2014 JO25 will pass 4.57 lunar distances from Earth on April 19, 2017 at 12:24:25 UTC. While asteroids pass this close to Earth every few days, 2014 JO25 is notable because of its size: over a half a kilometer. Most asteroids are only a few meters across. The last time a large asteroid came this close to Earth was 2004, when 5-km Toutatis passed Earth at a four lunar distances.
At its closest, 2014 JO25 will brighten to magnitude 11, bright enough to see in small telescopes. It will continue to brighten to about magnitude 10.7 after close approach, as its phase angle increases. Six hours after closest approach, while at its brightest, it will pass the handle of the Big Dipper at about 18:30 UTC. It might be bright enough to follow in a good pair of binoculars.
2014 JO25 has a period of about 3 years and is currently locked in a 4:1 resonance with Jupiter.
Here are links to the simulations that produced the animations in this post. They will run in your web browser.
A view from Earth following 2014 JO25‘s path across the sky.