SKYLIGHTS

Astronomy news for the week starting Friday, January 1, 1999.

Welcome to 1999 with wishes for a good year and clear skies as we count down to the turn of the calendar and the year 2000. We appropriately begin our year with the Moon at its brightest, in full phase among the bright and lovely stars of Gemini. Since the Sun has just passed the winter solstice, the Moon will be just past the summer solstice, and will be the highest full Moon until next December 22, which will take place on the solstice day itself. Our companion then begins to wane through its gibbous phases, descending southward through Cancer, Leo, and then Virgo. The combination of the full Moon appearing on the first and a 31 day month gives us a somewhat unusual two full Moons in January.

As the full Moon announces the new year, so does Venus, which can now be seen low in the southwest in the glow of twilight, the second planet from the Sun to be brilliantly with us for the next several months. Not to be outdone, the Earth also goes through a special place this week. On Sunday, January 3, Earth passes orbital perihelion, where at a distance of 147 million kilometers (91.4 million miles) it is closest to the Sun. That perihelion occurs in the dead of northern winter clearly shows that the distance between the Earth and Sun is not the source of the seasons, which are caused exclusively by the tilt of our rotational axis.

Early January produces one of the better meteor shows of the year through the "Quadrantid" shower, which peaks the morning of Monday, January 4th and can produce up to a meteor per minute. Were the shower in summer it would be a popular as the August Perseids. Unfortunately, the bright Moon will somewhat get in the way. Meteor showers are usually named after the constellation from which the meteors appear to radiate. The Quadrantids are a faint reminder of the now-defunct, no longer recognized constellation Quadrans, the Quadrant, which was constructed in the 1700s from some faint stars near the Big Dipper. Two similar navigational devices, Sextans, the Sextant (south of Leo) and Octans, the Octant (which surrounds the south celestial pole), inhabit the sky, and presumably that was enough.