3 ms·
No mention of the actual change is speed, only its orbital period around its partner. Also no mention of changes in the orbit of the pair around the sun. It's c
by phkahler 4y ago
No mention of the actual change is speed, only its orbital period around its partner. Also no mention of changes in the orbit of the pair around the sun. It's cool to have both, but the bigger picture is more important even though the effect is certainly less impressive sounding.
- Retric 4y agoThe prediction was Dimorphos would slow between 1.75 cm/s and 2.54 cm/s ~0.05 mph. However, it is easier to measure orbital period vs velocity so we might not have velocity yet.
- nsilvestri 4y agoYou can derive it yourself. Dimorphos's orbital eccentricity is pretty low, meaning you can use: mean_orbital_velocity = 2 * pi * semimajor_axis / period As for the orbit around the sun, the parent body Didymos is about 100x more massive, so any change in the center of mass from this impact will have, in the short term, negligible effects on their orbit around the sun.
- sega_sai 4y agoNo, that is not correct thing to use, as the semimajor axis will change as well. What is needed is the third Kepler law. The semimajor axis will be period^(2/3). And then speed will be period^(-1/3). Thus if period was changed here by roughly 5%, the speed changed by 1.6%
- arlort 4y ago> Also no mention of changes in the orbit of the pair around the sun It would be worrying if there were as that's not what the test was supposed to achieve nor measure