It is nearly time to bid farewell to an old friend. Voyager 1 was launched on Sept. 5, 1977 to study the outer planets and many of us thrilled to the pictures of Jupiter and Saturn it sent back in 1979 and 1980. Now Voyager 1 is close to leaving the solar system. Its Low-Energy Charged Particle Detector has been registering zero for months now meaning that the sun’s streams of ionized particles and plasma are not reaching it. The spaceship is 10.8 billion miles from the sun and it takes over 16 hours for a signal from it to reach Earth. “Voyager 1 is getting close to interstellar space,” says Ed Stone of the California Institute of Technology but it will take another four years to be entirely free of the solar system. It will sail alone through deep space for about 40,000 years before ending up near a star in the constellation Camelopardalis.
Focus on the planets
Jupiter dominates the evening sky in January while Venus takes the spotlight during the early morning hours.
Mercury shares the spotlight with Venus rising low in the southeast at dawn as the month opens. Note reddish Antares just to Mercury’s upper right.
Venus is unmistakable blazing high in the southeast well before dawn. As the new year opens Venus rises three hours before the sun and is visible well into the dawn.
Mars sets with the sun and will not be visible in January. Mars passes behind the sun in early February.
Jupiter is about halfway up on the southwest horizon at nightfall and stays in view until around 11 p.m. By the end of the month the giant planet will be setting by 9:30 p.m. Take advantage of the few hours of viewing time watching the dance of Jupiter’s four moons around and across the face of the planet.
Saturn rises shortly after midnight and is high in the south at dawn. The rings are tilted at 10 degrees from edge-on, the most open they have been in three years. Saturn’s major moon Titan is also readily visible with backyard telescopes.
Uranus is identifiable as a blue-green disc in the same binocular view as Jupiter. Not until 2038 will these two planets be in such close proximity.
Neptune is very low in the southwest early in January but is all but below the horizon when it is dark enough to locate its pale blue-gray disc. The best opportunity will come on Jan. 7 when it is just south of the crescent moon.
3 Earth at perihelion or closest approach to the sun. The Earth is aphelion or its most distant on July 4, but remember, it is tilt and not distance that determines our warmth.
4 New moon, 4:03 a.m. This is the peak night for the Quadrantid meteor shower and, coinciding with the new moon, viewing should be superb if not overcast. Look for 100-120 meteors per hour radiating from the northeast in the vicinity of Polaris.
10 Moon at apogee or farthest distance from Earth. Jupiter is high in the west around 9 p.m. with the crescent moon to the upper right.
12 Moon in first quarter, 6:32 a.m.
14 This is Jan. 1 on the old Julian calendar that was superseded by the Gregorian calendar in 1582.
19 Full moon, 4:22 p.m. The full moon of January is called the Wolf Moon, Old Moon and Moon after Yule. The sun enters Capricornus on the ecliptic.
20 The sun enters the astrological sign of Aquarius but astronomically has just entered Capricornus.
22 Moon at perigee or nearest approach to Earth.
25 Look for Saturn to the upper left of the moon in the southeast during the early morning hours.
26 Moon in last quarter, 7:58 a.m.
30 The crescent moon is sandwiched between Venus on its left and Antares on the right about an hour before sunrise.
31 Sunrise, 6:56 a.m.; sunset, 4:42 p.m.