It’s mid-September 2084. Thanks to politicians listening to activists and scientists, we have avoided the worse of the climate crisis. You’re enjoying a nice cup of tea on your patio, and then bam! An asteroid explodes overhead. Your morning is ruined.

Alright, we let ourselves get carried away with that fantasy (especially the part about the politicians), but a newly discovered building-sized asteroid, 2019 SU3, will indeed have a close encounter with our planet in 65 years. Based on the current orbital parameters, it will be within 10,000 kilometers (6,000 miles) from the surface of the planet.

The chance that it will actually hit our planet is between unlikely and very unlikely, with the most pessimistic scenario giving it a one in 147 chance, while others suggest that it is more of a one in 3,600 chance. The European Space Agency has added 2019 SU3 to the list of risky objects simply to make sure to refine the measurements.

Uncertainties are all too common when it comes to predicting the orbits of asteroids in the far future. For example, the date is not set in stone, with the tentative timing between September 16 and September 21, 2084. The estimations for the future movements are based on 124 observations and more are needed. Luckily, it will come close (but not dangerously close) several more times before 2084.

So what would happen if the object was actually on a collision course with Earth? Well, it would likely produce a bolide similar to the Chelyabinsk meteor that exploded over Russia in 2013. The size estimates for 2019 SU3 put it at between 9 and 23 meters (30 to 75 feet) – roughly the expected size of the Russian object.

The Chelyabinsk asteroid burned up high in the atmosphere, with the shockwave it produced damaging over 7,000 buildings and injuring 1,491 people from the glass of exploded windows.

While it might not be an extremely dangerous object, 2019 SU3 is another reminder of how much we don’t know about the space rocks out there. It was only discovered on September 23, a few hours before it passed close to Earth.