Recent progress in bioastronomy space missions

The light-bending effect predicted by general relativity is by far larger around the Sun (because of its large mass) than around any other body in the solar system. The Schwarzschild solution to the Einstein equations yields its value: 4GM/(r c(2)), r denoting the "impact parameter" i.e., the minimal distance between the center of the Sun and the bent light path. If the light rays come from very far away, practically from an infinitely distant source, it can then be proved that the radio waves grazing the surface of the Sun are focussed by its mass into a point on the other side, called the "nearest focus" of the Sun's gravity lens, whose distance from the Sun is about 550AU, or 3.17 light days, or 14 times the Sun-Pluto distance. However, every point beyond 550AU a's a focus also because these points are hit by rays having a higher impact parameter and so less deflected. A spacecraft with a good radio antenna moving outward from the solar system along the focal axis (the straight line from the source through the center of the Sun) to 550 AU and beyond will be able to take advantage of the huge radio magnifications provided by the Sun's focussing effect, namely it would achieve a terrific angular resolution of the source. Recently (1999) new experimental perspectives were opened by NASA's decision to set up an "Interstellar Probe Science and Technology Definition Team", of which the author of this paper is a member. NASA's Interstellar Probe (ISP) is expected to be launched in June 2010 and reach 250 AU in about 15 years. It will be "pushed" out of the solar system by a 400-m hexagonal solar sail and a suitable flyby of the Sun. ISP will explore the heliosphere, its termination shock (at similar to 120 AU), and the plasma physics there. ISP's exit direction from the solar system will be toward the heliopause's ''nose," namely -16 degrees in declination and 16.6 hours in right ascension tin Scorpio and Ophiucus). Then ISP will keep going straight along this direction forever and will eventually cross the Sun's focal sphere at 550 AU around the year 2043. We could take advantage of this circumstance to experimentally prove the existence of the Sun's focus by letting ISP carry a photometer/bolometer capable of detecting the huge influx of the cosmic background radiation (CBR) focussed upon ISP by the Sun. Apart from detecting the Sun's focus for the first time, this would be a valuable result for of cosmology, too, inasmuch as the angular resolution on the CBR provided by the Sun's lens turns out to be nine orders of magnitude better than that of NASA's Cosmic Background Explorer (COBE).