As 2020 begins, Venus returns brilliantly to our southwestern evening sky after sunset, and also serves as a guide for sky-watchers to find the most distant planet, Neptune, on the nights of Jan. 26 and 27.
Both planets will appear within the same field of view through a small telescope or binoculars. Since Neptune is so dim we cannot see it without optical aid, having so bright an object as Venus near it in the sky will make seeing it much easier.
To find Neptune, set your telescope at low power or bring your binoculars up on Venus on Jan. 26. Neptune will be just to the right of Venus, appearing as faint dot at magnitude +7.9. There will be a star above Venus, and one to the right of Neptune, so do not confuse them with being Neptune, which will be slightly blue-green.
Neptune will be even closer to Venus on Jan. 27; still to the right and then slightly above Venus, with the star above Venus now appearing just lefts of its position on Jan. 26. Venus of course, at magnitude -4.0 is unmistakable.
This extraordinary conjunction of our brightest planet and our dimmest planet will be enhanced by the slender crescent moon passing just below the pair on Jan. 27.
Although Venus and Neptune appear close together as we gaze out from Earth, they are really very far apart. Venus is 104 million miles away on Jan. 27, while Neptune is 2.5 billion miles away. Both planets just happen to be nearly along the same line of sight from Earth just then.
Next month also boasts the annual Quadrantid meteor shower on Jan. 4; one of the year’s best showers with up to 120 meteors per hour appearing most years. The view is toward the east-northeast around 4 a.m.
The only drawback is that January’s deep winter mornings may be very cold. But do not be discouraged. Be brave and dress warmly.
Once Venus and Neptune have set — by 8 p.m. — there will be no other planets to seek until Mars rises in the east before dawn, 5 a.m. Mars will rise higher and brighten all month, and it will reach its peak for us to see next fall.
On Jan. 22, look southeast about 45 minutes before sunrise for a first glimpse of Jupiter highlighted by a slim crescent moon just to its upper right. Jupiter too will rise to greater altitude in the southeastern sky making it easier to see after midnight through late winter and into the spring.
Saturn remains in the glare of the sun all month, but will appear in the southeast before dawn in February with much better views coming during the spring and the summer.
Earth’s orbit brings it to perihelion when it is closest to the sun on Jan. 5. Earth will be some 91 million miles from the sun then, and nearly 95 million miles from it in July — aphelion.
The full moon occurs on Jan. 10 and the first quarter moon is Jan. 2.