“Don’t Look Up”: Can a 10 km Meteor Destroy Earth? (and other science questions about the Netflix movie)

Attention: This article contains plot details for the Netflix movie Don´t Look Up.

Don’t Look Up shows us a scenario that has already been dealt with several times in the cinema, but this time it is done with satire and giving special relevance to science and scientists.

The film shows two astronomers, starring Leonardo Di Caprio y Jennifer Lawrence, who discover that a comet is imminently heading for Earth and will destroy it completely.

The film, directed by Adam McKay, explores the role of the media, politics, social networks and science itself regarding the reaction that humanity would have in front of an event like that.

At BBC Mundo we review some of the scientific aspects that are addressed in the plot.

What are comets? What is the difference between comets, asteroids, meteors, meteoroids, and meteorites?

Comets are primitive objects in the Solar System, formed about 4.6 billion years ago, according to the European Space Agency.

Its name comes from the Greek comet, which means “long hair”, due to the striking light tail that characterizes them.

Comets are made mostly of ice, which partly evaporates when they pass close to the Sun.

The comet’s tail, meanwhile, is made of dust and gas, which are released when the Sun evaporates the comet’s surface.

There are millions of comets, located in distant and cold regions of the Solar System, such as the Kuiper belt, a ring of icy bodies located outside the orbit of Neptune.

Asteroids, on the other hand, are objects made of rock and not ice, like comets. They are smaller than a planet, but larger than a meteoroid.

Most of the asteroids in the Solar System are located in the Asteroid Belt, between Mars and Jupiter.

When one asteroid or comet collides with another, both bodies fragment into smaller pieces called meteoroids.

When a meteoroid enters Earth’s atmosphere, it becomes a meteor.

Meteors are the stars of the dazzling “meteor showers”, and although they are not stars, meteors are popularly called “shooting stars”.

The beam of light from meteors can sometimes be mistaken for comets.

Finally, meteorites are meteors that manage to pass through the Earth’s atmosphere and fall like rocks on the surface of our planet.

How likely is a meteor to hit Earth?

According to NASA, about a hundred tons of interplanetary material fall on Earth every day. Most of that material is dust that is released from comets.

The United Nations Office for Outer Space Affairs (UNOOSA) defines a category of space bodies called Near-Earth Objects (NEO).

An asteroid or comet is considered a NEO when it is about 50 million kilometers from Earth’s orbit.

For reference, the Moon is 384,400 km from Earth.

As of December 17, 2021, NASA has recorded nearly 28,000 NEOS since 1980. Of these, 117 are comets and the rest are asteroids.

Among them, 2,238 were classified as “Potentially Dangerous Asteroids”, as they passed within 4.7 million km of Earth’s orbit and were greater than 140 meters in size.

But also, on an average of every 10,000 years there is the possibility that asteroids greater than 100 meters can impact on the Earth and cause local disasters or generate waves that flood coastal areas.

NASA also estimates that every “several hundred thousand years,” an asteroid larger than one kilometer could hit Earth.

If that happens, the debris would spread through the atmosphere. They would cause acid rain, sunlight would be partially blocked, and rocks would again fall into flames on Earth.

It is estimated that the meteorite that caused the extinction of the dinosaurs 65 million years ago was between 10 km and 15 km wide.

NASA states that “no known asteroid poses a significant risk of impact with Earth for the next 100 years.”

The highest risk is represented by an asteroid called 2009 FD, which in the year 2185 will have less than 0.2% chance of impacting the planet.

Are there protocols and defense mechanisms against meteorites that can threaten the Earth?

Both ESA and NASA have planetary defense offices dedicated to monitoring NEOS.

The mission of these offices is to identify and track the trajectory of objects that may represent a risk to the Earth, define their characteristics, evaluate the consequences of a possible impact, share the information with other agencies and develop methods to deflect asteroids.

In November, NASA and ESA launched the first mission to deflect an asteroid.

It is about the DART ship that has the objective of crashing with the asteroid Dimorphos and changing its course.

This asteroid poses no risk to Earth, but the idea is to test the technology that might one day be necessary to deflect a dangerous asteroid from its course.

Among the methods NASA sees as most viable is deflecting the asteroid’s path, either by the force of gravity from another object or by hitting the asteroid, as DART will. He also mentions that using nuclear explosives should be “the last resort.”

Can you extract wealth from meteorites?

Asteroids that pass close to Earth have the potential to one day be exploited for raw materials, NASA says.

Asteroids can contain metals like iron, nickel, platinum, and gold, which can be used to generate rocket fuel and build structures in space.

According to NASA, it is estimated that the accumulated mineral wealth in the Asteroid Belt would be equivalent to about $ 100 billion for each person on Earth.

In 2020, a study calculated that the asteroid Psyche 16, discovered in 1852, contains an amount of metals equivalent to US $ 10,000 quadrillion.

Taking into account that the value of the global economy in 2019 was US $ 142 trillion according to the German data portal Statista, it could be said that Psyche minerals are worth about 70,000 times more.

In 2022, NASA and SpaceX plan to launch a spacecraft that should reach Psyche 16 in 2026.