Planetary defense is an effort to monitor and protect Earth from asteroids, comets, and other objects in space. earthly gravity pulls more than a hundred tons (more than 90 metric tons) of small objects and dust from space every day, NASA reports. Most of this material burns in the atmosphere without affecting the planet; larger pieces can produce a bright streak of light that can be seen on it. night skyor small meteorite, that a stone hunter can find.

earth atmospherethick and protective compared to more exposed surfaces Mercury or months, this reduces the danger of minor collisions. But life on Earth had previously been significantly altered by asteroid collisions; crater Chicxulubfor example, it is evidence of a spectacular planetary influence that led to the extinction of non-avian dinosaurs. Planetary defense systems work to detect potentially dangerous objects (in PHO, Planetary Defense Coordination Office terminology). NASA) close to Earth. While these systems have yet to detect or deal with serious threats, NASA, the European Space Agency (ESA) and other organizations are poised to one day redirect or destroy dangerous objects.

Today, telescopes around the world regularly scan the sky to determine the position of any object at risk of hitting our planet. directories like this Center for the study of near-Earth objects NASA (CNEOS) includes a list of threat levels and other data regarding these objects so that a warning is issued before any known object collides with the planet. Meanwhile, researchers are developing ways to physically change the course of PHOs and protect the planet from devastating collisions.

PLANET PROTECTION FREQUENTLY ASKED QUESTIONS ANSWERED BY AN EXPERT

We asked David Farnocchia, a navigation engineer at NASA’s Jet Propulsion Laboratory (JPL) and a scientist at the Center for Near-Earth Objects Research, some common questions about protecting the planet. Davide Farnocchia is a navigation engineer at NASA’s Jet Propulsion Laboratory (JPL) and a scientist at the JPL-led Near-Earth Object Study Center for NASA’s Planetary Defense Coordination Office.

How do we know if something like asteroids or comets is on a collision course with Earth?

Exploring as many asteroids and comets as possible as early as possible and predicting where they are headed. Fortunately, the movement of asteroids and comets is highly predictable, and we can tell years in advance whether one will hit Earth. But first we have to detect these objects and then follow them. That’s why NASA funds large telescopes to scan the night sky and discover as many asteroids and comets as possible.

When an object is detected, we use tracking measurements to estimate its orbit around the Sun. For most objects, the orbit doesn’t come close to Earth’s orbit, and we can eliminate any collisions right away. But some of these objects, called “near-Earth objects” (NEOs), are moving in orbits that could potentially bring them into the terrestrial region of the Solar System, and these objects require further analysis. That’s why we watch near-Earth objects closely and accurately plot their future trajectories to assess whether they can actually come close to Earth and possibly even collide. As we gain more data, we refine orbital calculations until we can definitively eliminate (or rule out) a collision with Earth.

What size asteroid will destroy Earth?

No near-Earth object is large enough to potentially “destroy” Earth. There are no asteroids or comets large enough for this approaching our planet. However, “What size asteroid would cause a global catastrophe?” you may ask.

1 kilometer asteroids [0,62 милі] or more could cause a global catastrophe if it hits the Earth. That’s why in 1998 the US Congress tasked NASA with detecting and tracking more than 90% of near-Earth objects larger than 1 km. This first mission was accomplished more than 10 years ago, and NASA has concluded that none of these massive objects discovered pose a threat of collision in the next century.

Could a comet crash into the Earth?

While no known comets pose a collision threat for the foreseeable future, comet collisions are possible, albeit extremely rare. Comets are much smaller than asteroids, and their orbits bring them much less close to Earth. Thus, comets represent about 1% of the total collision risk.

What factors affect whether an object is considered a threat to Earth?

The two main factors are the object’s trajectory and size. If the orbit of the object has no chance of passing the Earth, then this is not a threat. If the path of the object is possibly affected, we need to consider its size. Small impactors of a few meters or less in size will disintegrate in the atmosphere and will not cause any damage to the ground. Objects tens of meters in size can cause local damage, regional damage of 100 meters or more, and global damage of 1 km or more. The good news is that the expected frequency of collisions with Earth drops significantly for larger objects. For example, objects larger than 1 km collide with the Earth on average every few hundred thousand years. Collision events such as the 2013 Chelyabinsk meteor, which was only 20 m in size,

WHAT IS THE CURRENT DEFENSE SYSTEM OF THE WORLD?

Much of the planet’s current protection system is focused on detecting potential hazards, not active protection. Many organizations, including NASA and its CNEOS, are involved in tracking and classifying near-Earth objects (NEOs). NASA’s Double Asteroid Redirection Test (DART) mission in 2022 was the first to test a practical NEO deflection method demonstrating the agency’s ability to target and send a spacecraft to collide with an object in space, thus changing his course. Source