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Kepler Confirms Exoplanet Inside Star's Habitable Zone
astroengine writes "Plenty of 'candidate' exoplanets exist, but for the first time, Kepler has confirmed the existence of an exoplanet orbiting its Sun-like star right in the middle of its 'habitable zone.' Kepler-22b is 2.4 times the radius of Earth and orbits its star every 290 days. 'This is a major milestone on the road to finding Earth's twin,' said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington. 'Kepler's results continue to demonstrate the importance of NASA's science missions, which aim to answer some of the biggest questions about our place in the universe.'"
I've looked a bit this morning and can't find anymore info about the star itself. What its apparent magnitude it? What constellation its in? Etc. All I can figure out is its referred to as Kepler 22 which only makes sense in relation to the program. But I'd love to be able to try and see the star through a telescope.
Many of you may already be aware of this, but it is likely that going forward we will find these "goldilocks" planets with more regularity. Kepler luanched in 2009 with first observations in Jan 2010 and discovers planets using the transit method. Basically, a planet blocks part of its home star's light, and sensitive instruments can pick up on this difference in light. Two transits create a pattern to follow up on, the third transit is considered confirmation of the existence of a plant. So almost 3 earth years of observations means finally being able to detect planets with year long orbits (slight error in logic, depending on when you catch the planet in the act...)
So we are getting to the point where the data should start pouring in on planets more similar to our own. In another 12 months, I would expect to see hundreds if not thousands of planets similar to our own. That is when I think things get interesting. Say we find only 100 "habitable" planets... follow-up observations should give us an idea about the existence or nonexistence of life. Is it common? Is it uncommon? Are we just one of millions of life bearing planets? Are we an outlier? The mind boggles at what we will learn.
This is an interesting time to be alive :)
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Kepler can only see planets with orbits edge-on to us, and it's only looking in one specific direction. For each planet it finds, we can expect there are 50,000 more that are closer. On average, the closest will be 30-40 times closer than the one it finds, thus 15-20 light years in the case of Kepler-22b. Still a long way away, but easier to get to.
And no, the next best plan is not to explore it with robots, it's to use the Sun itself as a gravitational lens in a mucking huge telescope. To use it for that, you need to get to the focus distance of the Sun, which is more than 550 AU out. As a practical matter, you likely need to be more like 1000 AU out, since at the minimum distance you are focusing light that just barely grazes the Sun's surface, and the light from the Sun itself is hard to block out in that case. Farther away you can use an occulting disk to block the Sun + some margin around it.
Because of the huge diameter of the Sun as a lens, you can get absurd levels of detail at a nearby star, on the order of 0.4 meters per light year of distance.