This image, captured by NASA’s Hubble Space Telescope, shows the first observed interstellar comet to enter the solar system as it speeds past the sun at 160,000 kilometres per hour. It is the closest comet 2I/Borisov has come to the sun since Hubble started tracking it in October.
The latest image from the telescope shows that Borisov is currently about 300 million kilometres away from Earth. It will approach slightly closer to our planet in late December, getting within about 290 million kilometres.
☄️ A mysterious visitor from the depths of space, interstellar comet 2I/Borisov, was captured by @NASAHubble speeding away from our solar system. This Dec. 9 photo shows the comet after close approach to the Sun where it reached a max speed of 100,000 mph: https://t.co/8sER0J72aT pic.twitter.com/J5iXwk21Q8
— NASA (@NASA) 12 December 2019
Recent observations of Borisov suggest that its nucleus – the mass of ice and dust particles and the comet’s centre – is only 1 kilometre long, which is about 15 times smaller than astronomers thought it would be. Knowing its size might help to predict how common comets and other objects are in the solar system.
Borisov is only the second interstellar object ever seen entering the solar system – the first was ‘Oumuamua in 2017. The comet will pass Jupiter in mid-2020 before making its way back to interstellar space and remaining there for billions of years.
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