3 Planets Align in Rare Sky Show

Three planets won't be this close to each other again until 2021.

— -- The eastern sky plays host this week to a cosmic show that hasn't been seen in two years and won't be seen again for another five years.

According to EarthSky.org, the closest grouping of this trio was this morning around dawn, though you can spot the trio every morning through October 29. In order to view the trio, just look towards the east. The best time to catch this planetary grouping will be about an hour before sunrise, when even the relatively dim planet Mars is most visible to the naked eye.

While these planets might look close to each other from Earth, in reality they are separated by hundreds of millions of miles. NASA says that these kinds of celestial events "have no real astronomical value," but they are still pretty cool to witness.

In addition to the planetary trio, October 26 also marks Jupiter's greatest western elongation -- in other words, Jupiter is at its farthest from the sunrise on this date. Jupiter will also be officially in conjunction with Venus on October 26, meaning that the two planets will have the same right ascension, the celestial equivalent of longitude.

While the conjunction of planets isn't extremely rare, EarthSky says that the next planetary trio won't happen until January 2021.