Over the next two days a pair of comets will make dual close proximity flybys of Earth. It is theorized that at some point the comets had formed a single body, which may have fractured in two as it traveled through the solar system.
The first of the twin comets, 252P/LINEAR, was discovered on April 7, 2000, by Massachusetts Institute of Technology's Lincoln Near Earth Asteroid Research (LINEAR) survey. At the time 252P/LlNEAR was believed to be a lone wanderer.
However, the discovery of the comet P/2016 BA14 on January 22, 2016, following a suspiciously similar trajectory to 252P/LINEAR has led some to theorize that the bodies used to form a single unified comet.
At some point in its history, the progenitor comet must have somehow fractured in two, resulting in the smaller P/2016 BA14 body splintering away from 252P/LINEAR, which according to recent observations is around twice the size of its smaller cousin.
Observations made of the comet Shoemaker-Levy 9 prior to its impact with Jupiter in 1994 support the premise of the theory by exemplifying a scenario in which the influence of a very large solar system body, in this case Jupiter, succeeded in fracturing a comet into numerous pieces.
252P/LINEAR will be the first comet to buzz Earth, with the point of closest approach occurring today at a distance of 3.3 million miles (5.2 million km) at approximately 8:14 am EDT. On March 22, the smaller comet P/2016 BA14 will safely glide by at a distance of 2.2 million miles (3.5 million km), with closest approach estimated for 10:30 am EDT.
Unfortunately, neither pass will be visible to the naked eye due to the diminutive sizes of the comets, though the flybys may be observable to astronomers with heavy duty telescopes. Regardless of the underwhelming visual impact of the events, the pass of P/2016 BA14 will be recorded in the history books as the third closest flyby of a comet in recorded history.
Follow up observations of the twin comets are set to be made by the Hubble Space Telescope and NASA's Infrared Telescope Facility in an attempt to determine whether the comets did indeed originate from a single larger body.
For members of the public concerned about just how close the duo will come on their next pass there is no need to worry, as the March 22 pass is predicted to be the closest the comets will come to Earth in the next 150 years.