If any clear skies occur during the last week of October, don’t miss any opportunities to view a 700-metre-wide space rock with the catchy designation 162082 (1998 HL1) as it hurtles past our planet slightly more than sixteen lunar distances away at 17:20 UT (6:20pm BST) on 25 October 2019.
Predicted to reach a peak magnitude of +12.4 on 27 October, this near-Earth asteroid is a viable target for 6-inch (15-cm) aperture telescopes and larger for five nights as it zips through the constellations of Triangulum, Aries and into Cetus at rates of up to 9 degrees/day relative to the background stars. (See the bottom of this page for a table of predicted positions at hourly intervals for observers in the UK and Western Europe.)Although classified as a Potentially Hazardous Asteroid (PHA), there is no chance that 1998 HL1 could collide with Earth for at least 120 years. The next time it passes closer to Earth than this apparition is on 26 October 2140 when it zips by our planet at a distance of 6.18 million kilometres, or 3.8 million miles.Discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) project at Socorro, New Mexico on 18 April 1998, 162082 (1998 HL1) is an Apollo-type asteroid that loops the Sun once every 508 days in an eccentric orbit inclined by 20 degrees to the ecliptic.
A small asteroid designated 2016 HO3 has been discovered in an orbit around the Sun that keeps it as a constant companion of Earth, and it will remain so for centuries to come. It is too distant to be considered a true satellite of our planet, but it is the best and most stable example to date of a near-Earth companion, or “quasi-satellite.”
Have you ever seen the closest planet to the Sun? If you wish to tick Mercury off your To-See list, particularly if you live in the Southern Hemisphere, now until the middle of May is the time to be scrutinising the eastern sky about an hour before sunrise. Mercury also has a close encounter with an old crescent Moon on 14 May.
On 26th January, asteroid 2004 BL86 will pass Earth just three lunar distances away. It will be the closest approach by any known space rock this large until asteroid 1999 AN10 flies past our planet in 2027.