Radar Detection of 2013 ET
- Hi Everyone,
Thank you again to everyone who has observed 2013 ET and reported astrometry.
It was absolutely essential and it enabled us to detect radar echoes from
2013 ET at Goldstone earlier today.
The radar signal-to-noise ratios were stronger than expected and we obtained
images with a range resolution as fine as 7.5 meters/pixel, but even so, the
images barely resolve the object into a few range rows because 2013 ET is
so small. We measured a number of Doppler and time-delay corrections
to the ephemeris and really nailed the orbit, so we don't need any more
The Doppler broadening (aka the bandwidth) of the echoes varies as
the asteroid spins, so clearly it's somewhat elongated, and there are
hints of irregularity in the shape in the images. We're planning to
release some images after the track on March 10 when we should see
more detail if things go well.
Lance Benner, Marina Brozovic, & Jon Giorgini