Two comets make close approach of Earth
Two comets with remarkably similar orbits have safely flown past the Earth this week. The similarity of their orbits and the difference in their sizes indicate that the smaller of the two comets may have calved off of the larger one, making them twins of a sort.
Comet P/2016 BA14 was discovered on January 22, 2016, by the University of Hawaii’s Pan-STARRS telescope on Haleakala, on the island of Maui. It was originally thought to be an asteroid, but follow-up observations by a team of the University of Maryland and Lowell Observatory astronomers using the Discovery Channel Telescope revealed the presence of a faint tail. Comet P/2016 BA14 follows an orbit that is surprisingly similar to that of Comet 252P/LINEAR, which was discovered by the Massachusetts Institute of Technology’s Lincoln Near-Earth Asteroid Research (LINEAR) survey on April 7, 2000.
“Comet P/2016 BA14 is possibly a fragment of 252P/LINEAR. The two could be related because their orbits are so remarkably similar,” said Paul Chodas, manager of NASA’s Center for Near Earth Object Studies (CNEOS) at the Jet Propulsion Laboratory in Pasadena, California. “We know comets are relatively fragile things, as in 1993 when Comet Shoemaker-Levy 9 was discovered and its pieces linked to a flyby of Jupiter. Perhaps during a previous pass through the inner Solar System, or during a distant flyby of Jupiter, a chunk that we now know of as BA14 might have broken off of 252P.”
The Hubble Space Telescope will observe comet 252P/LINEAR, and NASA’s Infrared Telescope Facility will study Comet P/2016 BA14. These investigations of the two comets may yield more information about their possible twin nature.
Comet 252P/LINEAR, which is about 750 feet in size (230 meters), had its closest approach to Earth, a range of about 3.3 million miles (5.2 million kilometers), at 8:14 a.m. EDT on Monday, March 21. Comet P/2016 BA14, which is roughly half the size of 252P/LINEAR, made its closest approach, a range of 2.2 million miles (3.5 million kilometers), on March 22 at 10:30 a.m. EDT. This was the third closest flyby of a comet in recorded history.
This week’s approaches were the closest that the two comets have passed Earth and will be for the foreseeable future.
“March 22 [was] the closest [that] comet P/2016 BA14 [got] to us for at least the next 150 years,” said Chodas. “Comet P/2016 BA14 [was] not a threat. Instead, it [was] an excellent opportunity for scientific advancement on the study of comets.”
The CNEOS website has a complete list of recent and upcoming close approaches, as well as all other data on the orbits of known NEOs. In January, NASA formalized its ongoing program for detecting and tracking of NEOs as the Planetary Defense Coordination Office (PDCO).
Jim Sharkey is a lab assistant, writer and general science enthusiast who grew up in Enid, Oklahoma, the hometown of Skylab and Shuttle astronaut Owen K. Garriott. As a young Star Trek fan he participated in the letter-writing campaign which resulted in the space shuttle prototype being named Enterprise. While his academic studies have ranged from psychology and archaeology to biology, he has never lost his passion for space exploration. Jim began blogging about science, science fiction and futurism in 2004. Jim resides in the San Francisco Bay area and has attended NASA Socials for the Mars Science Laboratory Curiosity rover landing and the NASA LADEE lunar orbiter launch.