According to Indian scientists, NASA's mission to deflect an asteroid is a step toward preparing the world for a potential future asteroid strike similar to the one that wiped out the dinosaurs 66 million years ago, although the likelihood of such an event occurring in our lifetime is extremely remote.
In a first-of-its-kind mission, the Double Asteroid Redirection Test (DART) spacecraft successfully collided with an asteroid on Tuesday to determine if future asteroids that could pose a threat to Earth could be deflected away.
DART, the world's first demonstration of planetary defense technology, targeted the 160-meter-diameter asteroid moonlet Dimorphos.
Our planet is surrounded by asteroids and comets that orbit the Sun. Very few are potentially hazardous to the planet. According to Chrisphin Karthick, a scientist at the Indian Institute of Astrophysics (IIA), Bengaluru, "it is best to prepare our defenses to avoid such asteroids on a collision course with Earth in the future."
Karthick, who is involved with the DART project, stated that the mission is "certainly a step towards" preparing the world for a potential future event similar to the one believed to have caused the extinction of dinosaurs 66 million years ago.
This successful DART mission exemplifies this point. We now know how to precisely aim the spacecraft at a body of this size. The post-impact observations of this DART mission can also help us prepare for the larger body, Karthick told PTI.
Didymos is a larger, 780-meter-wide asteroid that Dimorphos orbits. Both asteroids pose no danger to Earth. Comparatively, the dinosaur-killing asteroid was approximately 10 kilometers in diameter.
NASA has confirmed that the DART mission's one-way journey can successfully navigate a spacecraft to kinetically impact an asteroid in order to deflect it.
Goutam Chattopadhyay, a senior scientist at NASA's Jet Propulsion Laboratory (JPL) in the United States, remarked that the mission will assist in preparation for a future asteroid threat.
"DART is an experimental mission to test a concept for asteroid deflection. If we can encounter these asteroids whose track is towards us at a sufficient distance from Earth, then a minor deflection will be sufficient to alter the asteroid's path, he explained.
However, scientists emphasized that the vast majority of asteroids of a size that could inflict damage to Earth had a negligible chance of colliding with the planet.
"However, the chance is not zero, and we must remain watchful at all times. There is always a chance that a major storm could be headed our way, therefore the question becomes what our strategy would be and how we could limit the risk. "Therefore, these programs are essential," Chattopadhyay told PTI.
"At least for the next century, there is no mass-casualty-causing threat from known asteroids," said Karthick, noting that this risk assessment is based on the asteroids now known to science.
Small asteroids continually collide with the Earth, but they are destroyed by the atmosphere's heat. However, this is not the case for sufficiently big asteroids, as the outer core will burn but enough mass will remain to do damage.
Using ground-based telescopes, the team will now examine Dimorphos to establish that DART's collision affected the asteroid's orbit around Didymos.
Researchers anticipate that the collision will decrease Dimorphos' orbit by around 1 percent, or roughly 10 minutes; one of the key goals of the full-scale test is to exactly measure how much the asteroid was deflected.
"After impact, the team will use ground-based telescopes to examine Dimorphos in order to prove that DART's impact affected the asteroid's orbit around Didymos," Karthick explained.
"The projected result of the impact is a 1% reduction in Dimorphos' orbital period, or around 10 minutes. "One of the key objectives is to measure the orbital deviation of the asteroid," he continued.
However, Chattopadhyay stated that it will not be known whether the mission was able to alter the asteroid's orbit until all the data has been collected.
"I would want to emphasize that our calculations and lab studies on a modest scale indicate that it may work well," he added NASA employs a multifaceted strategy to monitor Near Earth Asteroids (NEAs). In 1998, the space agency launched an observational program. The majority of findings are supported by ground-based telescopic surveys. They are predominantly ground-based systems. Nevertheless, our existing space-based satellites are also utilized to scan and monitor these objects," the expert stated.
Lidar is a technique for detecting distance by directing a laser at an item or surface and measuring the time required for the reflected light.
"The DART mission is humanity's first effort to change an asteroid's trajectory by smashing an artificial object into it. Today's effective impact represents a significant advance in this direction.
Dibyendu Nandi, a space scientist at the Indian Institutes of Science Education and Research in Kolkata, stated, "However, to determine the ultimate effectiveness of this notion, we must wait a few more years till any meaningful change in the trajectory becomes evident."
