We’ve been tracking a new asteroid named 2023 DW that has a very small chance of impacting Earth in 2046. 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. (1/2) pic.twitter.com/SaLC0AUSdP
— NASA Asteroid Watch (@AsteroidWatch) March 7, 2023
On February 27, 2023, astronomers discovered a new asteroid that they’ve labeled 2023DW. At this moment, ESA’s Near-Earth Objects Coordination Center is listing the asteroid as having a 1-in-560 chance of striking Earth on Valentine’s Day, February 14, 2046. That’s a comfortable 99.82% chance that 2023DW will miss Earth. But, still, there’s a lot of chatter about this asteroid.
In the coming days and weeks, we’ll have more observations of 2023DW, which will further refine our knowledge of the asteroid’s orbit. And, as almost always happens with new discoveries like these, we’ll likely learn there’s no chance the asteroid will strike us.
As of Thursday, March 9, 2023, the analysis of its orbit was based on just 62 observations spanning 6.8487 days, through March 4, 2023.
As a thought experiment, Italian astronomer Piero Sicoli did his own math to figure out the odds of impact and the possible location of where the strike would be. He shared his results on Twitter:
#2023DW. With just 3 days of arc, I found about 1 in 400 chance of impact on Feb. 14, 2046 (JPL 1/770). Surely this possibility will soon be ruled out, however, as an exercise, I calculated where the asteroid might fall if this possibility occurred. pic.twitter.com/ldlSYJMvMz
— PS (@Piero_Sicoli) March 2, 2023
Last chance to get a moon phase calendar! Only a few left.
More on asteroid 2023DW
So all of these results are extremely preliminary, with so few observations.
But, that said, as of this moment, astronomers are estimating the asteroid is 165 feet (50 meters) in diameter. (Watch a video of size comparisons in asteroids.) While 50 meters isn’t anything near a planet-ending-sized rock, it would leave a mark in whatever region it hit, if indeed it should strike.
In fact, the Chelyabinsk meteor – which exploded in the air over Russia in 2013 – was a little under half the size of the estimate for 2023DW.
Currently a 1 on the Torino scale
Also, 2023DW currently has a Torino score of 1. That’s an exceedingly rare score. But even the very rare Torino score of 1 (instead of 0) is nothing to be worried about. A score of 1 means:
A routine discovery in which a pass near Earth is predicted that poses no unusual level of danger. Current calculations show a collision is extremely unlikely with no cause for public attention or public concern. New telescopic observations very likely will lead to reassignment to Level 0.
Richard Binzel of the Massachusetts Institute of Technology, the inventor of the Torino scale, spoke with EarthSky. He explained that it’s not unusual to see the numbers go up as we learn more about the object’s orbit. In these cases, we are just narrowing the line of uncertainty. The closer the asteroid will be to Earth, the more the numbers will go up until we eliminate its possibility of hitting Earth, at which case the asteroid will drop down to category zero.
This has been the case with 2023DW. It originally had around a 1-in-700 chance of hitting Earth, which is now 1-in-560 as we learn more about its orbit. As for when we’ll get the expected “all clear” that 2023DW will definitely not hit Earth, Binzel said:
Optimistically, we’ll know more in a few weeks.
More objects on the Torino scale in the future
Asteroid 2023DW provides a great opportunity for us to understand the Torino scale and how objects move on and off the list. We might as well get comfortable with asteroids temporarily at a Torino score of one or more, because they will become more common in the future, Binzel said. Why is that? It’s not because there are suddenly more of them, it’s because our increasing technology allows us to see these objects that we previously missed. Binzel said we could have up to a dozen objects at a time that are a non-zero on the Torino scale.
Future observatories, such as the Vera Rubin Telescope, the NEO Surveyor and NEOMIR, will be able to spot smaller objects. In fact, our increasing technology has already allowed us to start spotting more of these objects that actually have impacted Earth. As Binzel explained, objects like these are hitting Earth all the time, often over the ocean, we just didn’t know about them beforehand.
Just last month, Krisztián Sárneczky of Hungary discovered an asteroid just hours before it impacted over France, creating a brilliant light show and dropping small meteorites over the countryside. There was another recent case in Canada in November 2022, plus another in March 2022 over the Arctic, which was also discovered by Sárneczky!
So if you’re a fan of asteroids and meteors, the future is looking up.
Bottom line: Astronomers are monitoring the newly discovered asteroid 2023DW. It has a 1-in-560 chance of striking Earth on February 14, 2046. That’s a comfortable 99.82% chance that 2023DW will miss Earth.
