Rosetta spacecraft collects strange UV readings from comet

You might also like

Tesla driverless system to use updated radar technology

12/09/2016

Apple to develop its own self-driving technology

10/09/2016

MALI: The Rosetta spacecraft orbiting around the comet 67P/Churyumov-Gerasimenko (67P) has recorded strange data in ultraviolet readings from the icy body. This announcement comes at the same time as NASA announced a proposed plan to crash the orbiter into the comet near the site where the Philae lander came to rest after an unsuccessful touchdown.
Comets can be thought of as dirty snowballs, in many respects. As they approach the sun, comets warm up, releasing carbon dioxide (CO2) and water through jets within their bodies. As these molecules rise, they are usually split apart by the action of photons of ultraviolet light from our parent star.
Atoms of hydrogen (from water), oxygen (from water and carbon dioxide) and carbon from CO2 each emit and absorb photons at specific frequencies. These can be measured from Earth, but not in the detail seen by Rosetta, currently circling the comet.
Researchers examining the phenomenon believed that photons of electromagnetic energy were driving the changes on 67P. But the Alice ultraviolet spectrograph onboard the Rosetta observatory found that nearly all of the observed molecular breakdowns surrounding the comet were actually driven by electrons.
“First, an ultraviolet photon from the sun hits a water molecule in the comet’s coma and ionizes it, knocking out an energetic electron. This electron then hits another water molecule in the coma, breaking it apart into two hydrogen atoms and one oxygen, and energizing them in the process. These atoms then emit ultraviolet light that is detected at characteristic wavelengths by Alice,” the European Space Agency (ESA) reported.
Astronomers could now utilize Alice to trace the jets of water and CO2 emissions down to their sources on the surface of the comet. This study could help researchers better understand the nature of cometary formation and development.