Asteroid YR4 Raises 4% Collision Risk
Asteroids in Earth's orbit hide in Sun's glare, limiting detection windows.
140-metre asteroid strike equals 300 million tons of TNT energy.
Asteroid YR4 passed Earth on Dec 25, 2024, with 4% collision risk for 2032.
NASA lacks immediate defense against mid-sized 140m asteroids.
DART mission is a one-off demo with no immediate launch options.
3 hours ago