Predictions are for a half-dozen binocular comets in 2017!
Comet (C/2016 U1) NEOWISE
Comet (C/2015 ER61) PanSTARRS
Comet (C/2015 V2) Johnson
Sky & Telescope has more information at this link:
S&T Comets for 2017
Comet 45P/HONDA–MRKOS–PAJDUŠÁKOVA breaks the dry spell of comets for 2016 as it gradually brightens above our southern horizon. It is expected to reach maximum brightness around late February 2017. Discovered independently by astronomers Minoru Honda, Antonin Mrkos and L’udmila Pajdušáková on December 3rd, 1948, Comet 45P/Honda-Mrkos-Pajdušáková orbits the Sun once every 5.25 years on a short period orbit. Comet 45P/ is set to break binocular +10th magnitude brightness in mid-December 2016, and may reach a maximum brightness of magnitude +7 from January through February 2017. It should become very briefly visible in the last part of December before getting too close to the Sun to observe and crossing into the morning sky in early 2017. Th best viewing when the comet is at its brightest will be in late January and February in the morning sky.
A Universe Today article is available here: Comet 45P/
An article from Brian Ventrudo is available here: Cosmic Pursuits Comet 45P
Comet 2P/Encke completes an orbit in a hurry, just 3.3 years. Encke always begins its apparition as a faint, diffuse mist but wastes no time brightening and compacting into a fine little comet suitable for small telescopes. The comet was recently snared by visual comet observers in December, but it still shines wanly at magnitude +12 at this writing. Watch for it to brighten to magnitude +9 by mid-February as it cracks the whip around the Circlet asterism in Pisces at nightfall. Soon after, Comet Encke plunges south and becomes lost in evening twilight by early to mid-March even as it swells to a predicted magnitude of ~6.5.
Comet C/2015 ER61 (PanSTARRS) has created a flurry of excitement with some estimating its peak magnitude as bright as +2. Discovered as an asteroid in 2015, it was later shown to exhibit a coma and renamed as a comet. Most sources I've checked, including Seiichi Yoshida's excellent Weekly Bright Comets and JPL's Horizon site, put C/2015 ER61 at magnitude +7 from mid-April through mid-May. No complaints here. Any comet visible in binoculars is a gift, and every one of them looks even more amazing in a telescope. Still, some may struggle to find this cotton ball. Why? C/2015 ER61 has a serious altitude problem for observers at mid-northern latitudes throughout its apparition. The comet tracks along the ecliptic never far behind the Sun. This month, the 30″ diameter, 13th-magnitude comet creeps from Libra into Scorpius, keeping observers at bay until the very start of dawn, when it finally reaches a somewhat reasonable height above the horizon. When brightest in May, it will be crossing from Aquarius to Pisces.
Comet C/2015 V2 (Johnson) may put on a nice show in May and June. It is predicted to peak around magnitude +6.5 in early June as it slides down the eastern side of Boötes high in the southern sky before the mosquitoes return. Currently at magnitude +11.5, 1′ in diameter and moderately condensed, this comet is warming up for its spring performance in the morning sky in northern Boötes. An 8-incher should coax it into view using magnifications of 100× and higher.
Comet 41P/Tuttle-Giacobini-Kresak I saved what might become the brightest comet for last, and we touched on this one in a blog last November as one of the three periodic comets that are making extremely close passes of Earth in the next two years. Come April, as it tears across the northern circumpolar sky, it may max out at magnitude +6 and become faintly visible with the naked eye under rural skies. While that's exciting enough to contemplate, this comet is known for outrageous outbursts. Twice in 1973 it underwent 10-magnitude eruptions! More recently, in December 2001, it shot up three magnitudes unexpectedly. Watch out for this live wire!
Universe Today writer David Dickinson has an update for this comet here: Universe Today Comet 41P
For up-to-date information on all the recently discovered comets, check this excellent website: http://www.aerith.net/comet/weekly/current.html . Screen snap below is from Seiichi Yosida's website and illustrates the brightest comets in the sky presently. More information including brightness prediction graphs are found at the website. All graphics and information is by Seiichi Yoshida and is provided with his kind permission. Screen snap below was obtained Feb 25, 2017.
Our Next Great Comet is OVERDUE!
Tim Reyes writes for EarthSky.org. One of his recent excellent articles is called "When is Our Next Great Comet?" An interesting read!