A pair of possibly related comets pass unusually close to Earth.
It is hard to have a personal feel for the microgravity of a comet since it is only a few ten thousandths of the pull of gravity we experience on Earth. When a comet comes near Jupiter or perhaps the Earth the tiny gravity which holds it together can be overwhelmed by gravity of the larger object and the comet's structure disrupted.
Astronomers have observed comets breaking up into smaller pieces as they orbit the Sun. In a spectacular example, more than 20 years ago Comet Shoemaker-Levy 9 became a beautiful string of comets before it crashed into Jupiter.
Recently on two consecutive days, Comet P/2016 BA14 (PANSTARRS) and Comet 252P (LINEAR) both passed within a few million miles of planet Earth. These two objects have remarkably similar orbits which take them from near Earth out to close to the giant planet Jupiter. This situation suggests that the smaller of the two, P/2016 BA14, could be a fragment of Comet 252P which calved off of the parent object during a previous close encounter with Jupiter, Mars, or the Earth.
Currently, Astronomers are using data from the Hubble Space Telescope and NASA's Infrared telescope in Hawaii to look for clues as to the nature of these potentially twin objects.
Comet 252P and P/2016 BA14 will not come this close to Earth again for millennia and are not threat to Earth. What makes them unusual is the opportunity given to humans to study these wanderers of the solar system relatively close up and personal.