Dont forget to get a
visa you damn immigrants!
Paris - perhaps she'd let anyone in.
NASA's Kepler space telescope has sent home the first images of the starry patch of sky where it will soon begin the hunt for Earth-like planets. The first snaps show Kepler's entire field of view, a 100-square-degree portion of the sky in the Cygnus-Lyra region of the Milky Way, roughly equivalent to the size of two side-by- …
Errrrm - that is virtually in our own back-yard, astronomically speaking (only 889 410 655 650 164 600 brontosauruses away).
13 000 000 000 light-years away would have been mind-bogglingly far, though, being virtually on the edge of the visible universe.
El Reg, I think we need an astronomical unit as well - even "sheep_in_a_vacuum years" is too small a unit, one light-year being 587 877 328.312 sheep_in_a_vacuum years.
Mine's the one with the calculator in the pocket, thanks.
What a joke! It would take us 90'000 years to travel 3 light years with present state of our technology, and they are spending money convincing the public that we can make a "new home" 13'000 light years away.
I find it quite sad - this "let's convince ourselves that we can find somewhere else to live, then we don't have to worry about destroying this place." However, the sun will supernova at some stage in the next "x" billion years (....in other words, we don't know when) so I suppose there's nothing like thinking ahead. :-/
Humankind's planet finding ability seems to be improving (although I think some Oxbridge scientists have done work with ground level linked telescopes on this)
But have all the suns *Close* to Earth been checked? I mean no more than 10 light years. IIR there are not that many but I think they are the only ones we have a chance of reaching in a reasonable time (that's presuming we can get a probe to 10% of light speed, which is pretty ambitious) that someone on Earth would have a chance of being alive (and interested, hence willing to fund) such a project .
I look at these photo and the immensity, thw wonder and the beauty of reality take my breath away. And we, merely smart monkeys, are clever enough to find ways to peer into this deep space and seek evidence for something as small as our own planet. What religion, what set of stories, can ever achieve the sublime grandeur of what is?
Yes the local stars have all been tried - with existing technology. Radial Doppler can only detect tight-orbit Jupiters, and nulling interferometers (e.g. the Large Binocular Telescope) and dedicated planet-finding coronographs are in their infancy. So watch this space...
Kepler - and Corot - can find Terrestrials, but by occultation, so you need the planet's orbit to be just-so aligned with the line of sight, and exquisite photometry - hence the need for a wide-field camera in space. The optical arrays that you mention are made of ~1-m telescopes and don't have the sensitivity to detect planets - they're mainly used to study the atmospheres of red giant stars.
But on the motivation side... nobody's doing this to find a home for us when the Sun dies. The fraction of stars with planetary systems is a fascinating science question in its own merit. Cue arguments about the decline and fall of Rome, etc...
Your hand is a couple of feet away from you face, so you see it as it was a couple of nanoseconds ago. How do you know it still exists?
Sorry that's a bit trite - but we can only ever see our past light-cone. In astronomy, you see things as they were and you work in that time frame. They may be different "now", with a God's eye view of the universe that sees everything simultaneously, but you work with their evolution as it is seen under the well-supported assumption that the laws of physics are invariant in time and space.
FWIW, 13,000 years is a small timescale compared with stellar evolution, so they probably actually still do look the same today. Maybe if there was a very, very massive star in there it might have gone POP since and be sending its detritus towards us....
The Sun won't supernova... it'll go red giant in about 5 billion years and will shortly thereafter shrink to a white dwarf. It won't go bang unless someone then sneaks up about another solar mass of material and dumps it in an outrageously explosive act of cosmic fly-tipping...
I imagine you mean "100 square degrees", no?
@elfed dowler-jones: I don't think the point is to move out there, just find out (somehow) whether it's the sort of place that could support "life", whatever that might constitute outside the demesne of Mother Earth.
When we find such a planet we'll use Spock's device to ascertain the number and type of life-forms on it.
Then we'll know that we are not alone: we share this wilderness of barren rock, fire and space with some slime-like substance 13,000 light years away.
Thanks for that. I suspected they had been checked but its always worth a re-visit when technology improves, as it seems it has. With the caveat that if a planet does not occult the star we won't see it at all. So what are the odds that the plane of the ecliptic of other stars does not match our own?
While the process firms up the idea of how many stars of any given class have planets, "Earthlike" or not none of them are realistic options for a visit.
Yes, the idea of actually sending a probe to any of the nearby stars is far fetched at present but knowing that there was something else there other than just the sun might act as a spur in the same way the discovery of the Mars meteorite acted to raise interest in missions to Mars. However to have some chance of getting enough support to fund a mission the data returned would have to be returned in a reasonable time scale. I thought 30-40 years ( a working lifetime) would be viable (voyager was launched in the early 70s after all) with a century at the *very* edge of possible, where someone's children would be around to see the results. This needs a speed of at least 0.1C to deliver the results. This seemed to be both quite ambitious (given current exhaust velocities in the 10-40 kms range) but well inside of what is physically possible (if we only knew how).
Well, the chance of detecting the Earth by occultation against the Sun from a random line-of-sight is about 0.5%. (You'd be looking for a 0.001% dip in brightness that lasted a few hours once a year). So, given that there are only 11 stars with 10 light years of the Sun, it's not a huge surprise that we haven't detected any Earth-like planets yet - they may well be there, but with their orbits too far from edge-on. But my understanding is it won't be more that a few years before we start getting detections or good upper limits from direct imaging/interferometry.
Interestingly just yesterday the HARPS team (radial velocity) announced they had found a 2 Earth-mass planet - but in a 3-day orbit. They've been studying that particular system for a long time a have been beating down the signal/noise ratio, but the technique still fundamentally needs the planet to be throwing the star around at a fair speed.
As is often lamented we *could* build an Orion-type 0.05c ship now... more realistic I think would be a Deadalus-type 0.1c ship, in ~100 years maybe. As you say, knowing there was a terrestrial planet at the target star would be a huge motivation (that was indeed the basis for the Daedalus mission profile to Barnard's Star if I remember correctly) but I wonder if even on 100-year time scales we'd be rich and motivated enough to do it...
I had not realised the odds of the orbit being favourable were so long. It was my impression most planetary orbits were in a plane around their suns and most of these planes were themselves more or less parallel to each other. It helps to put some actual bounds on the size of this problem
“more realistic I think would be a Deadalus-type 0.1c ship”
The BIS are re-visiting the design to see what changes have occurred in 30 years. The substantial improvements in sensor technology should shrink the required payload quite a lot and the improvements in fusion understanding should increase efficiency. However mining Jupiter for the fuel will remain a big problem. Sadly the evidence for a suspected planetary system around Barnards Star seems to have been discredited
Outside Orion and Daedelus the only other idea would be the Starwisp idea of Robert Forward. Improvements in sensor processing have made the concept of a lens less large area sensor more viable. It also keeps most of the key bits in Earth orbit.
Sorry for being off line have been tied up in teaching!
Yes within in individual system, the planets ought to be reasonable
coplanar, if they've formed out of an accretion disc as we expect (and
conservation of momentum is a strong prior!). But that only means
within a few degrees, once they've had a bit of post-formation
battering - I think back-of-an-envelope for example, if Kepler found
Earth, it would have a about a 50/50 chance of getting one transit of
Mars; Mercury and Venus would be out through inclination, Jupiter and
further would be out through mission length.
But between stars - the ecliptics will be pretty much at random. So
Kepler would still need 200 solar systems to detect one Earth.
I hadn't head about the Daedalus revisit - will keep my eyes open for
that, it's still the horse I'd put my money on. Starwisp though -
unsteerable mirror that has to be also a Fresnel lens from Earth?
Free-flying optical arrays in ~AU orbit would have much greater senstivity
& mapping power - local angular resolution at a wavelength where the
targets are dim and with an unsteerable antenna isn't FTW! Seriously - blackbody in the Rayleigh-Jeans regime goes as nu^2. Push me offline and I'll calculate precisely how close you'd need to be to Earth with an off-axis 30-m cm-wave antenna to detect it. There's several orders of magnitude on the back of my bus ticket in favor of going for a local optical/IR search!
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