was once a red giant, before collapsing into a white dwarf about 120 million years ago. Sirius A has a surface temperature of 17,000 degrees, 7000 degrees hotter than our own sun, and puts out 26 times more energy.
There has been great speculation that ancient aliens may have come from this star system. Egyptian history has claimed that some of their star gods came from here, and an ancient African tribe, called the Dogon, believed an a reptilian species came from Sirius B. This is all very interesting, but is it factual? Let’s look at some of the facts of this famous star system.
Sirius A has a habitable zone between 186,000,000 and 465,000,000 miles. It is a relatively young star system, only about 300 million years old. Any planet orbiting either star would be a young world with shallow seas, small land masses and would be volcanic. It would have a very thick, hot and wet atmosphere, and only small forms of bacterial life could exist there. Any life there would have to have at least one billion years to develop. Sirius B, the white dwarf is more likely a candidate, as the planets would be just as far to their sun, even though it puts off more energy than our own. The problem with life here is that there just isn’t enough time for it to develop, assuming scientists’ correlation of life here to other planets is accurate.
So, until we have significant proof that the Dogon was right, Sirius extraterrestrials are just a legend, and staple of science fiction writers. Writers have constantly used the Egyptian and Dogon stories as inspiration. Even in my own book, the Talokians have come from a star system in its vicinity. Tomorrow, we will travel even further into our galaxy to visit another red dwarf, Lalande 21185. Until tomorrow, here are today’s links:
IS ANYBODY OUT THERE?
As we have seen, finding a solar system in our own backyard can be a little difficult, but we shouldn’t give up quite just yet. There is a small dim red dwarf, Lalonde 21185, just 8.3 light years that looks a little closer to home. It is too faint to see with the naked eye, one of the galaxy’s oldest stars at 10 x 9 billion years old and has 50 % the Earth’s mass. It was the target of the optical Space Interometry Mission which was to detect planets that were as small as 3 times the Earth’s mass. It was confirmed in 1996 that there were indeed at least two gas giants in the system,maybe three, making it one of the first solar systems to have confirmed planets orbiting it. Although they are like Jupiter, extremely active and cold, it gave us the belief that there may be earth-like planets out there, if we could find them, and that most solar systems form the same way. The project was discontinued in November of 2010, due to lack of funding. In 20,000 years it will be half the distance it is to us now.
At 10.5 light years, there is a young orange dwarf star, less than a billion years old, called Epsilon Eridani. It is slightly smaller than our own sun, but has much more magnetic activity due to its young age. It is the fifth brightest star in the southern constellation of Eridanus. There is a lot of dust in the system, indicating the formation of a planetary system, and the Hubble telescope confirmed the existence of one Jupiter sized gas giant. Epsilon Eridani has often been the location of science fiction stories, including Foundations Edge, by Isaac Asimov, and Starburst, by Frederik Pohl, and the possible home of Vulcan from Star Trek.
Although it is highly unlikely that Lalonde 21185 will ever possess any earth-like worlds, the verdict is still undetermined whether Epsilon will possess them. It is a relatively young system, and orange dwarfs are ideal for creating planets within their habitable zones. Large gas giants help to deflect asteroids and comets, and it has been determined that this system does indeed contain two asteroid belts similar to our own.
Monday, we will head to the first star like our own, Tau Ceti. Could there be life there, or at least a water based world? All next week we will feature stars that Hubble and Kepler have determined have possible earth-like worlds. Until then, here are today’s links:
HUBBLE AND KEPLER’S SEARCH FOR LIFE
I extended my series one more day to summarize what scientists have discovered about life in our universe. One thing we’ve discovered is it isn’t easy to find, but it may be out there somewhere. We’ve discovered possible planets, but not likely habitable ones. So what have the experts discovered?
The first planet ever discovered by Hubble was a hot, Jupiter gas giant called 51 Pegasi b 20 years ago. Unfortunately, the Hubble space telescope ran into problems, and was only designed to pick up large gas giants, and not smaller Earth-like worlds. Enter the Kepler spacecraft, a piece of sophisticated hardware able to detect planets by their orbital paths around their suns. Built in 2009, it has confirmed over 1,004 planets, 8 of them less than 2.7 times the size of Earth, and possibly habitable. 6 of these worlds orbit sun-like stars, and 20% of sunlike stars probably host earth-size planets.
The first confirmed Earth-like world was found about a year ago, is called Kepler 186f, 500 light years away. Then there this Kepler 10c, which is the exception to the rule. It is 560 light year away, 17 times the size of Earth, about the size of a small gas giant, and circles a sun-like star. It is 11 billion years old, and is a water world, with no land, no surface weathering, and few minerals. Most rocky worlds don’t get this large, but now scientists are starting to rethink how planets form.
This of course, is too far for us to visit. Even at warp three, it would take us 18 years to reach it. Although this does not seem like a long trip, at warp speed it would still be very taxing voyage. Maintaining a warp drive that long would use an unbelievable amount of energy. But there is hope, because the device has also detected three worlds closer to our solar system that may be habitable. 13 light years away, there is a red dwarf star, Kapteyn’s star, 11.5 billion years old, that has two earth-like worlds orbiting it. Kapteyn b and c are both water worlds, both with possible iron cores. Kapteyn c is similar to the warmer b, but it is predicted that c is to o cold for habitable life. There is also Gliese 832c, which is the world closest to our own, 16 light years away.
So, even if we don’t get an answer from our neighbors, there is a possibility that life does exist elsewhere. Life would probably be different from here; there is no blueprint for evolution, Life evolves in its own way and its own time. We cannot rely on our own history completely to guide us through hypothesis. Which is the basis of our next series starting tomorrow-How did life evolve on Earth? Until then, here are the links: