In the New York Times, Dennis Overbye talks about how a new approach to astronomy is allowing scientists to better observe what's out there, in their quest to continue looking for planets, solar systems, and maybe other forms of life.
Since 1995, around 250 planets outside the solar system, or exoplanets, have been discovered. But few of them are in systems that even faintly resemble our own. In many cases, giant Jupiter-like planets are whizzing around in orbits smaller than that of Mercury. But are these typical of the universe?
Almost all of those planets were discovered by the so-called wobble method, in which astronomers measure the gravitational tug of planets on their parent star as they whir around it. This technique is most sensitive to massive planets close to their stars.
The new discovery was made by a different technique that favors planets more distant from their star. It is based on a trick of Einsteinian gravity called microlensing. If, in the ceaseless shifting of the stars, two of them should become almost perfectly aligned with Earth, the gravity of the nearer star can bend and magnify the light from the more distant one, causing it to get much brighter for a few days.
If the alignment is perfect, any big planets attending the nearer star will get into the act, adding their own little boosts to the more distant starlight.
That is exactly what started happening on March 28, 2006, when a star 5,000 light-years away in the constellation Scorpius began to pass in front of one 21,000 light-years more distant, causing it to flash. That was picked up by the Optical Gravitational Lensing Experiment, or Ogle, a worldwide collaboration of observers who keep watch for such events.
Now, back to my thesis. Enjoy the weekend everyone.