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.
Like buses, you can wait ages for a near-Earth asteroid – then two come along in quick succession. This weekend you also have the opportunity to view a 70-metre-wide space rock known as 2018 RC in backyard telescopes of 6-inch (15-cm) aperture and larger as its hurtles past Earth closer than the Moon.
Possibly as large as The Shard in London, Apollo asteroid 2017 VR12 passes just 3¾ lunar distances from Earth at 7:53am GMT on 7 March. For a few nights, this magnitude +12 space rock is a viable target for small backyard telescopes as it gallops through Coma Berenices and Virgo, passing just 0.8 degrees from Spica on the UK night of 7–8 March.
As darkness falls over Western Europe on the evening of 9 February, near-Earth asteroid 2018 CB lies almost overhead as seen from the UK. We show you how and when to find this 30-metre-wide space rock as it speeds through the constellations of Perseus and Triangulum, passing just one-fifth of the Moon’s distance away at 22:27 UT (10:27pm GMT).
As shooting-star devotees prepare for the naked-eye spectacle of the Geminid meteor shower in mid-December, owners of small telescopes can also witness the close passage of the meteors’ parent body — a curious “rock comet” known as 3200 Phaethon, galloping through the constellations of Auriga, Perseus, Andromeda, Pisces and Pegasus at a rate of up to 15 degrees/day.
At 6:42am BST on Thursday, 12 October our best orbit prediction for a 20-metre-wide space rock designated 2012 TC4 indicates that it will hurtle by Earth just 43,800 kilometres (27,215 miles) above the ocean between Australia and Antarctica. If UK skies are clear on 11 October and you have an 8-inch or larger telescope, you might just see it too.
During the first week of September, observers have an opportunity to see a bright near-Earth asteroid known as 3122 Florence (aka 1981 ET3) as it sails by our planet. On the night of 2—3 September, observers in the UK and Western Europe can see this 4.4 kilometre-wide space rock pass through a prominent asterism in the constellation of Delphinus, the dolphin.
Five hundred-metre-wide asteroid 2017 CS passes just 1.9 million miles, or 7.9 lunar distances, from Earth on the afternoon of Monday 29 May 2017. For a few nights around this date, Northern Hemisphere observers with 6-inch and larger ‘scopes can see the asteroid gallop through the constellations of Canes Venatici, Boötes and Hercules at up to 14 degrees/day.
A peanut-shaped asteroid almost a mile long known as 2014 JO25 passes within 5 lunar distances of Earth on 19 April — the closest any known space rock of this size has approached our planet since September 2004. We show you how to find this fast-moving potentially hazardous asteroid in small telescopes during the UK night of 19-20 April.