* The Earth would spiral inwards towards the Sun. Orbital velocity is what keeps Earth from falling directly into the Sun. A slower velocity means the Earth's gravitational pull towards the Sun is stronger than its outward momentum, causing it to spiral in.
* The orbit would become more elliptical. The shape of Earth's orbit would change from its current near-circular shape to a highly elliptical one. This means that Earth would experience periods of extreme closeness to the Sun (perihelion) and extreme distance from the Sun (aphelion).
* Temperatures would fluctuate wildly. The drastic changes in distance from the Sun would lead to extreme variations in Earth's temperature. During perihelion, the Earth would experience intense heat, while during aphelion, it would experience extreme cold.
* Life on Earth would likely cease to exist. The drastic changes in temperature and the unpredictable nature of the new orbit would make it impossible for most life forms to survive.
It's important to note that this scenario is purely hypothetical. Halving Earth's velocity is not something that could happen naturally, and it's unlikely that any event could cause such a drastic change. Earth's current orbit is incredibly stable and has been relatively consistent for billions of years.
