NASA will attempt to hit an asteroid later today. It is one of the most important things we have done in space, if not the most important thing, as this experiment will lead to a robust and effective planetary defense strategy for protecting life on Earth. We've landed humans on the Moon, transported rovers to Mars, and sent spaceships to other planets, but nothing compares to what might happen when DART crashes into Dimorphos, the smaller member of the Didymos asteroid system. The DART will hit the asteroid at 7:14 p.m. You can change the rock's speed by watching it live here. A small adjustment for an asteroid, but a huge leap for humankind. NASA's DART mission won't mean that we suddenly have a defense against threatening asteroids, but it will show a viable strategy for steering dangerous asteroids away from Earth. It will take many more years for our competency in this area to mature, but it all starts with DART.
DART is one of the most important missions in space history, according to Lindley Johnson, manager of NASA's Near-Earth Object Observations program. I concur. The missions to the Moon, Mars, and Pluto are important and monumental in their own right, but this proof-of-concept experiment could lead to defensive measures against an existential threat. It's very important.
The asteroid was between 10 and 9 miles wide and traveled around 12 km/s when it hit Mexico. All animals larger than a cat were wiped out in the crash. The reign of non-avian dinosaurs came to an end.
Our planet is not immune from asteroids of that size, even though they are rare. Between 16 and 32 asteroids larger than 3 miles are estimated to strike Earth every billion years. It takes about 30 million to 65 million years for that to happen. Impacts with asteroids larger than 10 km are very rare.
It is the kind of event that would wipe out our civilization. Developing the means to defend ourselves is a smart idea, but the threat of huge asteroids isn't what keeps me up at night.
According to the Southwest Research Institute, our atmosphere shreds most incoming asteroids. If objects smaller than 1 km in size reach the surface, they can cause a lot of damage at local scales, such as wiping out an entire city. According to Johnson, asteroids the size of Dimorphos strike Earth about once every 1000 years. A million asteroids are in the solar system, which is more than the width of a football field. There are an estimated 2,000 near- Earth objects. Severe environmental damage will be caused on a global scale if asteroids are hit. Mass extinctions can be caused by hitting asteroids larger than 6 miles.
If an asteroid is 100 to 165 feet (30 to 50 meters) in diameter or larger, it is considered to be potentially hazardous by NASA. The Center for Near Earth Object Studies keeps track of all known Near Earth objects to assess potential impact risks, and the space agency uses ground and space-based telescopes to detect and track these objects.
There are no known threats to Earth in the next 100 years. Astronomers find around 3000 NEOs each year. There is a chance that a newly detected asteroid is going to collide with Earth. In Hollywood films, we typically have only a few days or months to react to a scenario like this. He said we would have a few years or decades to respond.
Johnson pointed to two ways to protect our planet. The asteroid-hunting spacecraft is expected to launch in 2026 and will help with detection. DART is the first of many attempts to create a planetary shield.
DART is a test of a kinetic impactor, but scientists could develop a host of other strategies, such as using gravity tractors or nuclear devices, which could be surprisingly effective. Factors such as the asteroid's size and density will affect the type of technique used. There are so-called rubble pile asteroids which feature loose conglomerations of surface material. We won't know if Dimorphos is a rubble pile until DART hits it. Planetary defense is applied planetary science.
A case can be made that space experiments are more important than asteroids. We don't have the ability to live anywhere other than Earth, which limits our ability to save ourselves from emerging risks, such as run-away global warming, artificial malign superintelligence, or quantum computing.
It is important that we strive to become a multi-planet species and not have all our eggs in one basket, but that is going to take a long time for us to realize. We need to be prepared to meet that kind of threat and develop our ability to live off-planet.
The DART experiment introduces us to solar system re-engineering. Our civilization is poised to engage in more impactful interventions as we re-architect our surroundings to make it safer or find better ways of exploiting all that our solar system has to offer. Changing the Sun to make it last longer is one of the more meaningful interventions.
I am getting a little ahead of myself. DART will succeed in hitting its target later today.
All Rights Reserved © 2024
