There is a dangerous environment on the Earth. asteroids and comets crash into our planet as they zoom through space. Most of these are too small to pose a threat, but some can be cause for concern.
As a scholar who studies space and international security, it is my job to ask what the likelihood of an object crashing into the planet really is, and whether governments are spending enough money to prevent such an event.
One needs to know what near-Earth objects are out there to find the answers to these questions. NASA has only been able to track 40% of the bigger ones. Surprise asteroids have visited Earth in the past and will do so in the future. How prepared will humanity be when they show up?
There are millions of objects on the Sun. asteroids and comets that are within 120 million miles of the Sun are near-Earth objects.
Astronomers consider a near-Earth object to be a threat if it comes within 7 million km of the planet and is at least 480 feet in diameter. If a body of this size crashes into Earth, it could cause a lot of damage. Larger objects could have global effects and even cause mass extinctions.
65 million years ago, a large asteroid crashed into the Yucatn Peninsula, causing a lot of damage. Dinosaurs were wiped out along with most plant and animal species.
Smaller objects can cause damage. A body of water in Siberia exploded in 1908. It leveled more than 80 million trees. An asteroid exploded in the sky above Chelyabinsk, Russia, in 2013. It injured over 1,100 people and caused US$33 million in damage by releasing the equivalent of 30 Hiroshima bombs.
2005 ED224 is the next large asteroid that could hit Earth. There is a 1 in 500,000 chance of an impact when the asteroid passes by on March 11, 2023.
The chances of a large body hitting Earth are small, but the damage would be enormous.
The 1998 Spaceguard Survey mandated NASA to find and track 90 percent of near-Earth objects within 10 years. In 2011, NASA surpassed the goal.
Congress passed a bill in 2005 that requires NASA to find at least 90% of all near-Earth objects by the end of 2020. Due to a lack of financial resources, only 40% of the objects have been mapped.
Astronomers have found 28,266 near-Earth asteroids, of which 10,033 are larger in diameter and at least 1 km across. Each week there are about 30 new objects added.
A new mission, funded by Congress in 2018, is scheduled to launch in 2026 and is dedicated to searching for potentially dangerous asteroids.
asteroids have sneaked up on Earth before and we can only prevent a disaster if we know it is coming.
An asteroid the size of a football field passed by Earth in 2019. An asteroid the size of a jumbo jet came close to Earth in 2021. They were discovered a day before they passed Earth.
Some research suggests that the Earth's rotation may cause some asteroids to remain undetected. Some asteroids do not miss us, so this may be a problem. Astronomers spotted a small asteroid 19 hours before it crashed into Sudan. The recent discovery of an asteroid 1.2 miles in diameter suggests that there are still big objects out there.
Early detection is important to protect the planet. Scientists at the Planetary Defense Conference recommended a minimum of five to 10 years to prepare for a successful defense against asteroids.
There are four ways to mitigate a disaster if an astronomer finds a dangerous object. The first involves first-aid and evacuate measures. A second approach would involve sending a craft to fly near the asteroid and then changing the object's position. We can either crash something into the asteroid at high speeds or blow it up.
NASA launched the world's first full-scale planetary defense mission as a proof of concept in November 2021. Didymos and its small moon are not a threat to Earth. NASA plans to crash a 1,340-pound probe into the Didymos moon in September of 2022.
Learning more about the composition of threatening asteroids is important, as it may affect how successful we are at defusing them. The asteroid Bennu has a diameter of 490 meters. There is a 1 in 2,700 chance that it will collide with Earth. NASA launched the OSIRIS-Rex probe in 2016 to learn more about Bennu, an asteroid that could wipe out an entire continent. After arriving at Bennu, the spacecraft collected samples and will return to Earth in three years.
NASA's planetary defense budget was more than $150 million in 2011. NASA's total budget is just 0.7% of the US defense budget.
The budget supports a number of missions, including the DART at $324 million and Osiris Rex at $1 billion over several years.
Is this the right amount of money to invest in keeping an eye on the skies, given the fact that some 60% of all potentially dangerous asteroids remain undetected? When considering the potential consequences, this is an important question to ask.
Buying homeowners insurance is similar to investing in planetary defense. People buy insurance even though they don't know if the house will be destroyed.
The destruction and loss of life would be extreme if a single object larger than 140 meters hit the planet. Most species on Earth could be wiped out by a bigger impact. The chance of a body hitting Earth in the next 100 years is not zero. Investing in protecting the planet from dangerous objects may give humanity some peace of mind and could prevent a catastrophe.
Svetla Ben-Itzhak is an assistant professor of space and international relations at Air War College. The original article is worth a read.
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