ASTEROID
Will the Earth be destroyed by an asteroid in 2038 (DESTROY EARTH IN 2038) has become one of those subject areas which resonates with a lay public as well ongoing debate, fear and drill down analysis?
This article looks into the specifics of this potential danger, why it is a possibility and what humans are doing to defend themselves against such.
Understanding the nature of asteroids, their impact potential and specifics about this individual asteroid is very important to understand what we may be up against in a not-too-distant future.
Understanding Asteroids
Asteroids are rocky objects orbiting the sun, mainly concentrated in an asteroid belt between Mars and Jupiter.
These bodies go from little rocks to a few kilometers’ vast objects. Then there are some that get nudged into different paths by the gravitational effects of planets, and eventually they end up much closer to us.
It is potentially catastrophic for an asteroid to be in the orbit of Earth, due its trajectory which may intersect with that of our planet.
Effects of Asteroid Collision
Asteroid collision is one of the most deplorable events in which Earth could get caught.
The effects of such an impact could potentially cause widespread damage and death over a wide area, long-lasting environmental consequences, in accordance to the size and velocity of the asteroid.
To get an idea, the asteroid that wiped out the dinosaurs 66 million years ago is thought to have been around 10 kilometers wide.
That collision energizes which equals to millions of nuclear bombs exploded with the force blanketing the planet, unleashing shockwaves and tsunamis that cause global fires.
Even smaller asteroids, such as the one that blasted apart over Chelyabinsk, Russia in 2013 can wreak havoc.
The asteroid that exploded over Chelyabinsk in 2013 was approximately 20 meters across and produced an energy yield comparable to about half a megaton of TNT, leaving more than fifteen hundred injured victims from broken glass shockwaves and thousands of buildings damaged.
The Reality of the 2038 Asteroid
One such example is asteroid 2001 WN5, which has from time to time made headlines in the news because of its close encounter with Earth forecast for later this century.
Discovered in 1998, it is a rocky body about one kilometer wide—a size large enough to create regional effects if colliding with Earth.
The obvious question is whether it will hit us?
Heath and Durda did orbital calculations on the asteroid survivor from Earth, as well as suggested impact probabilities.
2001 WN5 has been tracked by NASA as well as other space agencies with the use of sophisticated telescopes and radar systems.
As now predicted, the nearest approach to Earth will occur in 2038 when the asteroid is within a few hundred thousand kilometers of our planet – closer than our Moon. That may sound scary, but remember that “close” is a relative term in astronomical terms.
There are currently odds less than 1 in 100,000 that the more massive asteroid will crash land on Earth when it returns to Earth near year’s end.
That assessment depends on fine-tuning of the asteroid’s velocity, path and its likely encounters with Earth-gravitational fields along that upcoming pass.
Still, those predictions are not quite certain — the smallest gravitational interactions or non-gravitational forces (such as the Yarkovsky effect) that change an asteroid’s course could supersede our forecasts completely.
The Yarkovsky Effect: A Gentle Force
The Yarkovsky effect is an important long-term dynamical influence that continuously changes the trajectory of asteroids over time through a phenomenon where solar energy can cause them to slightly change their orbit by absorbing and re-emiting sunlight.
As the asteroid spins, it gets hot during its daytime and cools down at night causing irradiation in infrared. This radiation applies a small but continuous pressure on the asteroid, which over time nudges it in its orbit.
The Yarkovsky effect can change an asteroid’s orbit over decades or centuries, which makes long-term predictions difficult.
How the Threat is Being Managed
In light of the potential hazards, space agencies around the world have been working to resolve this issue and come up with plans that could help in preventing an asteroid strike.
Those efforts include the work of identifying and tracking a potentially hazardous asteroid.
Early Detection and Tracking
One is early detection, the ability to run fast enough that we find and preemptively do something about an asteroid impact.
NASA’s Near-Earth Object Observations Program and its international partners have detected more than 90 percent of asteroids large enough to cause a global catastrophe.
These include surveys that scan the sky from arrays of ground-based telescopes and spaceborne observatories which then catalogue NEOs, or predict the orbits they will search in.
Scientists can refine our ability to predict an asteroid’s chances of striking Earth — and give early warnings if a successful hit become more likely by continually updating what we know about the velocity at which it is moving.
In the case of 2001 WN5, continuous observations will be absolutely critical as we get closer to 2038.
Asteroid Redirection
Scientists have put forth various ways to divert an asteroid on a collision course with Earth.
One of the best strategies is a kinetic impactor, where you slam something into asteroid at high speed such that it shifts its orbit enough to guarantee Earth release.
This was proven feasible through NASA’s DART (Double Asteroid Redirection Test) mission that achieved the first-ever asteroid impact with the Dimorphous spacecraft in 2022.
Another possibility is a gravity tractor, or spacecraft that will fly near the asteroid and pull it slightly one way with its own minuscule gravity.
It would take decades, or perhaps centuries of very cautious observation as the changes in its flight path were so minute.
Closing: Valuing the Risks
As scary as a potential asteroid impact in 2038 may sound however, the probability of such thing happening is infinitesimally small.
Astronomers are keeping a close eye on 2001 WN5 and other NEOs, while substantial effort is being put into developing the technologies that might one day prevent such an impact from happening as well.
One silver lining is that there are people whose jobs require them to worry about these sorts of risks! This cosmic threat, currently so mysterious to us all will become more under our control due the experience we gain and also because of the increasing developments in tracking asteroids down.
2038 will no doubt be uneventful, but the continued surveillance and preparedness means we are nothing if not ready for whatever comes at us.