One of the big stories of the week was the discovery of another asteroid which could crash into the Earth in future, causing enormous damage.
Fortunately in this context, 2024 YR4, the newcomer, is believed to be only 40 to 100 metres (130-330 ft) across. If it should in fact strike the planet – there is a small chance of this happening a few days before Christmas in 2032 – the amount of energy released will be no more than, say, 150 megatons, around the same as a relatively limited nuclear bombardment but without the radiation.
This is described by the US National Research Council as a “local” to “regional” scale event. If the asteroid were to strike in the middle of the ocean or a wilderness, there might not be too much of a problem. If things went badly it might destroy a city, or in the worst case a nation or two might be wrecked. But human civilisation would survive.
Better still, defence against asteroids of this size is known to be feasible. In 2022, Nasa carried out a mission known as the Double Asteroid Redirection Test, or Dart. In this, a spacecraft was deliberately crashed into the asteroid Dimorphos, which is bigger than 2024 YR4, successfully altering its orbit. Had Dimorphos been headed for Earth – it was not – it would have been diverted so as to miss.
In the event that 2024 YR4 is found to be on course to strike Earth, it’s clear that a similar mission could be sent out to ward it off. It’s thought that impacts in this class take place every few thousand years, so even if 2024 YR4 misses us as it probably will, we’ll need to defend ourselves sooner or later. It’s reassuring to think that for the first time in human history, we are not helpless in the face of such events.
But things would be very different in the case of a much larger asteroid, one more than a kilometre (over half a mile) across.
If such a monster were to strike Earth, the energy release would be more than 100,000 megatons – worse than an all-out, global nuclear war. Human civilisation would be likely to collapse, and if the asteroid were big enough the human race, and much of the rest of life on Earth, would face extinction. Many scientists believe that it was an impact in this class which ended the age of the dinosaurs.
It would not be possible to build and launch a Dart-type spacecraft heavy and fast enough to significantly affect the course of such a massive asteroid. The only possible means of delivering enough energy to deflect the destroyer would be the use of a nuclear weapon.
One of the big stories of the week was the discovery of another asteroid which could crash into the Earth in future, causing enormous damage.
Fortunately in this context, 2024 YR4, the newcomer, is believed to be only 40 to 100 metres (130-330 ft) across. If it should in fact strike the planet – there is a small chance of this happening a few days before Christmas in 2032 – the amount of energy released will be no more than, say, 150 megatons, around the same as a relatively limited nuclear bombardment but without the radiation.
This is described by the US National Research Council as a “local” to “regional” scale event. If the asteroid were to strike in the middle of the ocean or a wilderness, there might not be too much of a problem. If things went badly it might destroy a city, or in the worst case a nation or two might be wrecked. But human civilisation would survive.
Better still, defence against asteroids of this size is known to be feasible. In 2022, Nasa carried out a mission known as the Double Asteroid Redirection Test, or Dart. In this, a spacecraft was deliberately crashed into the asteroid Dimorphos, which is bigger than 2024 YR4, successfully altering its orbit. Had Dimorphos been headed for Earth – it was not – it would have been diverted so as to miss.
In the event that 2024 YR4 is found to be on course to strike Earth, it’s clear that a similar mission could be sent out to ward it off. It’s thought that impacts in this class take place every few thousand years, so even if 2024 YR4 misses us as it probably will, we’ll need to defend ourselves sooner or later. It’s reassuring to think that for the first time in human history, we are not helpless in the face of such events.
But things would be very different in the case of a much larger asteroid, one more than a kilometre (over half a mile) across.
If such a monster were to strike Earth, the energy release would be more than 100,000 megatons – worse than an all-out, global nuclear war. Human civilisation would be likely to collapse, and if the asteroid were big enough the human race, and much of the rest of life on Earth, would face extinction. Many scientists believe that it was an impact in this class which ended the age of the dinosaurs.
It would not be possible to build and launch a Dart-type spacecraft heavy and fast enough to significantly affect the course of such a massive asteroid. The only possible means of delivering enough energy to deflect the destroyer would be the use of a nuclear weapon.