This is the 22nd anniversary of Voyager 1 's closest approach to the kingly planet, Jupiter. Just the day before, Voyager had sent back pictures that confirmed a suspected ring around this gaseous planet. Nevertheless, a comet as it nears the sun is pumping out tons of water and debris every second, making the vicinity of a comet a dangerous place for a spacecraft to be. When the moon rises after sunset, it will be framed against the backdrop of the constellation, Virgo . It ought to look pretty large, as well, since the moon was at perigee yesterday, its point of closest approach to the Earth.
Some conjunctions are just too tough to try.
Mercury and Uranus will lead the sun by a bare hour this morning and will barely be 15 degrees above the east-southeast horizon by sunrise. Planet watchers in the southern hemisphere will have an easier look at this dawn conjunction. This is the 24th anniversary of the discovery of the rings of Uranus by astronomers using the airborn jet, Kuiper Airborne Observatory . Uranus' rings showed up as a series of dips in the light of a background star before and after Uranus occulted the star. Using the jet allowed infrared astronomers to get above the worst and wettest layers of Earth's atmosphere without the expense of a space mission.