SKYLIGHTS

Skylights featured on Astronomy Picture of the Day

Scout Report Selection Webivore Selection SpaceCareers Selection

Skylights featured three times on Earth Science Picture of the Day: 1 , 2 , 3 , 4 .

Sky in the Pond

Photo of the Week.. An upside-down sky appears in the mirroring still bowl of a country pond, the right-side-up view showing an equally still sunrise.


Astronomy news for the week starting Friday, June 4, 2004.


The week begins with the Moon just past its full phase and into its waning gibbous phase as it rises progressively later each night. On Wednesday the 9th it will pass third quarter and begin the waning crescent phase of its earthly orbit.

From the beginning of 2004, Venus has dominated the western evening sky, showing us in the northern hemisphere one the best apparitions it has to offer. In mid May it began its disappearing act as it prepared to swing between us and the Sun, and on the morning of Tuesday, June 8, it will do exactly that as it transits across the solar disk, an event that has not taken place since 1882! Transits of Venus can occur only when "inferior conjunction" occurs at the same time that the planet, on its tilted orbit, is close to crossing the ecliptic. They occur in pairs eight years apart within a day or so of June 7 and December 8 each at intervals of 243 years with the those of the other date taking place in between. The last transit took place in December of 1882, the last June transit in 1769. The next one will be on June 6, 2012, the next pair in December of 2117 and 2125.

North Americans are at a disadvantage. East of a line that stretches roughly from central Texas to Montana, the transit will be underway at sunrise; west of the line, the Sun rises after the transit is over with. "Third contact," when the moving, leading edge of the planetary disk hits the edge of the Sun, takes place close to 7:05 AM EDT, 6:05 AM CDT, while "fourth contact" (when Venus takes leave of the Sun) takes place around 7:25 and 6:25 (EDT and CDT respectively).

Venus will appear as a black dot only a minute of arc across set against the brilliant Sun, and will be extremely difficult to see with the PROTECTED naked eye. The Sun is far too bright to look at directly, and professional eye protection (a proper filter) is MANDATORY. Do NOT use homemade devices/filters. The proper way to observe the event is the same as for an eclipse, to use projection through a telescope or even binoculars. Simply project the image onto a flat piece of paper, without in any way looking through the instrument.

The rest seems almost an anticlimax. Slipping away, Saturn sets near the end of twilight, while Mars follows almost an hour later. That leaves Jupiter to dominate the nightly sky, the giant planet (still south of the classical figure of Leo) setting around 1 AM Daylight Time.

Moving now to the east, Jupiter will formally enter the constellation Virgo in late August as it plunges ever farther south. Well to the southeast of the planet, locate Virgo's luminary, Spica, one of the hottest of stars of first magnitude.
Valid HTML 4.0!