3 ms·

I'm pretty sure the Tunguska event was an asteroid aero-braking into the ground. Where are you going to put the kinetic energy? Once it hits atmosphere there's

I'm pretty sure the Tunguska event was an asteroid aero-braking into the ground. Where are you going to put the kinetic energy? Once it hits atmosphere there's not a lot you can do. Maybe attach a really big parachute.

Symmetry 8y ago
The speed at which energy is released varies by altitude and speed. The Tunguska asteroid managed to reach just 10 km over the Earth's surface before exploding where the air is getting quite thick. What you want to do is rather than dive in head first just skim the atmosphere and drain your energy bit by bit. Once you're going slowly you can afford to go lower without burning up. When astronauts return from space they have to carefully control how they descend and make sure that they don't get too low while they're traveling too fast. Otherwise they'd burn up.
- orbital-decay 8y ago
  Gliding/skipping entry is not feasible for such a massive, unpredictable and uncontrolled object. Both due to accuracy and aerothermodynamics. Thermodynamically speaking, entry angle is a trade-off between the peak heat load and the total heat received, and for the prolonged reentry the object has to be engineered to radiate much more heat away than with a steeper angle entry. Also, skipping entry is extremely inaccurate, and must be precisely controlled to achieve the desired result.
  - cfadvan 8y ago
    This all assumes that for some strange reason you’re dropping the whole asteroid rather than packets of pre-processed material which is what you’d actually do. As a bonus you could use some of the cruft from the original body to make heat shielding for the “parcels” to be used on reentry.
    - Gravityloss 8y ago
      You can shape the thing so it slows down to a lowish terminal velocity. Think of a wide shallow cone shell with rounded tip. Or even a hollow sphere.

3 ms·

I'm pretty sure the Tunguska event was an asteroid aero-braking into the ground. Where are you going to put the kinetic energy? Once it hits atmosphere there's

by jschwartzi 8y ago

Symmetry 8y ago
The speed at which energy is released varies by altitude and speed. The Tunguska asteroid managed to reach just 10 km over the Earth's surface before exploding where the air is getting quite thick. What you want to do is rather than dive in head first just skim the atmosphere and drain your energy bit by bit. Once you're going slowly you can afford to go lower without burning up. When astronauts return from space they have to carefully control how they descend and make sure that they don't get too low while they're traveling too fast. Otherwise they'd burn up.
- orbital-decay 8y ago
  Gliding/skipping entry is not feasible for such a massive, unpredictable and uncontrolled object. Both due to accuracy and aerothermodynamics. Thermodynamically speaking, entry angle is a trade-off between the peak heat load and the total heat received, and for the prolonged reentry the object has to be engineered to radiate much more heat away than with a steeper angle entry. Also, skipping entry is extremely inaccurate, and must be precisely controlled to achieve the desired result.
  - cfadvan 8y ago
    This all assumes that for some strange reason you’re dropping the whole asteroid rather than packets of pre-processed material which is what you’d actually do. As a bonus you could use some of the cruft from the original body to make heat shielding for the “parcels” to be used on reentry.
    - Gravityloss 8y ago
      You can shape the thing so it slows down to a lowish terminal velocity. Think of a wide shallow cone shell with rounded tip. Or even a hollow sphere.