Villanova University astronomer Edward Guinan has had some adventures over the years, from scrounging for black-market cement to make Iran's first high-powered telescope to discovering the rings around Neptune at an observatory in New Zealand.
But none of this will compare, he said, to witnessing the discovery of the first Earth-like planet orbiting another star - a feat that a NASA satellite called Kepler could do within the coming weeks.
In the early 1990s, Guinan wrote a paper suggesting the planet-hunting method that Kepler is employing - looking for tiny eclipses as planets pass in front of their stars. Such eclipses, called transits, can show up as dips in a star's brightness.
More recently, he urged NASA to shift the focus of the project to include a number of stars much dimmer than our sun - red dwarfs. That's where he is betting the first Earths will be found.
"I never thought I'd live to see this," said Guinan, 67, who is optimistic about the project's success.
The space-based Kepler telescope was launched in March and has begun monitoring about 100,000 stars in a region about twice the size of the Big Dipper's scoop.
While Kepler was designed to concentrate on bright stars like the sun, it will now also look at 4,000 red dwarfs, said Jon Jenkins, a principal investigator on the project. It also will look at 40,000 so-called K stars, which Guinan calls orange dwarfs. They are brighter than red dwarfs but dimmer than our sun.
They are also great prospects for habitable planets, said Guinan.
These lesser stars are being included thanks to the influence of Guinan and Andrej Prsa, a Villanova post-doctoral researcher who developed an artificial intelligence system that is helping Kepler distinguish real planets from false alarms.
Planets are more than a billion times dimmer than the stars they orbit, which is why it's so hard to see them.
Even indirect methods are tricky. A transit of another Earth would dim a star such as the sun by less than a hundredth of one percent.
This is one reason Guinan is excited about red dwarfs, also called M dwarfs. They hold less than half the sun's mass and give off less than a tenth of its energy.
If an Earth-size planet passes in front of a red dwarf, it will cause a relatively big dip in the star's brightness compared with what Kepler would see if the same planet transited a bright star like the sun.
Another reason red dwarfs are so interesting is that they make up about 80 percent of the stars in the galaxy.
In the last two years, astronomers have begun to find some of the most Earth-like planets yet around red dwarfs - not quite Earths, but a class called "super Earths." Ranging from two to about 20 times the size of our planet, super Earths may be covered in ice, rock, or even oceans.
But could planets around such low-wattage stars sustain life? Guinan's calculations show it's possible.
For the last seven years, he's been exploring the life question, along with his colleague Scott Engle, as part of a program titled "Living With a Red Dwarf." This project encompasses not just theoretical work but a comprehensive study of red dwarfs using an automated "Four University" telescope in Arizona, as well as data from the Hubble Space Telescope and several NASA and European satellites that observe the sky in ultraviolet light and X-rays.
Guinan works with undergraduates as well as Engle, a Villanova graduate now officially with James Cook University in Australia.
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