Two small asteroids whiz by Earth today, even closer than the last

Asteroid 2014 DX110 tumbled past the Earth on Wednesday evening, just inside the orbit of the moon, as astronomers on the ground watched it safely fly by. Now, hot on its 'heels' are two more newly-discovered asteroids, both of which are going to come even closer to the Earth.

The first of these, named 2014 EF — estimated at about 4-9 metres wide and around 400-500 metric tons — actually flew past us late last night, at around 10:20 p.m. Eastern Time (3:20 UTC today). It was spotted very early Wednesday morning, by the Catalina Sky Survey, and it passed by us at a distance of around 150,000 kilometres, or roughly two-fifths of the distance to the moon.

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The next one, named 2014 EC, was also spotted early Wednesday morning by the Catalina Sky Survey, just shortly before its predecessor. 2014 EC is a bit bigger, between 6-14 metres wide and estimated at 600-700 metric tons, and it's flying past at roughly 57,000 kilometres per hour. It's passing by Earth later today, even closer than 2014 DX110 did yesterday and 2014 EC did last night. At its closest, it will be just 61,500 kilometres away, or just over 15 per cent of the distance to the moon.

However, even with these asteroids coming that close, it's still a virtual certainty (greater than 99.99 per cent chance) that they will miss us. According to NASA's Jet Propulsion Laboratory, we'll be seeing at least 2014 EC from time to time after this, though. They currently have 25 separate potential impacts from this asteroid between the years 2025 and 2105. Still, the cumulative probability of impact is only about 1 in 2.7 million (so pretty long odds) and astronomers say that it will likely be completely removed from the risk tables once they have more observations.

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Seeing these asteroids with only one day's notice before they pass may seem like cutting it very close, but it's very difficult to detect asteroids of this size. Taking 2014 EC as an example, it was spotted when it was still roughly 2 million kilometres away from us. That's the equivalent of scanning the horizon with a pair of binoculars and spotting a grain of sand being blown on the wind, 200 kilometres away. So, it's really showing how skilled astronomers and automatic surveys have gotten at seeing these. In years past, we'd have never seen it at all, or we'd have only known about it after it passed us by.

The Slooh Space Camera astronomers did see 2014 DX110 yesterday, by the way. So it didn't go missing, like 2000 EM26 (nicknamed 'Moby Dick' by Slooh) did a few weeks ago. The video below shows a nine-frame loop of 2014 DX110 (the long streak in the middle) as it flew past. It isn't resolved as just a pin-point in the images because it's moving so quickly.

(Image courtesy: Getty)

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