Depending on where you are in the world on Wednesday night (September 14), you may be able to see Uranus vanish. (Don’t worry, it’ll be back a few hours later.)
On Wednesday, the sixth planet from Sun will appear to pass directly behind the Earth Moon, completely disappearing from sight for three and a half hours. The great disappearing act, also known as the lunar occultation of Uranus, begins around 4:41 p.m. ET (2041 GMT) and ends at 8:11 p.m. ET (0011 GMT on September 15), according to In-the-sky.org. However, only viewers in Europe, North Africa and West Asia will be at exactly the right angle to see how the illusion works.
Viewers in these regions will still need binoculars or a telescope to see the show, as Uranus is not a planet with the naked eye. (Check this mapcourtesy of In-the-sky.org, to see which regions will have the best views).
If you’re not in one of those places or don’t have a telescope, don’t worry; you can see the occultation live from Rome thanks to the Virtual Telescope Projectwhich will begin broadcasting the event at 4:45 pm ET (20:45 GMT).
Occultation refers to any astronomical event in which one object appears hidden behind another. This phenomenon is slightly different from an eclipse, which occurs when one object casts its shadow directly onto another, such as when the moon’s shadow falls on Land during a solar eclipse.
From Earth, lunar occultations are seen most often, since the Moon looms so large in our sky. However, the moon’s proximity to Earth also means that its position in the sky may appear slightly different depending on which part of the planet you’re observing from. As such, all lunar occultations are visible only to narrow swathes of the world that have the exact viewing angle.
Fortunately, these events are frequent, so another lunar disappearing act is always just around the corner. The last lunar occultation of Uranus that was visible from the United States and Canada occurred last month, on August 18, WordsSideKick.com sister site Space.com reported. Uranus emerged triumphant that night, and will surely do so tomorrow as well.
Originally published on Live Science.