New Space Telescope will Search for Earth-like Planets

[Puppycow]

Spacecraft Seeks Earth-Like Planets

A new spacecraft, built to hunt the heavens for other Earth-like planets, roared into space from the Kennedy Space Center on top of a Delta 2 rocket at 10:49 p.m. Friday.

The craft, Kepler, named after the German astronomer Johannes Kepler, who discovered the planetary laws of motion, is to spend the next three and a half years in an orbit around the Sun, where it will count planets by looking for the tiny blips in starlight caused by planets eclipsing their suns.

NASA scientists said they would spend the next two months checking out the spacecraft. During the $600 million mission, Kepler will stare at a patch of the Milky Way in the constellations Cygnus and Lyra, recording the brightness of 100,000 different stars every half-hour. It is equipped with the largest digital camera ever flown in space.

The goal is to accomplish the first rigorous census of planets and determine how rare or common Earth-like planets really are. Astronomers associated with Kepler estimate that they could find dozens of such planets in so-called habitable zones suitable for life as we know it, but that it would take about four years to establish their presence. The answer should pave the way for future efforts to study and collect images of terrestrial planets and to search for signs of life.

I think this is very exiting. This is exactly the sort of space mission I would be directing more resources too if I was to choose what we spend our space exploration money on. That is, powerful space-based telescopes.

As powerful as the telescope is, the distances involved are so mind-bogglingly huge that we can't actually "see" the planets themselves, we can only notice a very slight darkening of a star when a planet passes in front of it.

But I hope that they will one day invent a telescope so powerful that it can actually see planets in other solar systems. That would be truly awesome.

 

[six7s]

Voisins Avec Nez Grande Sans Le Frontières Finale?

 

[Travis]

I'm hoping we'll get some space based interferometers one of these days. Then we might be able to image these planets directly.

 

[bjornart]

But I hope that they will one day invent a telescope so powerful that it can actually see planets in other solar systems. That would be truly awesome.

You mean like this: Fomalhaut b?



Yeah, I know, you were probably thinking of more than just four orange pixels.

 

[Dragoonster]

Very cool.

But as an ignoramus on such things, I have to assume the astronomers are sure that the "brightness blips" mean planets and only planets. How certain is this?

 

[MG1962]

Very cool.

But as an ignoramus on such things, I have to assume the astronomers are sure that the "brightness blips" mean planets and only planets. How certain is this?

Think of it this way. You are in the woods, and you know a bear is hiding behind a tree, but not which one. Suddenly the bear growls. Now you still cant actually see the bear, but you know what tree it is behind. You will start watching that tree more intently for further evidence

On the reverse side. Astronomers usually only write papers on confirmed findings. Many have lists of stars they think might have a planet, but their own facilities can not confirm an answer either way. They dial up this telescope, get it to look the particular star and report back.

One thing this new scope should do is reveal patterns. Do certain types of stars always seem to have/not have planets. Are certain parts of the sky better suited for planetary creation or not. Example we find none towards the core of our galaxy, but there is a housing boom in the outer spirals

 

[Puppycow]

Very cool.

But as an ignoramus on such things, I have to assume the astronomers are sure that the "brightness blips" mean planets and only planets. How certain is this?

This more detailed article explains

Many technical hurdles had be overcome before Kepler became practical. In particular it required very accurate and sensitive digital detectors, said James Fanson, of the Jet Propulsion Laboratory, Kepler’s project manager. As seen from outside the solar system, the Earth blocks only about 0.008 percent of the Sun’s light when it passes in front, or “transits.” Kepler has been built to detect changes in brightness as small as 0.002 percent, equivalent to a flea crawling across a car headlight.

By measuring the diminution of a star’s light during an exoplanet transit, astronomers in principle will be able to determine the size of the exoplanet. From the intervals between eclipses, astronomers will be able to determine its orbit.. By combining this with other data, from, say, wobble measurements, they will be able to zero in on important properties like mass and density.

However, natural variations in the star’s output, caused by something like starspots, could interfere with the data and obscure the signals from small planets. That is a problem, Dr. Fanson said, with the Corot satellite, which was launched by the European Space Agency at the end of 2006 and also carries a telescope and camera to look for small changes in starlight. To weed out the noisy stars, Kepler will keep track of 170,000 stars for the first year and then narrow its attention to a mere 100,000.

So it won't be easy, but you gotta hope that with 100,000 stars that you will find some regular patterns. Say, a 0.008 percent darkening that occurs every 357 days is probably not a sunspot. So they'll have to look for those patterns.