Their high detection rate reveals that near-Earth asteroids are commonplace, but they’re typically small, fleetingly observable and very faint. Hence an opportunity to view a large example bright enough to see in a typical backyard telescope shouldn’t be missed! Here’s our guide to tracking down 700-metre-wide 1998 HL1 between 25 and 29 October 2019.
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.