NASA’s New Horizons (NH) probe has made contact with Earth, confirming that it has conducted a successful flyby of Ultima Thule, a bowling pin shaped trans-Neptunian object some 6.5 billion kilometers from our planet. This is the most distant ever exploration of an object in the solar system. The probe has also acquired several gigabytes worth of photos and other observations which it will send back to Earth over the coming months.
Radio messages from NH were received by one of NASA’s antennas in Madrid six hours and eight minutes after being sent by the probe. Apart from confirming the successful flyby, the first message contained engineering information on the spacecraft’s status as well as a message saying the probe’s onboard memory was full.
Information cannot be exchanged in real time between the spacecraft and Earth because of the massive distance that needs to be traversed by signals and also because NH is only equipped with a small, 15-watt transmitter. Data transmission rates max out at 1 kilobit per second. Because of this, it is expected that Earth will not receive all the pictures taken by NH until 2020. However, NASA expects it will receive the first of the high resolution images taken by the probe by February 2019.
Ultima Thule is located in what is known as the Kuiper belt — a ring of frozen material which orbits the sun at 1.5 billion km beyond the dwarf planet Pluto, which NH visited in 2015. Scientists estimate that there are hundreds of thousands of similar icy worlds like Ultima Thule here and that they could offer clues on the formation of our solar system. This is because all chemical reactions in this region have stalled because of the very low temperature.
NASA scientists have expressed hope that the NH probe’s course can be slightly altered so it can visit at least one more object in the Kuiper belt within the next decade. According to them, it should have just enough fuel reserves to be able to do this. They expect the probe has sufficient electrical reserves to keep operating its instruments into the 2030s.