Apollo 15 . ... 1971) --- Astronaut James B. Irwin, lunar module pilot, walks away from the Lunar Roving Vehicle (LRV) during the third Apollo 15 lunar surface extravehicular activity (EVA) at the Hadley-Apennine landing site. The LRV is parked a short distance from the rim of Hadley Rille. ... While astronauts Scott and Irwin descended in the Lunar Module (LM) to explore the moon, astronaut Alfred M. Worden, command module pilot, remained with the Command and Service Module (CSM) in lunar orbit. ...

... ARTICLE: The Adventurous Search For The Astronomical Unit . ... Kepler himself had suggested to use the rare occasions of Venus transiting (crossing) the solar disk to measure our distance to the planet. ... Due to the orbital inclination of Venus against the ecliptic of 3.5°, a Venus transit is so rare that it happens only at intervals of 121.5 years, 8 years, 105.5 years, 8 years and so on. ... Crabtree witnessing the transit of Venus 1639 . ... Transits of Venus - The Quest for the Solar Parallax...

Physical limit to variability timescale 1 1 2 The central engine can change its state in a time Rg /c Rg ­ Schwarzschild radius The faster blob catches up with the slower one at the distance Lin Lsh = c 2 2 Lin 1 v2 - v1 L in ~ R g 2 1 L sh The minimum apparent duration of the light burst (at = 0): Lsh Rg 2 2 c c Geometrical implications Instantaneous and synchronous (in the lab frame) release of energy by the sho ck results in ...