Thread by @elakdawalla

Thar they are! Right now Dimorphos and Didymos are both this bright dot of light. They’ll separate into two dots in a little while. #DARTMission

I’ll add photos on to this thread periodically as approach continues.

At the moment, this is the only source for the approach images. If they have not appeared on a website by the time of the post-impact press briefing scheduled for (I think) 5pm Pacific time, I will ask! #DARTmission

So one hour prior to impact, or roughly 35 minutes after this tweet, the #DARTmission photos should start separating the two components of the Dimorphos system.

Meanwhile, Didymos and Dimorphos are still just one bright dot to the #DARTMission DRACO camera.

Under 75 minutes to impact. Still a dot. #DARTMission

Under 70 minutes.

It’s a very narrow angle camera — a long lens — so constant teeny pointing adjustments are being made autonomously by the spacecraft to pointing to keep the asteroid system in the center of the field of view. #DARTmission

Under 65 minutes. Should be separable soon. I’m looking at them under bright sunlight on my iPhone so I can’t really tell, sadly! I’ll be in better viewing conditions closer to impact time. #DARTmission

Under an hour. I’m noticing that the live image feed is behind the impact time by a few minutes. That could be for a variety of reasons, but regardless, I’ll stick with the timeline as reported on the DRACO image feed.

Under 55 minutes

Under 50 minutes

Under 45 minutes to #DARTMission impact

Under 40 minutes to impact, at least on the DRACO image feed.

Under 35 minutes now!

Of course both asteroid and spacecraft are in motion. Spacecraft is steering both with course corrections and with pointing changes (rotation of spacecraft to get target in camera crosshairs)

Under 30 minutes to #DARTMission impact.

Under 25 minutes. I can even see Dimorphos from my phone screen now, a much fainter dot up and to the right of Didymos.

23, 22, 21, 20 minutes to #DARTmission impact (don’t know if I’ll be able to keep this up but I’ll do my best)

19, 18, 17, 16

Lost lock briefly but now under 12 minutes

Under 9 and now clearly targeting moon Dimorphos

Under 7

5

ccoooooollll stuff visible now

cant keep up with tweeting ack

rrrrubbbble pile!!!

Ok I’m now firing up computer to listen to commentated broadcast

Gonna see if I can make a shared album of these screen grabs for people to play with

In the meantime, here are some tweets of highlights:

And here’s the final frame I grabbed off of the #DARTMission DRACO camera live stream before the DART spacecraft ate it in a 6.1 km/s impact. Now waiting for the #LICIAcube images, which will come in much more slowly.

My first and barely-thought-out response is, gosh that looks like Itokawa and Ryugu and Bennu! Gravel pile asteroids in the few hundreds of meters in size are all pretty similar in surface texture.

Gravel-pile NEAR-EARTH asteroids, I should say. These things share a history that includes a perhaps violent event that sent them out of the main belt and onto Earth-crossing or Earth-near paths. They may not look like 100s-of-m bodies still in the main belt.

On the accuracy of #DARTmission's targeting of Dimorphos:

A common phrase around space engineers: "Better is the enemy of good enough." 17 meters off target is just as good 0 meters off target for a 170-meter body; no need for better targeting than that. Stay the course, steady as she goes.

Cheers and well done to the #DARTMission team! I’ll end this particular thread here, but please follow me for more images and commentary, and please consider supporting me at Patreon.com/elakdawalla if you enjoyed my live coverage today.