ESA's Solar and Heliospheric Observatory (SOHO) spotted a short-period comet on October 25. Before heading towards its original space, the comet moved up and around the SOHO's view for many days.
During that same period, NASA's Solar and Terrestrial Relations Observatory (Stereo) mission also captured Comet 96P from the opposite side of Earth's orbit, between October 26-28.
This is a rare phenomenon when two comets were seen simultaneously from two different locations in space. The comet entered the bottom of Stereo's view and crossed it diagonally before leaving on October 28.
However, the close encounter of comet also allowed researchers to obtain the most comprehensive parallel observations of comet 96P.
Comet 96P is also known as Machholz, completes an orbit around the Sun every 5.24 years.
The scientists gathered polarization measurements of the comet, besides the size and trajectory. They measured an amount of sunlight passing through a medium and particles in the tail of the comet, which allows scientists to gain more insight into the comet's composition.
“Polarization is a strong function of the viewing geometry, and getting multiple measurements at the same time could potentially give useful information about the composition and size distribution of the tail particles.”William Thompson, STEREO chief observer at NASA's Goddard Space Flight Center said in a statement.