The Shallow Sky

Akkana Peck

Mercury is still in the morning sky, but by month's end it will be getting closer to the sun and therefore more difficult to spot. It will become an even more difficult target over the next few months.

Venus shines in the evening sky, setting later as the month progresses. It will present a small, bright, gibbous disk to the telescopic observer.

Mars will be visible in the nighttime sky all through 1999. In January, it rises a bit after midnight, and reaches quadrature on the 16th. Its disk grows to 7.9" by month's end; over the next few months it will grow rapidly as it nears its upcoming opposition.

Not much detail will be visible on its surface yet -- but it might be worth a look, especially on nights of good seeing.

Jupiter is still well up at sunset and is well placed for observing in the early evening. There's been a wealth of detail visible on Jupiter this year, especially around the region of the Great Spot Formerly Known as Red; it's a great view in any telescope.

There will be a double shadow transit, of Io and Ganymede, on January 14 from 9:30 until 11:30; and another, also Io and Ganymede, on the 22nd from 12:30am until 2:30 (while the two satellites involved make a close pass themselves, closest an hour or two after Ganymede's shadow leaves the planet's limb).

Can you see a difference in size or character between the shadows of these two moons? As always, you can get Jovian moon and shadow predictions from // iter.html.

Saturn is high in the sky at sunset and will be observable until around midnight. Quadrature occurs on January 17th; look for the shadow of the planet on the rings, since it will be most noticeable at quadrature.

Uranus, Neptune and Pluto are all very close to the sun and difficult to observe, though by the end of the month Pluto becomes a possible target in the morning sky.

Don't forget about the lunar occultation of Aldebaran, on January 26 from 11:35 to 12:37. Binoculars or a small rich-field telescope are ideal for watching Aldebaran occultations.

Akkana Peck; last updated: 1998 Dec 15 Prev Next