|By NASA/Goddard/Adler/U. Chicago/Wesleyan [Public domain], via Wikimedia Commons|
Distance: 1 light year from Earth | Content Flag: Public
Once again the unit of distance measurement has changed in the header of my post as we’ve reached a light year from Earth. And it’s taken us 45 years to travel that far – two generations have been born in the time we have flown. That also means that it now takes 2 years for us to send and receive a message, so if I’m a little slow in responding to your questions then I’m sure you understand!
Despite our tremendous speed and the incredible distance that we’ve already covered, we have only actually travelled a twelfth of the full journey. We still have another 189 years until we arrive at Tau Ceti. As you can imagine, to sustain us for that time we take our maintenance very seriously.
Our observations of the Oort cloud have not only proved its existence, but also helped settle some of the questions regarding its composition. Our most recent results established its outer edge. There have been many estimates for its boundary and they varied widely from between 50,000 AU all the way out to 200,000 AU (which is nearly 4 light years). We’ve established that in our direction of travel at least, it ends at just under a light year.
There’s still many mysteries about the Oort cloud and they will need further study by other travellers who will no doubt follow in our wake. We have detected some unexpected structures out here. In particular there are two forms which stand out from the expected distribution. The first are clumps of loosely aggregated comets and smaller bodies. I suspect these are failed planetoids where motions of other bodies have pushed them into coalescing clusters, but lacking the mass needed to accrete into a single body. These aren’t obviously visible and we only detected them after processing the data for the mass analysis of the region we’d passed through.
More puzzling are the loose spirals that we found in the same data. We think that they could be caused by another and much larger body passing nearby, although we haven’t seen any direct evidence of such a body.
As well as reaching another new milestone in human space exploration, we have arrived at a new phase of the mission. As planned, we will now enter low power mode to conserve energy until we reach Tau Ceti. While in this mode the higher functions of the computer system and all active sensors except those needed for navigation are shut down.
That means that I’ll shut down as well, along with the other system command functions. Some automated systems for collision avoidance and basic telemetry will remain operational. We’ll power back up when we start our deceleration burn in 2314. Until then, this is Seb signing off.