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Asteroid deflection technologies

Asteroid deflection technologies are methods and strategies developed to prevent potential impacts of asteroids with Earth. These technologies aim to alter the trajectory of an asteroid to ensure it does not collide with our planet Following the success of NASA's DART (Double Asteroid Redirection Test) mission, discussions about planetary defense and asteroid deflection strategies are increasingly prominent. Here are some principal methods and how they work: 1. Kinetic Impactor:    - How It Works: This method involves sending a spacecraft to collide with an asteroid at high speed. The impact changes the asteroid's velocity and trajectory, ideally enough to avoid a collision with Earth.    - Example: NASA's DART (Double Asteroid Redirection Test) mission successfully demonstrated this technique by impacting the moonlet Dimorphos in 2022. 2. Gravity Tractor:    - How It Works: A spacecraft positioned near an asteroid uses its gravitational pull to...

Why the day is 24 hours long: Astrophysicists reveal why Earth's day was a constant 19.5 hours for over a billion years

Astrophysicists have revealed how the slow and steady lengthening of Earth's day caused by the tidal pull of the moon was halted for over a billion years. They show that from approximately two billion years ago until 600 million years ago, an atmospheric tide driven by the sun countered the effect of the moon, keeping Earth's rotational rate steady and the length of day at a constant 19.5 hours. Without this billion-year pause in the slowing of our planet's rotation, our current 24-hour day would stretch to over 60 hours. The paper offers a new perspective on how global warming will affect the length of our day and validates global circulation models as a climate modelling tool.

from Space & Time News -- ScienceDaily https://ift.tt/El7VTeR

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