Got any plans for tonight? No? Well then you’re in luck, because NASA is just a few hours from intentionally smashing a probe into the minor planet Dimorphos as part of Double Asteroid Redirection Test (DART) — marking the first time humanity has ever intentionally tried to knock a space rock off-course. If it works, we’re one step closer to having a viable planetary defense system in case we ever detect an asteroid on a collision course with Earth. If it doesn’t work. . . well, we’ve still got time to come up with another plan.
To be clear, the 170 meter (560 feet) wide Dimorphos DOES NOT pose any threat to us, nor will it after NASA smacks it around with an ion-propelled spacecraft. This is simply a test to see if a small spacecraft impacting an asteroid head-on can slow it down enough to appreciably change its orbital trajectory. We won’t know for a week or so if the impact did the trick, but it should still be fascinating to watch the crash happen live.
We’ve embedded the two NASA streams below. The first one will start about a half an hour before impact and is going to show live navigational images of Dimorphos as the DART spacecraft zeros in on its target, and the second stream will cover the main event. Keep in mind this isn’t a Hollywood film we’re talking about — don’t expect any dramatic explosions when the clock hits zero. When the telemetry stops coming back, that means it was a bullseye.
In the early morning hours of August 10th, a support cable at the Arecibo Observatory pulled lose from its mount and crashed through the face of the primary reflector below. Images taken from below the iconic 305 meter dish, made famous by films such as Contact and GoldenEye, show an incredible amount of damage. The section of thick cable, estimated to weigh in at around 6,000 kilograms (13,000 pounds), had little difficulty tearing through the reflector’s thin mesh construction.
Worse still, the cable also struck the so-called “Gregorian dome”, the structure suspended over the dish where the sensitive instruments are mounted. At the time of this writing it’s still unclear as to whether or not any of that instrumentation has been damaged, though NASA at least has said that the equipment they operate inside the dome appears to have survived unscathed. At the very least, the damage to the dome structure itself will need to be addressed before the Observatory can resume normal operations.
But how long will the repairs take, and who’s going to pay for them? It’s no secret that funding for the 60 year old telescope has been difficult to come by since at least the early 2000s. The cost of repairing the relatively minor damage to the telescope sustained during Hurricane Maria in 2017 may have been enough to shutter the installation permanently if it hadn’t been for a consortium led by the University of Central Florida. They agreed to share the burden of operating the Observatory with the National Science Foundation and put up several million dollars of additional funding.
It’s far too early to know how much time and money it will take to get Arecibo Observatory back up to operational status, but with the current world situation, it seems likely the telescope will be out of commission for at least the rest of the year. Given the fact that repairs from the 2017 damage still haven’t been completed, perhaps even longer than that. In the meantime, astronomers around the globe are left without this wholly unique resource.