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The moon will be closest to Earth at 7:32 a.m EDT on June 23, but you will be able to see the supermoon shining bright on Saturday, June 22 as well.
Sunday's supermoon will appear 14 percent larger and 30 percent brighter than a regular full moon does,
The June supermoon will be the largest one in 2013 — the moon won't come this close to Earth again until August 2014 — but you can expect another supermoon on July 22. The last supermoon was on May 25.
While a supermoon does bring extra-high tides, the extra gravitational force is not big enough to produce any significant changes in seismic activity for those who are concerned that the moon's close proximity to Earth will trigger earthquakes and volcanic eruptions.