Asteroid 2024 YR4 – Orbital Dynamics and Collisions
2024 YR4’s unpredictable increases in its impact probability underscore the constantly-evolving nature of asteroid monitoring and highlight the value of continuous data collection – essential for refining orbits and assessing possible deflection strategies.
Astronomers continue to monitor a space rock using various telescopes, and have applied for time on NASA’s James Webb Space Telescope in hopes that more observations may reveal lower odds of collision.
Observations
As soon as asteroid 2024 YR4 was discovered, automated systems responded swiftly by notifying astronomers and initiating observations with telescopes around the world. That data has since fed into calculations that enhance predictions of its size and trajectory.
Due to this work, impact probability has fluctuated, recently reaching an all-time record high of 2.6 percent chance in 2032. That number should fall back below one before April, when 2024 YR4 starts its path past Earth and toward Mars on its highly elliptical orbit.
However, the risk is significant: should an asteroid of this size strike Earth it could wreak havoc by devastating cities and infrastructure while injuring or killing thousands. Such a space rock would produce an explosion with fireballs reaching over 130 feet wide — equivalent to roughly two dozen Hiroshima bombs! NASA is actively developing more robust methods for tracking potentially hazardous asteroids like this one.
Orbital Dynamics
Since 2024 YR4’s initial appearance, telescopes across the globe have kept close tabs on it to assess its shape and future path. Astronomers estimate it measures between 40-90 meters wide (130-334 feet) which would cause catastrophic explosions if hit a city; as such it meets criteria to activate the International Asteroid Warning Network’s alerts and world-wide observations system of any asteroid with an impact probability greater than one percent.
Scientists will keep a keen eye on an asteroid until its gradual disappearance in April and beyond, giving scientists one last opportunity to assess its threat before it returns in 2028. NASA’s powerful James Webb space telescope will use infrared observations as it nears, to pin down its size and shape as well as refine orbital dynamics and collision probabilities for this celestial body.
Impact Probability Assessment
Astronomers can only improve their estimates of an asteroid’s impact probability by tracking it with telescopes around the world, which explains why its probabilities swung up and down over time as more data became available.
Asteroid 2024 YR4 may not be large enough to end human civilization, but it could wreak havoc on major cities with airbursts of up to 8 megatons of energy — over 500 times greater than that released by Hiroshima bomb. While such destruction sounds terrifying, its likelihood is currently remote.
Risk will likely remain at or above 1% until late April or early May when it’s expected that the asteroid will fade from view and SMPAG meets to discuss whether any mitigation space missions should be launched against it. Without such missions being launched against it, probability drops below 1% and this highlights why monitoring these asteroids closely is so crucial.
Risk Corridor
Astronomers will continue tracking 2024 YR4 with ground- and space-based telescopes for as long as possible, refining its orbit and evaluating any impact risks it might pose. A collision will only be possible to rule out before April, when 2024 YR4 passes beyond telescopes’ view.
Chances of an impact have peaked at 3.1%; however, that number will likely decrease with additional observations made. As more information becomes available regarding space rocks and their trajectory becomes clearer, chances of strike decrease accordingly.
Risk corridors extend from the Pacific Ocean to South America, across South America and Africa before arriving in Asia. Cities including Bogota, Abidjan, Lagos and Khartoum with populations exceeding one million could all fall within this corridor should an asteroid hit. A collision could create an explosion that surpasses either 1908’s explosion that flattened 830 square miles of forest or 2013’s event that flattened buildings in Chelyabinsk, Russia.