On Out There, Corey S. Powell describes one of those cosmological phenomenon that makes my jaw drop:
One of the most intriguing destinations out toward the Oort Cloud is not an object but a conceptual location, the “solar gravity lens” point. Bear with me for a second, because this one is weird but truly wondrous.
The gravitational field of the Sun subtly warps the space around it, following the rules of Einstein’s general theory of relativity. At a great distance from the Sun, the warped light rays come together, just like the focal point of a magnifying lens. If you are standing at that point and you look back at the Sun, you see a greatly magnified version of whatever is on the other side–again, just like a magnifying lens.
A new study funded by NASA Innovative Advanced Concepts (NIAC) demonstrates the astonishing sights available to a space telescope placed at the solar gravity lens point. So far, astronomers have observed only a handful of planets directly, and these are seen merely as unresolved dots; most are detected only indirectly. But using the Sun’s magnifying power, a properly sited space telescope could scan the surface of an Earthlike planet 100 light years away at a resolution of about 1 kilometer!
Wow! Here’s a diagram from the academic report from which Powell is working:
Figure 8. Imaging of an exo-Earth with solar gravitational lens. The exo-Earth occupies (1km×1km) area at the image plane. Using a 1m telescope as a single pixel .detector provides a 1000 × 1000 pixel image
Notice the telescope will be staring at, or near, the Sun. Fascinating stuff!
