http://thespacereporter.com/2015/04/first-exoplanet-seen-with-reflected-visible-light/ By Kathy Fey , The Space Reporter | April 22, 2015 An exoplanet known as 51 Pegasi b has been detected with visible light a first in the history of space observation beyond our solar system. This achievement of capturing a visible-light spectrum image from 50 light-years out may hail a new era of similar observations of faraway planets. According to Discovery News, astronomers used the HARPS component on the European Southern Observatorys 3.6-meter telescope, located at the La Silla Observatory in Chile, to capture the image. The planet that scientists observed is a type known as a hot Jupiter a gas giant that orbits relatively close to its parent star. 51 Pegasi b was first spotted in 1995, gaining the distinction of being the first planet discovered beyond our solar system that orbited a Sun-like star. The most recent data collected by scientists suggests that the exoplanet is slightly larger than Jupiter but about half as massive, and it has a highly reflective surface. Since the initial discovery of 51 Pegasi b, over 1900 exoplanets have been found, but until now, astronomers could not observe the features of those planets in the visible light spectrum. Scientists most commonly gather data regarding an exoplanets atmosphere by waiting until the planet passes in front of its parents star and then observing how the stars light spectrum is filtered as it passes through the planets atmosphere a technique called transmission spectroscopy. As outlined in a EurekAlert report, another method of detecting just the temperature of an exoplanet is to view it when on the far side of its star. The new method of observation employed with the HARPS instrument, however, does not rely on planetary transit, and it reveals planetary characteristics not detectable by other methods. Scientists are impressed with the ability of the HARPS instrument to pick up the planets reflected light despite the planets dimness relative to the nearby star and despite other sources of interstellar interference. This type of detection technique is of great scientific importance, as it allows us to measure the planets realmass and orbital inclination, which is essential to more fully understand the system. It also allows us to estimate the planets reflectivity, or albedo, which can be used to infer the composition of both the planets surface and atmosphere. Jorge Martins of the European Southern Observatory said. The HARPS instrument has a limited range of use for this planet-spotting technique, and the fact that it performed so well is highly promising. Larger telescopes such as ESOs Very Large Telescope and the European Extremely Large Telescope could reveal much more about the many exoplanets scattered throughout the galaxy. --------------------- Awesome! This is a real milestone!
Innit? I wish someone would send a near-light-speed probe out to a neighboring system to get close-ups. I think it's theoretically possible to get a probe going that fast with ion propulsion, and at that speed it should actually get to its destination in just a matter of years or decades. Of course, I'm no expert in astrophysics and could be way off-base..
Same here. I recall studying books in my elementary school years in which Mars featured as huge and mysterious and theoretically reachable . . . and I would have dreams about going there in a space ship. Sigh.
Speaking of which, it sounds like Mars One might be a scam. It certainly doesn't sound promising from what one finalist for the program has said. http://www.iflscience.com/space/whats-going-mars-one Mars One Finalist Announces That It's All A Scam March 22, 2015 | by Janet Fang Earlier this week, a colonist candidate for the one-way mission to Mars broke his silence and spoke out against the Mars One project, calling the selection process dangerously flawed. After filling out an application (mostly out of curiosity), former NASA researcher Joseph Roche, now of Trinity College, became one of 100 finalists to live in permanent settlement on Mars. In his interview with Elmo Keep for Medium, Roche expressed many concerns, ranging from inaccurate media coverage (there were only 2,761 applicants, not 200,000) to Mars One’s psychological or psychometric testing (or lack thereof) to how leading contenders earned their spot (he says they paid for it). “When you join the ‘Mars One Community,’ which happens automatically if you applied as a candidate, they start giving you points,” Roche explains. “You get points for getting through each round of the selection process (but just an arbitrary number of points, not anything to do with ranking), and then the only way to get more points is to buy merchandise from Mars One or to donate money to them.” And if media outlets offer payment for an interview, the organization would like to see 75 percent of the profit. As a result the most high-profile hopefuls, he says, are those who brought about the most money. So far, he’s completed a questionnaire, uploaded a video, got a medical exam, took a quick quiz over Skype, and… not too much else, it seems. Despite making the final 100, Roche has never met anyone from Mars One in person. A planned multiday, regional interview seems to have been cancelled. There are other bad signs for Mars One. The organization’s contract with production company Endemol is no longer in place; Mars One was hoping to generate $6 billion from a reality show. And a former adviser to the project, theoretical physicist Gerard Hooft, said a realistic launch date isn’t 10 years from now -- it’s 100 years. Now, Mars One CEO Bas Lansdorp has responded in a video [transcript], where he says a lot of the bad press is untrue. “There are a lot of current round three candidates that did not make any donations to Mars One and there are also lot of people that did not make it to the third round that contributed a lot to Mars One,” he says. “The two things are not related at all and to say that they are is simply a lie.” Lansdorp maintains that there were indeed 200,000 applications, and that criticism by the organization’s advisers is valued because it helps improve their mission. Their next step, he says, is to find out which of the candidates “have what it takes” through more thorough selection processes, team and individual challenges, and longer interviews. They’re also in talks with another production company. And as far as the delays are concerned, he says, “is it really a failure if we land our first crew two, four, six, or even eight years late?” ------------------- I particularly like the bit about having to buy merchandise or make donations to get more points. I'll bet this thing won't fly and a lot of people will be out a lot of money, kind of like what happens all too often on Kickstarter.
Amen! The "no returns" policy does bother me from an ethical point of view - regardless of the selection process.
There are huge issues with doing this. For example the energy required to get anything to near-light speed is huge. Then if the probe hits a small grain of dust on the way it is good bye probe. If the technique in the OP works then many more planets will be found. Not many planets go between us and their sun. Just think how often Venus comes between us and the sun and that would happen a lot more often that planets around other stars.
True enough, but then optics are always very limited. Look at the best image Hubble is able to get of the more distant objects in our own solar system for instance. We get a few pixels of Pluto that way, while New Horizons is now already capturing better images when it has another 3 months to go before it even reaches and zooms past that world and its satellites. Getting a probe to another star system would be SUCH a game-changer! I certainly don't know about the specifics of the energy involved, but if a good power supply could be used, such as nuclear, to provide the ion thrust needed to reach near-light-speed, and if it could be designed in such a way that the occasional mote of dust won't mean game over, then it should be attempted. I'm sure there's a way.
A few comments. E= 0.5 M * V * V So a one kilogram probe travelling at 10% of the speed of light would need 0.5 *1 * (2.998*10^7) * (2.998*10^7) = 4.494 *10^14 Joules. A large power station will produce 1 Gigawatt = 10^9W. So let us use that power station to get this probe to the required speed. Divide one number by the other gives us 4.494 *10^5 seconds or about 124 hours or about 5 days. In actual fact the probe would weigh tonnes, not kilos and you will have to add in the energy of the ions. In short, either my calculations are wrong or we will never send anything to another star. Also they used the HARPS component on the European Southern Observatorys 3.6-meter telescope, located at the La Silla Observatory in Chile, to capture the image. This is a bigger telescope than Hubble (2.4 meters), so Hubble is not relevant.
Hubble (in comparison to the New Horizons data that's recently started coming in) was an illustration of how limited telescopes are. I fear that telescopes can simply never replace an up-close visit, and so we should devise some way of getting to neighboring star systems. Going by what you've posted here, clearly such a craft will absolutely have to be kept light if it is to reach the needed velocities.
Technically you're off just a bit using Newtonian energy instead of relativistic. No big deal at 10% the speed of light, it's like a 1% error but as you get closer to the speed of light though the error will increase and the energy problem is even worse.
My main point is that it takes a lot of energy to go anywhere near light speed. Far more than what I had thought until I did these calculations. I very much doubt that until Warp drive or something similar is invented we will never send any object to another star.
Actually it's only money that gets in the way of seeing farther with more resolution. There are several concepts which might be 1000-2000 times better than Hubble. But money is the hurdle and NASA can't do much when it's total annual budget is something like $18 billion. Maybe one or more of our billionaire science enthusiasts working with private space exploration will help fund something? It's too bad all nations of the world don't get along well enough to joint-fund more space exploration...
Interesting from today's news; http://news.discovery.com/tech/alte...a-moving-toward-a-hyperspace-drive-150502.htm
Maybe these are crazy comments, but if we had the technology to travel at even .05% the SOL, or about 334,800 mph, how would we compensate for the acceleration and gravitational effects on the humans? We would also need forward-looking 'radar' that can detect objects 2790 miles out giving only 30 seconds of time to maneuver to avoid objects. And, what if at these speeds it's not possible to maneuver...how do you stop something moving 334,800 basically on a dime without the occupants going through the windshield? I think the answers might be like comparing I405 in LA with the speed lane of the Autobahn...if it is known there is nothing in our path then we can go any speed as long as the humans don't puke. But if there are obstacles then there is no choice but to greatly reduce speeds to necessary reaction times...
Remember to double all energy calcs, as the spacecraft has to decelerate at the other end. It does little good to reach another star if you just whiz by it at 0.1C.
But what about a very small, light craft? Seems to me something could be built. The instruments on New Horizons are very light, for instance, and a similar set could be installed on a very light, compact craft with energy sources that include solar and maybe something else, though it would seem that using solar to get up to speed and then going dormant until it gets near enough to the next star to begin collecting energy from it and using that to decelerate would be feasible. At least it wouldn't have to contend with possible shading, unlike the ESA's Philae lander that ended up dormant in a shadow on the surface of the comet being orbited and photographed by Rosetta right now.
That would be great, but you still need to 1. Be able to use sensors when the probe gets there. This takes mass 2. Send the findings back to earth. This would take a lot of energy and mass to do so. 3. Repair itself when damaged. 4. Prevent damage from dust on the way there. In short the probe will not weigh just kilograms, more like tonnes.
What about special shielding to prevent damage on the way? Like a hard but light protective cone on the front-facing side? This would hopefully also avoid a need to self-repair. We might also send two or three of them out at once rather than just one in order to increase our chances of success. That leaves the signal to sort out. I have no idea what kind of power we'd be looking at there or how the problem might be addressed. The only thought I can offer is maybe having a relay station between the destination and our system to capture, boost and rebroadcast the probe's signal. We might even try that with two, one near our system and one nearer the destination. Naturally this would be a risky, spendy venture, but I should think putting a sliver of the military budget toward the problem could work wonders.
One school of thought is that interstellar travel will be limited by the need for ablation shielding on the front of the spacecraft. When a spacecraft gets up to a significant fraction of lightspeed, the interstellar hydrogen it hits will start wearing away at the front of the spacecraft, no matter how hard the material is. Arthur C. Clark addressed this in _Songs of Distant Earth_, where the plot revolves around a large spacecraft making a stop mid-journey at an ocean planet, to augment their ablation shielding with large masses of frozen seawater. A different school of thought is that ramscoop ships will be built, which use magnetic fields to gather the instellar hydrogen and feed that into a fusion reactor, powering the vessel.
Shielding? It would have to be far better than bullet proof vests. That would take up a lot of mass. Remember there is a huge amount of energy released when even a small grain hits the probe. You work out the numbers.
