Written by Moanes Hawass
Monday, July 29, 2024 09:00 AM
Have you ever imagined that a large asteroid the size of the Eiffel Tower potentially colliding with Earth? What would the consequences be? The thought of such an event is catastrophic. This scenario of a large asteroid impacting Earth may not merely be a hypothetical exercise. In the next five years, an asteroid the size of a cruise ship will come closer to us than a television satellite, flying just 20,000 miles away in a remarkable incident.
The space rock has been named 99942 Apophis, named after the Egyptian god of chaos and destruction when it was discovered in 2004. Initially, scientists were very concerned it might hit us, but subsequent models indicated it would simply drift back into space. However, other asteroids of this size exist within our solar system, and the challenge remains that we don’t know how many there are or their trajectories.
That is why the mission of “planetary defense is essential. “We plan to observe Apophis during its visit on Friday, April 13, 2029, and study how we could potentially mitigate another asteroid on a collision course,” said astronomer Dr. Greg Brown from the Royal Observatory Greenwich, in an interview with Metro.co.uk. “If a space rock of this size were to impact a populated area, the destruction would be catastrophic.”
“If it were to head toward London, we would be talking about the potential eradication of most of its population,” he elaborated. “The explosion would be massive,” he noted. “People near the impact site wouldn’t realize it had struck until it was too late. They would be instantly obliterated, buildings across the city would be decimated, and millions could die if astronomers failed to detect the event in time to facilitate an evacuation. The entire southeast of the UK would suffer significantly, and the dust cloud would be visible for many miles.”
“I would expect that large regions of Europe would be aware of the situation,” Dr. Brown said, comparing it to a massive volcanic eruption which could lead to flight cancellations. Fortunately, the majority of the world is not densely populated – thus, even if an asteroid were to impact, it is unlikely to result in extreme suffering levels.
Dr. Brown highlights that two-thirds of the Earth’s surface is covered in water, and indeed, “the vast majority” of the planet is sparsely populated: “Therefore, the chances of an asteroid the size of Apophis hitting and causing a significant number of deaths are remarkably low.”
Nonetheless, this risk persists, which is why organizations like the NASA and the European Space Agency are engaged in planetary defense missions to investigate the composition and behavior of asteroids. Even if the odds are slim, the potential repercussions make it vital to be prepared for the worst-case scenario.
The threat an asteroid poses is directly related to its size; larger asteroids can be catastrophic to humanity, while smaller asteroids typically burn up in the atmosphere.
The most famous asteroid event that impacted Earth didn’t just cause the extinction of dinosaurs; the asteroid, measuring at least 10 kilometers wide, is believed to have released an immense amount of dust that blocked sunlight, leading to the demise of plant life and consequently the herbivores that depended on them.
Although a smaller asteroid like Apophis wouldn’t result in global climate shifts, it could have local effects on agriculture and light levels, potentially instigating a significant crisis. However, the positive news is that scientists believe they have identified all the “planet killers” in the vicinity that could induce a mass extinction event, and none exhibit signs of approaching Earth.
What is the lowest quality?
“We acknowledge that we are overlooking a substantial number of intermediate-sized asteroids,” Dr. Brown explains, referring to those measuring up to approximately 400 meters in diameter. “The count we currently have is much lower than we would expect.”
This can be assessed by examining the quantity of large asteroids readily visible in space, compared to smaller ones that come into our vicinity in the form of meteors and meteorites. The European Space Agency warned last year: “Numerous asteroids remain concealed in the light of our Sun, following unknown trajectories, many of which may be heading toward Earth, and we are unaware of their presence.”
Recently, on June 29, an asteroid approximately 150 meters in length passed closer to Earth than the Moon, at about 295,000 kilometers from our planet. Dubbed 2024 MK, we only discovered it 13 days earlier, on June 13.
Advancements in technology, including artificial intelligence, will likely aid us in mapping asteroids in our vicinity, but currently, there remains an element of uncertainty. In 2013, the Chelyabinsk asteroid appeared unexpectedly, exploding and disintegrating in the atmosphere before reaching the ground over the Ural Mountains in Russia.
Apophis is roughly 375 meters wide (compared to the Eiffel Tower, which stands at 300 meters tall), making it about 17 times larger and at the upper end of the mid-sized range. An impact from something of this size would release a blast “much greater” than that of Chelyabinsk and would be “absolutely devastating” to the surrounding area, Dr. Brown noted.
Most asteroids, ancient celestial bodies in orbit around the Sun, are primarily found in a belt between Mars and Jupiter. However, it is believed there are over 35,000 near-Earth objects, most of which are asteroids, that could potentially come our way.
Surprisingly (and reassuringly), even if an asteroid the size of the Eiffel Tower were to strike Earth, you would likely be unharmed. If it hit the ocean on the opposite side of the world, you might not even notice, aside from the subsequent news reports, Dr. Brown mentioned.
Residents on the Pacific Rim may be at risk of a tsunami, with potential global disruption due to our interconnected world. However, people in the UK would continue their daily lives, and even if it did strike land, provided it were in a rural area, the ensuing consequences would not be catastrophic, likened to nuclear tests conducted in deserts.
When Apophis approaches, it will be visible to the naked eye as a bright point, resembling a star moving across the sky. Simulation models indicate it will return for another pass in 2036 and 2068, but there’s no collision threat for at least the next century. The limited timeframe is not due to likelihood of an impact a hundred years from now, but because predictive simulations become less reliable the further we project into the future.
Its next close approach at 31,860 kilometers from Earth will be an event predicted to occur only every 5,000 to 10,000 years, thus scientists are eager to make the most of the opportunity to study it.
NASA has demonstrated the feasibility of altering an asteroid’s orbit by intentionally crashing into the 170-meter-wide asteroid Dimorphos at 14,000 mph in 2022. The space agency plans to send a spacecraft to Apophis as well, though this mission will not aim to change its course. It will form part of the Operation Osiris-Apex project (an update to the Osiris-Rex mission, which returned samples from Asteroid Bennu).
Written by Moanes Hawass
Monday, July 29, 2024 09:00 AM
The Fascinating Reality of Asteroids: What If One Hits Earth?
Have you ever imagined that a large asteroid the size of the Eiffel Tower could hit Earth? The consequences of such an event could be catastrophic. This isn’t just a thought exercise; in five years, an asteroid the size of a cruise ship will pass closer to us than a television satellite, flying just 20,000 miles away in a spectacular astronomical event.
This space rock is known as 99942 Apophis. Its name is derived from the Egyptian god of chaos and destruction, reflecting initial fears of a possible collision when it was discovered in 2004. Thankfully, models eventually showed Apophis would just swing back into space, but it does raise concerns about other asteroids this size that we are still unaware of.
Understanding Asteroid Impact Risks
This concern is precisely why the mission of planetary defense is crucial. “We are planning to fly alongside Apophis when it visits us on Friday, April 13, 2029, and study how we might be able to fend off another asteroid if it comes on a collision course,” said Dr. Greg Brown from the Royal Observatory Greenwich.
“If a space rock of this size were to hit a populated area,” he warns, “it would cause catastrophic damage.” For example, if it were to strike London, it could potentially wipe out most of the population in that region. The immediate impact would result in mass casualties, destruction of buildings, and long-term environmental issues.
Potential Effects of an Asteroid Impact
- Mass Casualties: A large asteroid impact could lead to millions of deaths, particularly if it hits a densely populated area.
- Destruction of Infrastructure: The explosion and subsequent shockwave would obliterate buildings and essential services.
- Environmental Changes: While Apophis may not cause global climate changes like the asteroid that wiped out the dinosaurs, it could still affect localized weather patterns and agriculture.
- Tsunami Risks: If an asteroid were to hit the ocean, regions along the Pacific Rim could face devastating tsunamis.
Fortunately, Dr. Brown reassures that the majority of Earth is not densely populated, and two-thirds of its surface is water. Therefore, while the potential effects of an asteroid impact are severe, the likelihood of significant casualties is relatively low.
Tracking and Identifying Potential Threats
Despite innovations in tracking, scientists are aware of a significant gap in our knowledge regarding intermediate-sized asteroids, those up to about 400 meters in diameter. Dr. Brown notes, “The number we know of is much lower than we think it should be.” This could be attributed to many asteroids lurking near the glare of the sun on unknown trajectories.
Just recently, on June 29, an asteroid about 150 meters long flew closer to Earth than the Moon. Discovered only 13 days prior, this highlights the urgency of advancing our detection technology. Such breakthroughs, including artificial intelligence, are expected to enhance our capabilities to map nearby asteroids.
Analyzing Apophis
Measuring approximately 375 meters wide, Apophis is significantly larger than most known asteroids. The comparisons are stark; it boasts a size around 17 times that of the Eiffel Tower, and should it collide, the result would be a blast much larger than the infamous Chelyabinsk event.
Current estimates suggest that there are over 35,000 near-Earth objects, many being asteroids, that could pose a threat. However, scientists believe they have tracked all major “planet killers” capable of causing mass extinction events, and none are currently on a collision course with Earth.
Comparative Impact Analysis
| Asteroid Size | Description | Potential Impact |
|---|---|---|
| Small (up to 25m) | Burns up in the atmosphere | No significant impact |
| Medium (25m – 400m) | Affects localized regions | Damage to agriculture, infrastructure |
| Large (>400m) | Massive explosion and environmental changes | Catastrophic regional or global effects |
To put it simply, while a close encounter with an asteroid can be alarming, scientists emphasize that the world is better equipped today for tracking these celestial bodies. While Apophis’ next encounter will be widely observed and studied, it is essential to remember that a significant asteroid impact remains a low probability event.
The Future: Preparing for Potential Impacts
Should an asteroid pose a threat, NASA has demonstrated that altering the orbit of a celestial body is feasible. The DART mission, which crashed a spacecraft into the asteroid Dimorphos at a speed of 14,000 mph in 2022, proved this capability. Future missions plan to study Apophis through Operation Osiris-Apex, further exploring potential deflection techniques should it become necessary.
The next rendezvous with Apophis in 2029 will provide invaluable data for planetary defense initiatives and may help safeguard our planet against future asteroid threats. Understanding and preparing for asteroid impacts is not merely a scientific curiosity but a critical aspect of ensuring our planet’s safety and security.