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UPDATE : A meteor shower from C/2015 D4 (Borisov) on July 29?
Discovered on 2015, February 23rd, by Gennady Borisov, the comet C/2015 D4 (Borisov) is a long-period one, which will be back in the inner Solar system in more than 200 years. Its last perihelion was thus in October 2014, just before it was discovered. Its orbit has been better defined now, and recent research directed by Peter Jenniskens and Esko Lyytinen shows that this object may be the source of a meteor shower that could display activity this year, at the end of July.
Distance between the earth and the position of the 1-rev dust trail from C/2015 D4 (Borisov) as a function of time. The 2017 configuration is favorable due to the combination of two factors: the short distance (0.0006 AU) of the trail, and the short time period after the comet perihelion. Credit: Esko Lyytinen, Peter Jenniskens
According to their model, on July 29th, 2017, around 00h 22min UT, the Earth will cross very close to the orbit of the comet, and thus to the center of the dust trail, as it will pass only 0.0006 AU (less than 90 000 km) inside the comet's orbit. Combining this close approach with a timing not that far from the last perihelion of the comet leads to a potential activity of a new meteor shower, whose radiant would be positioned at (RA ~ 79° (05h 15min) ; Dec. ~ -32°), and whose meteoroids would have an entry velocity around 46 km/s. The radiant is located in the constellation Columba, and is very close to the Sun. Activity should be hard to be detected visually, but radio methods should work to monitor any activity at the predicted time, if you are well located! Because the activity of this shower should not last very long (it seems unlikely that this activity would exceed 2 hours), Southern hemisphere observers should be aware of any potential activity around the time indicated above, and should not miss it!
Past enhanced activity could also have occurred on 2006, July 9th, and some other activity enhancements could occur in the future, but not before 2042, 2053 or 2068!
More information on the CBET 4403
UPDATE (26/07/2017): according to Peter Zimnikoval, seen the astronomical configuration, chances are slight (but they exist) that some lunar impacts linked to C/2015 D4 (Borisov) released meteoroids could be observed on the dark side of the Moon. Impats may not be visible if meteoroids are too small, but please be aware of this possibility, especially for observers located Southern and Central America, as well as Southern Florida, where the Moon will be visible during the expected enhanced activity.
Impact geometry on the Moon surface for potential meteorods issued from comet C/2015 D4 (Borisov), on July 29th, 00h 22min UT, during the potential enhanced meteor activity. Credit: Peter Zimnikoval (using MetShow)