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Earth to...Earth? Are you there?
jasamaman writes "So far all the planets found outside our solar system have been gas giants. So they are not habitable, and couldn't really hold life as we know it. But "planet hunter" David Charbonneau is looking for another planet just like Earth, and claims that astronomers are "very close"."
How the hell could he know that we are "very close" to discovering anything?
Did miss cleo tell him?
I know I'm going to hell, I'm just trying to get good seats.
I see the pointy that any further information about space (even out of our solar system) is useful, but what would we do if we found an earth-like planet?
It is expensive and time consuming to send a probe to Mars, would we really want to investigate this far off planet before we properly explore our own solar system? And put the money in when the results may only come back years after we are all dead? Nope.
"None are more hopelessly enslaved than those who falsely believe they are free." -- Goethe
Until the launch of "Darwin" by the ESA, (pdf link) it is unlikely that we will be able to detect earth-like planets. We still cannot detect Jupiter sized worlds at this point in time.
Just you're average nitpicker.
The sun of our solar system contains more than 99,9% of its mass. Of the remaining 0,1%, most is of the megaplanets like Jupiter and Saturn. Jupiter alone has around 500 times the mass of Earth. Habitable plants are thus incredibly, incredibly small compared to their suns or compared to gas giants. Given the limited funding (forget space, we need missile defense!) we can be happy that we can detect gas giants.
well, we do need some place to evacuate to if the Vogons come to buildt an interstellar bypass and destroy the earth in the process.
Lets find 42 alternative planets earth
have recently determined that amino acids (protein building block molecules) are formed in a vacuum which would perhaps mean that most life would be formed on the same basis as we are, perhaps it would be easier to look for old radio transmissions and TV-signals as SETI does. Have the people at SETI ever done any modelling to see what our old TV-signals would look like 10 light years from earth?
,winds and life in general.
Another thing that might be vital to life on earth might simply be the fact that we have such a large moon acting as both a shield to a lot of asteroidal bombardment and as a planetary motor for tides
There are a number of ways Earth-sized planets could be discovered fairly soon (within the next 5-10 years). There are several planet-finding satellites to be launched. The Hubble would also be capable of detecting an Earth-sized planet passing in front of a star.
The real trick is finding the proper conditions. First, we need to find an extra-solar system in which Earth-sized planets exist. It's now believed that these are fairly few and far between. The reason is that a vast majority of the gas giant systems we've discovered so far have their gas giants in either really close orbits to their stars, or are highly eliptical with passes close to their stars. In these situations, Earth-like planets would likely be tossed into their stars, or more likely, tossed into open space, by the gravitational effect of the giants.
So, what you need is giants that live fairly far out (like Jupiter and Saturn). These appear to be about 1 out of 50+ systems. So, out of this 1-2% of systems, we then need to find ones with orbital planes that are parallel to our angle of view of those systems, and catch the Earth-sized planets passing in front of their stars.
Asking for all those conditions to line up is a pretty tall order, so it's unlikely we'll catch such an event in the next 5 years. My personal opinion. A large breakthrough may change that, and that's possible as well. After all, look at the discovery of extra-solar planets. It was a breakthrough idea that led to a sudden discovery of many of these systems, without a real technilogical breakthrough.
That's true. Astronomers are very close. However, where the hell all these planets are is quite another matter...
Cheers,
Ian
if you have any plausible suggestions, by all means, make them. But till then, the only way I can see to get life is carbon-based life forms. Yeah, I could be wrong, but I'm betting on other life forms also being carbon-based. Not proof, but strikes me as a good bet.
But the detection of those elusive, small Earth-like worlds may be closer than you think
I've seen lots of Science Fiction movies about aliens that go from planet to planet, soaking up the natural resources of each, conquering and destroying them (making them uninhabitable), and moving on. Anyone else ever think we're the aliens?
I mean, we've already screwed up this one, and now rather than fix it (because wanting to do that makes you a "tree hugger") we're going after another. I can't say I'm against it, but it's just...creepy.
Power-law distributions (more smaller stuff) suggest there should be lots of earth-size planets. However the current methods can only see fast-moving larger-than-Jupiter planets. The most popular method is measure faint doppler shifts over months to years. Terrestrial pectroscopic resolution limits this to about 10x Jupiters. Space-based methods may be more sensitive.
.0001% of time the planet is eclipsing,
and (c) you aren't seeing a variable star like
Algol. The US will soon launch a special telescope called Kuiper to watch one splotch of sky for five
years continuously to catch planetary eclipses.
Kuiper is notable for its 350 megapixel camera.
Another method is to look for eclipses of planets across the stars. This presumes (a) you are seeing another solar system edge-on, (b) you are lucky to catch the
A third method is infra-red, which can see earth-size in newly forming planetary system dust-clouds. These would be too young and unstable to have evolved intelligent life on their own, but could be colony sites.
I'm glad you posted the section you did here, as I didn't remember his exact words (and I can sometimes be a stickler for comparing what he said to what people think he said.) It says, "We are close to being able to find Earth-like planets." He doesn't say we're close to finding one, just that we're close to being able to find one. That's quite a big difference, especially when you consider that space is mostly empty. It could be 20 years after we are able to find one that we actually do.
Just to kind of explain that to some of our slower readers... and this is in no way accurate, but just an example to help understand... if putting a coke bottle on the end of a telescope enables us to detect Earth-like planets, then we still have to search the skies with that telescope. That could take a long time, with the vastness of space.
It's easy to stand out when the general level of competence is so low.
The closest thing that has been discovered is the two gas giants around 47 Ursa Majoris. This is the planetary system that so far looks most like our own. The two giants have less extreme (more circular) orbits than most of the ca 70 planets found, which also contributes to make it look a lot like ours. Gas giants can be an important contributor for life to appear on a smaller planet, since they act like magnets for asteroids and other debris, sheltering the smaller planets and giving life a chance to evolve.
Opinions stated are mine and do not reflect those of the Illuminati
Actually, he's referring to this older Slashdot article, which you must've not read.
Now whether this formed in a vacuum or not is a technicality. The scientists shone high level of UV light on a chunk of ice containing ammonia and methyl alchohol at a temperature of 4K and found traces of 3 amino acids had formed. The amino acids themselves formed from the surrounding ice slurry which was in a vacuum, ergo "amino acids are formed in a vacuum."
If it's for-profit but free, you're not the customer -- you're the product (e.g., the Slashdot Beta's "audience").
Parallax determines the presence of an undetectable massive companion by the sinusoidal proper motion of the star system over a course of a few years. On the ground, you can do this for only a dozen of the closest stars (10 parsecs) or so.
Doppler reflex motion detects the companion by the Doppler shift in spectral lines in the parent star's spectrum as the planet/star orbit about their mutual centre of gravity. You can do this out to 100 parsecs or so.
HD209458 was a candidate from the Butler and Marcy Doppler survey that had a high inclination (edge-on) orbit. Brown and Charbonneau then did photometry to get the transit of the planet across the star's disk. Parallax did not come into it.
Dr Fish
shh, this planet here is one of the most habitable in the universe, but also one of the most dangerous, with sharp venomous teeth. now we're just going to sneak up on it.... oh no, it's got life forms! crikey!