Latest news with #CatalinaSkySurvey
Indian Express
15-07-2025
- Science
- Indian Express
When the sky falls: Why and how we track dangerous asteroids
In 2013, a meteor exploded over the Russian city of Chelyabinsk with the force of 30 Hiroshima bombs. The blast injured over a thousand people and shattered windows across six cities. Yet the object—roughly 20 meters wide—had gone completely undetected. That event jolted the world into remembering: space isn't empty, and Earth isn't invincible. 'Had it arrived a few seconds later,' a Russian scientist remarked afterward, 'it would have struck Moscow.' A chilling reminder that even modest asteroids, if aimed wrong, could rewrite history. Astronomers today track thousands of asteroids not just out of scientific curiosity, but to guard our planet. Their mission: find potential threats early enough to act. Asteroids are the leftover building blocks of the solar system—chunks of rock and metal that never formed into planets. Most orbit peacefully in the asteroid belt between Mars and Jupiter. But gravity, collisions, and time conspire to kick some of them into paths that cross Earth's orbit. These are called Near-Earth Objects (NEOs), and while most are small and harmless, a few could do real damage. Some are city-sized. Others are merely car-sized. But speed matters. A rock the size of a bus moving at 30 km/s carries enough energy to level a town. The larger ones could devastate continents, or even end civilizations. In 1994, the solar system gave us a dramatic warning shot. The fragments of Comet Shoemaker–Levy 9 slammed into Jupiter with unimaginable force, carving enormous scars into the gas giant's atmosphere. If such an object had hit Earth, the results would have been catastrophic. Jupiter's gravity, in fact, helps shield us from some of these impacts—its massive pull captures or redirects many rogue bodies. But not all. The first step to stopping a disaster is seeing it coming. To know whether an asteroid will do a fly-by or crash into Earth, astronomers must determine its orbit with high precision. This is done by observing it from different locations on Earth—or at different times from the same telescope—and measuring how its position shifts against the background stars. Much like how our two eyes create depth perception, these small differences allow astronomers to triangulate the asteroid's distance and path through space. With a few accurate observations, they can plug the data into orbital equations and predict whether it poses a risk—often decades in advance. Around the world, telescopes like Pan-STARRS in Hawaii and the Catalina Sky Survey in Arizona scan the night sky for anything moving against the backdrop of stars. New software, using artificial intelligence and improved optics, flags any suspicious motion—possible asteroids. Once spotted, astronomers trace the object's orbit. Using a few data points and Newtonian physics, they can project its trajectory for decades into the future. If it looks like it might get too close, they raise the alarm. Still, we're far from complete coverage. NASA estimates we've found over 90% of the planet-killer-sized asteroids (>1 km), but only a fraction of smaller ones. Many space rocks—especially dark ones—can slip past unnoticed until they're right on top of us. Missions like the Vera Rubin Observatory, coming online soon, aim to plug that gap. If we discover an object on a collision course, our best defense is time. The more lead time we have, the smaller the nudge needed to shift an asteroid's path away from Earth. In 2022, NASA tested one such idea with the DART mission (Double Asteroid Redirection Test). The spacecraft crashed into a small asteroid moonlet, changing its orbit—a real-world demonstration that we can, in principle, deflect asteroids. Other proposals include using spacecraft as gravity tractors, lasers to vaporize surface material and push the asteroid off course, or even painting it white so that reflected sunlight slowly alters its orbit. But all of these require early detection—no last-minute Hollywood-style heroics. A sufficiently large asteroid impact could cause wildfires, tsunamis, earthquakes, and trigger a years-long 'impact winter' by throwing up enough dust to block sunlight. Crops would fail. Food chains would collapse. Mass extinctions are not theoretical—they've already happened. The asteroid that likely wiped out the dinosaurs 66 million years ago was about 10 km wide. It struck with the energy of 10 billion Hiroshima bombs, creating a crater over 150 km across and changing Earth's climate in a matter of hours. While such events are rare, smaller impacts—like the Tunguska explosion in Siberia (1908), which flattened over 2,000 square kilometers of forest—are far more frequent. Asteroids are not only harbingers of doom. They are also time capsules from the early solar system, preserving the chemical recipes that formed planets and possibly seeded life. Space agencies have launched sample-return missions like OSIRIS-REx and Hayabusa2, which brought asteroid dust back to Earth for analysis. Some of these rocks contain organic molecules and hints about Earth's early chemistry. Looking further ahead, some visionaries see asteroids as mining targets. Rich in metals like nickel, platinum, and cobalt, they could one day fuel in-space construction or provide rare resources without digging up Earth. India too is stepping up its asteroid-tracking efforts. ISRO has initiated sky-survey programs, and Indian astronomers contribute to global databases tracking thousands of NEOs. The country is also part of international planetary defense discussions. Meanwhile, space agencies around the world—NASA, ESA, JAXA—are building partnerships to share data and improve global readiness. Because when it comes to planetary defense, the whole world is on the same team. The cosmos doesn't just whisper in radio signals or twinkle with light—it throws rocks. And we're finally watching. For the first time in history, we have the means to detect and potentially deflect incoming threats. It's a rare moment where foresight, physics, and global cooperation might actually save the world—not in theory, but in practice. Shravan Hanasoge is an astrophysicist at the Tata Institute of Fundamental Research.
Yahoo
06-06-2025
- Science
- Yahoo
Watch an asteroid the size of an aircraft carrier make a close pass of Earth on June 5
When you buy through links on our articles, Future and its syndication partners may earn a commission. A potentially hazardous asteroid roughly the size of an aircraft carrier is due to pass within 2.8 million miles (3.5 million km) of Earth on June 5 and you can watch it happen live online. NASA and its partners have been tracking the potentially hazardous asteroid 2008 DG5 ever since its discovery in (you guessed it) 2008 by the Catalina Sky Survey. The Center for Near Earth Object Studies (CNEOS) estimates it to have a diameter ranging between 1,049-2,296 ft (320-700 meters) - roughly the equivalent of the length of a Gerald R. Ford-class aircraft carrier. The asteroid will make its closest approach to Earth at 7.59 p.m. ET (2359 GMT) on June 5, at which time it will pass 2,170,309 miles (3,492,787 kilometers) from our planet, over nine times the Earth-moon average orbital distance. At this range 2008 DG5 will be visible as a solitary point of light to powerful Earthbound telescopes. The Virtual Telescope Project will host a livestream of the flyby starting at 6 p.m. ET (2200 GMT) on June 5, featuring real-time views of 2008 DG5 captured by its suite of robotic telescopes. June 3 saw the project release an image of the asteroid captured from a distance of 2.2 million miles (3.6 million km) using the 17-inch PlaneWave telescope located in Manciano, Italy, as the asteroid cruised closer to Earth. 2008 DG5 can be picked out as a bright speck of light, with short star lines acting as a tell-tale sign of its movement against the static starfield beyond, created as the telescope tracked its position over a 120-second exposure. NASA classifies an asteroid as potentially hazardous based on a number of factors including its size and whether it will pass within 0.05 astronomical units of Earth - the equivalent of around 4,650,000 miles (7,480,000 km), according to the agency's Jet Propulsion Laboratory. Over 1,784 PHAs are being actively tracked by the CNEOS, none of which are predicted to strike Earth and cause widespread damage in the coming century.
Yahoo
24-02-2025
- Science
- Yahoo
Earth safe from 'city-killer' asteroid 2024 YR4 'That's impact probability zero folks!'
When you buy through links on our articles, Future and its syndication partners may earn a commission. Time to breathe a sigh of relief. The asteroid that once posed the greatest impact risk to Earth in recorded history now has an effective 0% chance of striking our planet. The probability of asteroid 2024 YR4 hitting Earth was reduced to zero thanks to new data collected on Sunday, Feb. 23. Discovered in Dec. 2024, 2024 YR4 quickly climbed to the top of NASA's Sentry Risk table, at one point having a 1 in 32 chance of hitting Earth. This elevated it to Level 3 on the Torino scale, a system used since 1999 to categorize potential Earth impact events. Level 3, which falls within the yellow band of the Torino Scale, is described as: "A close encounter, meriting attention by astronomers. Current calculations give a 1% or greater chance of collision capable of localized destruction." "The NASA JPL Center for Near-Earth Object Studies (CNEOS) now lists the 2024 YR4 impact probability as 0.00005 (0.005%) or 1-in-20,000 for its passage by Earth in 2032," Richard Binzel, Professor of Planetary Science at the Massachusetts Institute of Technology (MIT) and creator of the Torino scale exclusively told "That's impact probability zero folks!" This conforms to the second part of the Torino scale level 3 description, which states: "Most likely, new telescopic observations will lead to re-assignment to Level 0. Attention by public and by public officials is merited if the encounter is less than a decade away.""Asteroid 2024 YR4 has now been reassigned to Torino Scale Level Zero, the level for 'No Hazard' as additional tracking of its orbital path has reduced its possibility of intersecting the Earth to below the 1-in-1000 threshold," Binzel continued. "1-in-1000 is the threshold established for downgrading to Level 0 for any object smaller than 100 meters; YR4 has an estimated size of 164 feet (50 meters)." As 2024 YR4 has continued to merit attention from news organizations across the globe, has been consulting with asteroid hunter David Rankin of the Catalina Sky Survey, who found images of the space rock in archival data that was gathered prior to its official discovery. From the outset, Rankin anticipated that 2024 YR4's impact odds would initially rise before dropping dramatically. He explained where this uncertainty originates when tracking an asteroid's trajectory. "Imagine holding a stick that is a few feet long. If you move the stick in your hand a fraction of an inch, you hardly notice any movement on the other end," Rankin said. "Now imagine that stick is many millions of miles long. Moving your hand a fraction of an inch will cause dramatic changes on the other end." That "fraction of an inch" movement is analogous to the tiny uncertainties in the positional measurements of the asteroid from the telescope's imaging the asteroid which arises from small timing errors and minor positional errors. As more observations are collected, these uncertainties begin to be eliminated. Though asteroid 2024 YR4 is likely to now drop from public attention, Binzel rounded up some of the points that we should all remember from the evolution of this story. "As 2024 YR4 fades away from the news cycle, I think there is an overall context that is the most important takeaway news," the MIT researcher said. "An object the size of YR4 passes harmlessly through the Earth-moon neighborhood as frequently as a few times per year. "The YR4 episode is just the beginning for astronomers gaining the capability to see these objects before they come calling through our neck of the woods." Binzel added that, as with 2024 YR4, some newly discovered asteroids will initially have uncertain miss distances, but follow-up observations will clarify their paths. "But, just like YR4, with a little time and patient tracking, we will be able to rule out entirely any hazard," he continued. "This means that objects with low categories on the Torino Scale are likely to be a common occurrence, of interest to space enthusiasts and astronomers for follow-up, but not particularly newsworthy." Related Stories: — Earth's mini-moon has finally departed. Will it ever return as a 'second moon?' — Asteroid the size of 3 million elephants zooms past Earth — Astronauts could mine asteroids for food someday, scientists say While 2024 YR4 poses no threat, it will still have a major scientific impact when it passes Earth in 2028 and again in 2032. On Dec. 17, the asteroid will come to within 5 million miles of Earth. Then, on Dec.22, 2032, 2024 YR4 will pass within just 167,000 miles of our planet. For context, the moon is 238,855 miles away. While the general public can sleep soundly knowing that 2024 YR4 won't hit Earth, unleashing city-wide devastation, scientists will relish the opportunity to study this space rock in detail."Rather than making anyone anxious, by finding these objects that are already out there and pinning down their orbits, we are becoming more secure in our knowledge that any sizable asteroid is not likely to take us by surprise," Binzel concluded.
Yahoo
24-02-2025
- Science
- Yahoo
Earth safe from 'city-killer' asteroid 2024 YR4 'That's impact probability zero folks!'
When you buy through links on our articles, Future and its syndication partners may earn a commission. Time to breathe a sigh of relief. The asteroid that once posed the greatest impact risk to Earth in recorded history now has an effective 0% chance of striking our planet. The probability of asteroid 2024 YR4 hitting Earth was reduced to zero thanks to new data collected on Sunday, Feb. 23. Discovered in Dec. 2024, 2024 YR4 quickly climbed to the top of NASA's Sentry Risk table, at one point having a 1 in 32 chance of hitting Earth. This elevated it to Level 3 on the Torino scale, a system used since 1999 to categorize potential Earth impact events. Level 3, which falls within the yellow band of the Torino Scale, is described as: "A close encounter, meriting attention by astronomers. Current calculations give a 1% or greater chance of collision capable of localized destruction." "The NASA JPL Center for Near-Earth Object Studies (CNEOS) now lists the 2024 YR4 impact probability as 0.00005 (0.005%) or 1-in-20,000 for its passage by Earth in 2032," Richard Binzel, Professor of Planetary Science at the Massachusetts Institute of Technology (MIT) and creator of the Torino scale exclusively told "That's impact probability zero folks!" This conforms to the second part of the Torino scale level 3 description, which states: "Most likely, new telescopic observations will lead to re-assignment to Level 0. Attention by public and by public officials is merited if the encounter is less than a decade away.""Asteroid 2024 YR4 has now been reassigned to Torino Scale Level Zero, the level for 'No Hazard' as additional tracking of its orbital path has reduced its possibility of intersecting the Earth to below the 1-in-1000 threshold," Binzel continued. "1-in-1000 is the threshold established for downgrading to Level 0 for any object smaller than 100 meters; YR4 has an estimated size of 164 feet (50 meters)." As 2024 YR4 has continued to merit attention from news organizations across the globe, has been consulting with asteroid hunter David Rankin of the Catalina Sky Survey, who found images of the space rock in archival data that was gathered prior to its official discovery. From the outset, Rankin anticipated that 2024 YR4's impact odds would initially rise before dropping dramatically. He explained where this uncertainty originates when tracking an asteroid's trajectory. "Imagine holding a stick that is a few feet long. If you move the stick in your hand a fraction of an inch, you hardly notice any movement on the other end," Rankin said. "Now imagine that stick is many millions of miles long. Moving your hand a fraction of an inch will cause dramatic changes on the other end." That "fraction of an inch" movement is analogous to the tiny uncertainties in the positional measurements of the asteroid from the telescope's imaging the asteroid which arises from small timing errors and minor positional errors. As more observations are collected, these uncertainties begin to be eliminated. Though asteroid 2024 YR4 is likely to now drop from public attention, Binzel rounded up some of the points that we should all remember from the evolution of this story. "As 2024 YR4 fades away from the news cycle, I think there is an overall context that is the most important takeaway news," the MIT researcher said. "An object the size of YR4 passes harmlessly through the Earth-moon neighborhood as frequently as a few times per year. "The YR4 episode is just the beginning for astronomers gaining the capability to see these objects before they come calling through our neck of the woods." Binzel added that, as with 2024 YR4, some newly discovered asteroids will initially have uncertain miss distances, but follow-up observations will clarify their paths. "But, just like YR4, with a little time and patient tracking, we will be able to rule out entirely any hazard," he continued. "This means that objects with low categories on the Torino Scale are likely to be a common occurrence, of interest to space enthusiasts and astronomers for follow-up, but not particularly newsworthy." Related Stories: — Earth's mini-moon has finally departed. Will it ever return as a 'second moon?' — Asteroid the size of 3 million elephants zooms past Earth — Astronauts could mine asteroids for food someday, scientists say While 2024 YR4 poses no threat, it will still have a major scientific impact when it passes Earth in 2028 and again in 2032. On Dec. 17, the asteroid will come to within 5 million miles of Earth. Then, on Dec.22, 2032, 2024 YR4 will pass within just 167,000 miles of our planet. For context, the moon is 238,855 miles away. While the general public can sleep soundly knowing that 2024 YR4 won't hit Earth, unleashing city-wide devastation, scientists will relish the opportunity to study this space rock in detail."Rather than making anyone anxious, by finding these objects that are already out there and pinning down their orbits, we are becoming more secure in our knowledge that any sizable asteroid is not likely to take us by surprise," Binzel concluded.
Yahoo
20-02-2025
- Science
- Yahoo
NASA lowers impact risk of 'city-killer' asteroid 2024 YR4 to 1 in 67 (phew!)
When you buy through links on our articles, Future and its syndication partners may earn a commission. If you've been worrying about reports of a possible asteroid impact in 2032, we have very good news! NASA has dropped the probability of an impact from asteroid 2024 YR4 to 1 in 67. NASA announced the reduced impact risk on its X feed at around 5:00 p.m. EST (2200 GMT) on Wednesday (Feb. 19). The updated assessment was based on new orbital data for the asteroid, which is estimated to be around 180 feet (55 meters) wide, collected overnight between the Feb. 18 and Feb. 19. The radical drop in impact risk for 2024 YR4 came just a day after its risk factor was increased to 1 in 32 or 3.1%. This increase saw 2024 YR4 become the most risky asteroid in the history of NASA's Center for Near Earth Object Studies (CNEOS) Sentry Risk Table was introduced. Despite the extreme drop in impact risk, 2024 YR4 still sits at the top of the Sentry table. The next riskiest asteroid on the table is 1950 DA, which has a 0.039% chance of impacting Earth in 2880. Regarding the drop in 2024 YR4's impact risk on Dec. 22, 2032, NASA wrote: "New observations of asteroid 2024 YR4 helped us update its chance of impact in 2032. The current probability is 1.5%. "Our understanding of the asteroid's path improves with every observation. We'll keep you posted." As NASA dropped the impact risk of 2024 YT4, the European Space Agency (ESA) also reduced the asteroid's risk of impacting Earth in 2032 to 1.38% or around 1 in 73. Of course, this is an opportunity for readers to tell their friends, "I told you so," about a drop in the impact risk of 2024 YR4!We've been talking to asteroid hunter David Rankin, who first "precovered" (short for pre-discovery recovery) asteroid 2024 YR4 in data from the Catalina Sky Survey (meaning he was able to find images of the space rock in archival data that was gathered prior to its official discovery) since it hit the top of the Sentry Risk Table. He's been predicting that it's only a matter of time until the odds of an impact dropped significantly. Rankin has been reassuring readers of all along that the risk of 2024 YR4 would climb rapidly and then begin to decrease as astronomers collect more data about the asteroid. The asteroid hunter from the Catalina Sky Survey previously explained how uncertainty in the path of 2024 YR4 arises with an analogy. "Imagine holding a stick that is a few feet long. If you move the stick in your hand a fraction of an inch, you hardly notice any movement on the other end," the researcher said. "Now imagine that stick is many millions of miles long. Moving your hand a fraction of an inch will cause dramatic changes on the other end." "In this case, that 'fraction of an inch' is tiny uncertainties in the positional measurements of the asteroid from the telescopes' images that can arise from small timing errors and small positional errors," Rankin continued. "It's not possible to get a 'perfect' measurement of the asteroid from any telescope." Even if 2024 YR4 misses Earth in 2032, there remains a small chance, about 1 in 125 or 0.8%, that the asteroid could strike the moon. Of course, by far, the most likely outcome is this asteroid missing Earth and its lunar companion and continuing on its path around the sun. Related Stories: — Earth's mini-moon has finally departed. Will it ever return as a 'second moon?' — Asteroid the size of 3 million elephants zooms past Earth — Astronauts could mine asteroids for food someday, scientists say We might have to wait a while until we have more solid info on 2024 YR4's passage through the inner solar system. The asteroid is currently heading away from Earth, but it is set to swing back toward our planet in 2028, once again becoming visible to ground-based telescopes. Even if 2024 YR4 doesn't impact Earth, its scientific impact, as it offers a chance to see an asteroid up close and personal, is immense.
