The New Horizons mission is an unmanned NASA space mission to explore Pluto, its satellites, and the Kuiper belt. The probe was launched in 2006 on its way to Jupiter, where it arrived in March 2007. It then reached the closest point to Pluto on July 14, 2015. After leaving Pluto behind, the probe will fly over part of the Kuiper belt. Well, one of the tools on board, the Long Range Reconnaissance Imager (LORRI) , has proven very useful for measuring the brightness of all galaxies . In a study published in Nature Communications , Michael Zemkov, a researcher at the Rochester Institute of Technology, used archival data from LORRI to measure visible light from other galaxies beyond the Milky Way, known as the cosmic optical background . Zemcov’s findings give an upper limit to the amount of light in the cosmic optical background.
“Determining the amount of light coming from all the galaxies beyond our Milky Way is a challenge for observational astrophysics,” according to Zemcov. Cosmic optical background light can reveal the number and location of stars, how galaxies work, and the peculiar nature of exotic physical processes, such as the light that can be produced when dark matter disintegrates. This invisible substance comprises 85% of the matter in the universe . For Zemkov, the possibility opens up “to carry out astronomy studies from outside the solar system. We see that the optical background is completely coherent with the light from the galaxies without the need to add more brightness, while previous measurements from Earth need a lot extra brightness. It is proof that this type of measurement is possible and that LORRI is the tool capable of doing it. “
Spacecraft traveling beyond the solar system give scientists premium insight into the cosmic optical background . Faint light from distant galaxies is difficult to see from our solar system, because it is polluted by the glare of sunlight reflected off interplanetary dust. Cosmic dust is made up of fragments of rock and tiny bits of soot that move from outside the solar system toward the Sun. Scientists conducting experiments on probes and satellites record the dust that makes the atmosphere much brighter than the cosmic optical background.
NASA’s New Horizons mission will be operational until 2021, so Zemcov hopes to be able to use the LORRI (Long Range Reconnaissance Image) to re-measure the brightness of the cosmic optical background. NASA sends missions to the outer solar system every decade or so. Normally the instruments they carry on board are designed to observe planets and not to do astrophysics. But Zemcov believes the measurements could be designed to optimize this technique as long as LORRI continues to operate.
Zemcov’s method dates back to NASA’s first long-distance missions Pioneer 10 and 11 in 1972 and 1974. Light detectors on the instruments measured the brightness of objects outside the Milky Way and took the first direct reference point. of the cosmic optical background.
