How did the first stars and galaxies bring the young universe out of its dark ages and into the light? Three prominent researchers, including Harvard Astronomy Professor Avi Loeb, discuss how new instruments and observational techniques may find the answer.
The cores of most galaxies are thought to harbor black holes with masses of a million or more suns. But many remain unseen until an unlucky star passes too close and is pulled apart by tidal forces. The stellar debris gathers into a disk and spirals towards the black hole in the center. As it does, it may form a jet of material that beams high-energy light like a flashlight. Last spring, the Swift satellite measured a flare of x rays and gamma rays from a distant galaxy that has the hallmarks of such a jet that happens to point right at us.... Read more about Synopsis: Tidal Disruption of a Star (N. Stone and A. Loeb)
Before Ed Turner and Avi Loeb tell you about their research, they want to make one thing perfectly clear: they do not claim there's a city on Pluto. But if there were, they say, we could see it. And, as they suggest in a paper they've submitted to the journal Astrobiology, it's worth taking a look, just in case.
By Karen Weintraub Cambridge, Massachusetts November 8, 2011
Hollywood is wrong about aliens. They don't have oddly shaped heads, bulging eyes or even an eery green hue. Dimitar Sasselov is pretty convinced of that.
He's not even sure we'll know them when we see them. Prof Sasselov, an astrophysicist, thinks that if life exists elsewhere - and he believes it does - it will likely be based on different building blocks than ours, and so may not even be recognizable as life.
A project he's heading at Harvard University, called the Origins of...