Quote from: scienceguy on 08/25/2016 04:49 pmWouldn't the James Webb Space Telescope be able to get a picture of this planet? The star is just a red dwarf.Not even close. Proxima b has a separation from it's star of about 20 milli-arcseconds. The band limited Lyot coronagraphs in JWST's instruments have inner working angles varying from 400 mas to 800 mas. So the coronagraphs would not be able to spatially resolve the planet or even come close to it.In addition to that, there is the contrast problem. A terrestrial planet in the habitable zone of a mid M dwarf has a contrast of about 1 X 10^-8 dimmer than its host star. The coronagraphs on JWST are designed for about 1 X 10^-5 contract, since they are simple coronagrpahs without any wavefront control or diffraction suppression.WFIRST would get closer but the inner working angle of the coronagraph would still be too large for this planet.The best bet to study it in detail in the next few years would be if the planet transits its host star, which would allow JWST to use Transmission or Emission Spectroscopy on it.
Wouldn't the James Webb Space Telescope be able to get a picture of this planet? The star is just a red dwarf.
The planet is at the right place to have a temperature that allows the presence of liquid water on its surface. The question of habitability is however very complex. We need to confirm that this is a terrestrial planet. The best way to do that would be to directly image the planet using the giant telescopes equipped with extreme adaptive optics that are currently being built (i.e., the E-ELT, TMT, GMT). The angular separation between the star and the planet is 39 milli-arcsec, so a telescope as large as 30 m could resolve the system with the right instrument, detecting the planet and possibly giving us insights into its composition.
A guy on planetary.org said upcoming 30m+ telescopes should be able to directly image the planet....http://www.planetary.org/blogs/guest-blogs/2016/0824-proxima-centauri-b-have-we.html
I read a paper that stated the solar focus is not sueful for sharp images.no reason you cannot build bigger local imaging devices as you develop the infrastructor for making massive quantities of deuterium and antimatter
How about Fission Fragment propulsion? http://www.osti.gov/scitech/servlets/purl/6868318/This apparently old paper (attached below) about the early FFRE concept with fibers in fissionable material makes the case that a 10GW FFRE would deliver a 1 ton payload to Alpha Centauri in a century. Now we just need to find a way to build a 10GW FFRE. And find a way to radiate 10GW worth of energy from the spacecraft during its 40 years under thrust.The paper does make the case that this version of an FFRE is well suited to radiating the heat away from the fibers directly. Would that also apply to the dusty plasma FFRE that's been proposed more recently?
Quote from: wdobner on 08/28/2016 01:00 amHow about Fission Fragment propulsion? http://www.osti.gov/scitech/servlets/purl/6868318/This apparently old paper (attached below) about the early FFRE concept with fibers in fissionable material makes the case that a 10GW FFRE would deliver a 1 ton payload to Alpha Centauri in a century. Now we just need to find a way to build a 10GW FFRE. And find a way to radiate 10GW worth of energy from the spacecraft during its 40 years under thrust.The paper does make the case that this version of an FFRE is well suited to radiating the heat away from the fibers directly. Would that also apply to the dusty plasma FFRE that's been proposed more recently?Fine for a Daedalus fast flyby, but we might want a fast (in interstellar terms) journey time and an encounter which is as slow as possible.
I think a FOCAL telescope at 550 AU is the way to go.https://en.wikipedia.org/wiki/FOCAL_(spacecraft)
has there been any testing of a magsail? certainly not in space.
The problem, of course, is not just going there but coming to rest.
People realize that any orbital telescope for the solar focus is orbiting the solar system barycenter and not the center of the Sun. How much fuel would be needed to keep it at a point at that focus?
Some thoughts:1) No nation or private group is ever going to commit to a "starship" or probe until more is known about its destination.
2) As someone said, a space probe won't work. Unless we can create true artificial intelligence for it to operate itself
it would be increasingly impossible to control,
activate (you're not going to let it run its power and fuel out over years)
or even receive the data it finds because the distance needed to send and receive signals aren't going faster than light (and let's leave the SF out of it until someone invents something truly FTL).
Why does the probe need to receive commands? Just program it to send the right information. It doesn't need "AI" except in the trivial sense that is already used today on Mars.
Quote from: rdheld on 08/29/2016 10:55 pmPeople realize that any orbital telescope for the solar focus is orbiting the solar system barycenter and not the center of the Sun. How much fuel would be needed to keep it at a point at that focus?It's worse than that. The telescope is, in essence, the "secondary mirror" of the whole system, the primary lens is the sun's gravity which can't be steered. So if you want to track a moving target (such as an orbiting planet), then - to skew the view - you need to physically move the telescope laterally to the direction of travel. Similarly to moving the suspended receiver on a fixed dish like Arecibo in order to track targets.
Quote from: Paul451 on 08/30/2016 04:22 amQuote from: rdheld on 08/29/2016 10:55 pmPeople realize that any orbital telescope for the solar focus is orbiting the solar system barycenter and not the center of the Sun. How much fuel would be needed to keep it at a point at that focus?It's worse than that. The telescope is, in essence, the "secondary mirror" of the whole system, the primary lens is the sun's gravity which can't be steered. So if you want to track a moving target (such as an orbiting planet), then - to skew the view - you need to physically move the telescope laterally to the direction of travel. Similarly to moving the suspended receiver on a fixed dish like Arecibo in order to track targets.Depends on the field of view of the telescope.
Quote from: MattMason on 08/30/2016 12:39 amSome thoughts:1) No nation or private group is ever going to commit to a "starship" or probe until more is known about its destination.This statement is trivially true. There is serious scientific hay to be made by JWST and the 39m E-ELT, instruments already under construction, let alone ones that will be built in the future.Quote2) As someone said, a space probe won't work. Unless we can create true artificial intelligence for it to operate itselfLike what? think of a probe as just a sensor. It just needs to receive information and broadcast it. Quoteit would be increasingly impossible to control,You pre-program it with instructions, obviously.Quote activate (you're not going to let it run its power and fuel out over years)And why not? Voyager 1 and 2 look like they'll probably last for half a century, which is longer than Breakthrough Starshot will need (for instance). Quoteor even receive the data it finds because the distance needed to send and receive signals aren't going faster than light (and let's leave the SF out of it until someone invents something truly FTL).Why does the probe need to receive commands? Just program it to send the right information. It doesn't need "AI" except in the trivial sense that is already used today on Mars.