Comet 252P/LINEAR will zip past Earth on Monday, 21 March at a range of about 3.3 million miles. The following day, comet P/2016 BA14 will safely fly by our planet at a distance of about 2.2 million miles, or nine times the distance to the Moon. This will be the second closest flyby of a comet in recorded history next to comet D/1770 L1 (Lexell) in 1770.
NASA has formalised its ongoing program for detecting and tracking near-Earth objects (NEOs) as the Planetary Defense Coordination Office (PDCO). The office will be responsible for supervision of all NASA-funded projects to find and characterise asteroids and comets that pass near Earth. It will also take a leading role in coordinating efforts in response to any potential impact threats.
Somewhat appropriately spooky for Halloween in recent radar images, 600 metre-wide near-Earth object 2015 TB145 dashes by our planet today. Now believed to be a dead comet that has shed its volatiles after numerous passes around the Sun, the object makes its closest approach to Earth at 5pm GMT. UK observers with clear skies may see it with modest telescopes in the early evening.
Five bodies in our Solar System are known to bear rings — Saturn, and to a lesser extent, rings of gas and dust also encircle Jupiter, Uranus, and Neptune; then Chariklo was added this haloed group last year, one of a class of minor planets called centaurs — now the progenitor of the centaurs, Chiron, most likely has rings too.