January 2017

Welcome to SkyEye, your guide to this month's celestial events.

The Calendar

Date Event
Sunday 1
Monday 2
Tuesday 3 Moon occults Neptune: visible from most of southeastern Asia, Micronesia, Hawaii, western coast of North America.
Moon occults Mars: visible from southern tip of India, most of southeastern Asia, Micronesia.
Dark skies welcome the Quadrantid meteor shower. Expected peak activity is around 14:00 UT.
Wednesday 4 Earth at perihelion
Thursday 5 First Quarter Moon
Friday 6
Saturday 7
Sunday 8
Monday 9 Moon occults Aldebaran: visible from northeastern Africa, Arabia, India, China, Japan.
Tuesday 10 Moon at perigee
Uranus at east quadrature
Wednesday 11
Thursday 12 Moon occults Regulus: visible from southern South America, parts of Antarctic.
Full Moon
Venus at greatest elongation east
Friday 13
Saturday 14
Sunday 15
Monday 16
Tuesday 17
Wednesday 18 Vesta at opposition
Thursday 19 Mercury at greatest elongation west
Last Quarter Moon
Friday 20
Saturday 21
Sunday 22 Moon at apogee
Monday 23
Tuesday 24
Wednesday 25
Thursday 26
Friday 27
Saturday 28 New Moon
Sunday 29
Monday 30 Moon occults Neptune: visible from most of central Africa, Saudi Arabia, India, western China.
Tuesday 31

The Solar System

The word planet is derived from the Greek word for 'wanderer'. Unlike the background stars, planets seem to move around the sky, keeping mostly to a narrow track called the ecliptic, the path of the Sun across the stars. Dwarf planets and small solar-system bodies, including comets, are not so constrained, often moving far above or below the ecliptic.

Sun SagittariusCapricornus

The Earth makes its annual closest approach to the Sun on 4 January. The date of perihelion can range from New Year's Day to 5 January.

Mercury Sagittarius

The closest planet to the Sun is found in the east at dawn. Easier to spot in the southern hemisphere than the north, Mercury reaches greatest elongation west on 19 January.

Venus AquariusPisces

The evening star still commands the western skies after sunset. It is best seen from northern latitudes where it continues to climb higher above the horizon. However, it appears to be getting lower in the sky when seen from the southern hemisphere. Venus reaches greatest elongation east on 12 January.

Mars AquariusPisces

Setting in mid-evening, the red planet is found very close in the sky to Neptune on the first day of the month. A small telescope should show both objects in the same field of view. On 3 January, both planets are occulted by the Moon.

Vesta Cancer

Sixth-magnitude Vesta is at opposition on 18 January and is an excellent object for binoculars.

Jupiter Virgo

Now rising around midnight, the largest planet in the solar system is well aloft by sunrise.

Saturn Ophiuchus

The ringed planet is a morning sky object and may be lost in the glare of the rising Sun.

Uranus Pisces

This ice giant is at east quadrature on the tenth day of the month and sets around midnight.

Neptune Aquarius

A small telescope is necessary to view the most distant planet in the solar system. However, with solar conjunction approaching in early March, it is getting increasingly difficult to observe. Found near Mars in the evening twilight sky at the beginning of the month, it and the red planet are occulted by the Moon on 3 January. Neptune is occulted a second time on the penultimate day of the month.

The Celestial Sphere

Constellations are patterns of stars in the sky. The International Astronomical Union recognises 88 different constellations. The brightest stars as seen from the Earth are easy to spot but do you know their proper names? With a set of binoculars you can look for fainter objects such as nebulae and galaxies and star clusters or some of the closest stars to the Sun.

Descriptions of the sky for observers in both the northern and southern hemispheres are available for the following times this month. Subtract one hour from your local time if summer (daylight savings) time is in effect.

Local Time Northern Hemisphere Southern Hemisphere
1730 hours (1830 hours summer time) 45° N 30° S
1930 hours (2030 hours summer time) 45° N 30° S
2130 hours (2230 hours summer time) 45° N 30° S
2330 hours (0030 hours summer time) 45° N 30° S
0130 hours (0230 hours summer time) 45° N 30° S
0330 hours (0430 hours summer time) 45° N 30° S
0530 hours (0630 hours summer time) 45° N 30° S