Comet ISON, the 'comet of the century', has suddenly ignited and is now visible to the naked eye.
Astronomers have confirmed that the potentially staggering comet has massively increased in brightness in recent days and can now be seen without the aid of a telescope or binoculars - if you know where to look.
Check out our guide on how to see the comet if you want to get a good look this weekend.
Space.com reported that the comet is now in "full outburst mode" having increased in brightness by a magnitude of two in just 24 hours. It's now within the threshold of being visible to the naked eye in the night sky.
In 72 hours the comet has increased in brightness by a factor of 16.
The comet is now approaching the surface of the Sun, and could potentially brighten every day until the end of November - that is if it doesn't fall apart or explode before then.
If it lasts, the comet could shine as brightly as the Moon - or brighter - in the night sky, and could even be visible during the day.
Veteran comet hunter John Bortle told Space.com: "I couldn't figure out what the funny-looking, blotted, star that came into view was. [Was my] seeing that bad? But, no, the 'blotted star' was, in fact, at the comet's position!"
It's not currently known if the comet will continue to brighten. It has fluctuated in brightness before - though never to this extent. Astronomers now hope we could be on the verge of something spectacular...