NASA’s NEO Surveyor mission, planned for launch in 2028, will also add substantially to the asteroid count. Rubin Observatory in Chile begins a wide-angle survey of the sky in 2024 or so, it’s expected to identify thousands of potentially hazardous asteroids. In the longer term, brace yourself for asteroid alerts of this level to become more routine. If the risk assessment changes significantly in the weeks ahead, we’ll update this item to reflect the change. What typically happens is that the error ellipsoid eventually shrinks to a size that leaves out Earth. And it often turns out that astronomers can identify a newly discovered asteroid in archived observations, providing more data points for refining their orbital projections. The more observations you accumulate, the smaller the error ellipsoid becomes. “Often when new objects are first discovered, it takes several weeks of data to reduce the uncertainties and adequately predict their orbits years into the future,” NASA explained in a series of tweets. That uncertainty is visualized as an “error ellipsoid,” with Earth somewhere within the elongated egg-shaped zone of uncertainty. ldlSYJMvMz- PS March 2, 2023Īstronomers emphasized that the risk assessment, which stands at 1-in-670 today, is based on a highly limited amount of data about the asteroid’s orbit around the sun. Surely this possibility will soon be ruled out, however, as an exercise, I calculated where the asteroid might fall if this possibility occurred. With just 3 days of arc, I found about 1 in 400 chance of impact on Feb. (The possibilities range across a line extending from just off the southern tip of India to just off the U.S. Some went so far as to chart where the asteroid might strike if it hit Earth. 2023 DW is currently the only object to have a non-zero rating. NASA took the sighting seriously enough to give it a 1 on the 1-to-10 Torino scale, which is used to rate the risks of near-Earth objects. Its size - described variously as being as big as an Olympic swimming pool, the Leaning Tower of Pisa or 27 pandas - was estimated based on its brightness. It wouldn’t be as deadly as the cosmic impact that killed off the dinosaurs 66 million years ago, which is thought to have been caused by an asteroid 6 to 10 miles wide, but it could spark a global emergency.Īn asteroid search program that’s based in Chile’s Atacama Desert discovered 2023 DW in February, and some of the projections of its trajectory intersected with Earth’s orbit on Feb. A similar smashup in just the wrong place could destroy a city. Such an blast, known as the Tunguska event, took place over Siberia in 1908, leveling hundreds of thousands of acres of remote forest land. If a 50-meter-wide asteroid were to plunge through Earth’s atmosphere, it could create an airburst with as much power as a nuclear bomb. The hubbub over a space rock that could be as wide as 165 feet (50 meters) highlights a couple of trends to watch for: We’re likely to get more of these asteroid alerts in the years to come, and NASA is likely to devote more attention to heading off potentially dangerous near-Earth objects, or NEOs. (Update: After further observations, 2023 DW was removed from the list of potential impacts on March 20.) If the case of 2023 DW plays out the way all previous asteroid scares have gone over the course of nearly 20 years, further observations will reduce the risk to zero. The risk assessment doesn’t have as much to do with the probabilistic roll of the cosmic dice than it does with the uncertainty that’s associated with a limited set of astronomical observations. But despite a NASA advisory and the resulting scary headlines, there’s no need to put an asteroid doomsday on your day planner for that date. A newly discovered asteroid called 2023 DW has generated quite a buzz over the past week, due to an estimated 1-in-670 chance of impact on Valentine’s Day 2046.
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