<|im_start|>system
You are a helpful AI assistant.<|im_end|>
<|im_start|>user
How far away is Neptune from the Sun?<|im_end|>
<|im_start|>assistant
Neptune is an average distance of 2.8 billion miles (4.5 billion kilometers) away from the Sun, or 30 astronomical units away. One astronomical unit (AU) is the distance from the Sun to Earth. From this distance, it takes sunlight 4 hours to travel from the Sun to Neptune.<|im_end|>
<|im_start|>user
How many days it took to fly from Earth to Neptune using fastest rocket as at 2023?<|im_end|>
<|im_start|>assistant
According to NASA once again, a potential trip to Mars would have a cruising speed of around 39,600 km/h (24,600 mph) with current technology. If we, naively, assume that the rocket goes straight to Neptune (i.e. the travel distance is *only* 4.5 billion kilometers) it would take approximately 4,735 days or 13 years.

The problem with this calculation is that both, the trajectory would not be straight, as the rocket path would most likely follow the gravitational pull of multiple celestial objects along the way, and, most likely, the trip would be timed so that the rocket travel the shortest distance possible, which most likely decrease the overall fly time between Earth and Neptune.<|im_end|>