In the graph on the laptop screen you see a small peak, this is the carrier transmitted by Voyager 1, that took more than 23 hours to reach us.

Receiving Voyager 1 just two weeks ago at Sternwarte Bochum and @amsat-dl.org!

It was a great day! We tracked Voyager-1 Doppler for more than 4 hours. During that time, it stayed well within 1 Hz of predicted values from the published trajectory.

At even higher excitation levels (n=252) we can measure the radio emission in the UHF band (408 MHz).

These lines are weak and take a long integration time (30 minutes+) to become visible. For comparison, this is the H167⍺ RRL at M17 at the same scale as the neutral Hydrogen (HI) profile at M17.

They are essentially the radio counterparts of the Balmer series of lines (n=2), which are visible light lines. In L-band we can detect 4 of these lines, from different energy levels.

These are spectral lines in the radio spectrum that arise from the transitions of electrons between high energy levels in atoms (n>90), when electrons recombine with ions in ionized gas regions, like HII regions.

And the carrier still being received by the historic @radiotelescoop.bsky.social last week Wednesday!

So impressive. And we can still receive the Voyager 1 carrier with the historic 25 meter dish in Dwingeloo @radiotelescoop.bsky.social, as we demonstrated last week Wednesday.

Zooming in on the final minutes of the descent burn, we can see the braking burn transitioning into a hover around 17:28UTC and then a slower descent. At 17:28:45UTC there's a jump in frequency and then a slower leveling off to the Doppler frequency of the Moon. Congratulations on the landing!

Yesterday bouncing Zadoff-Chu sequences off the moon!