Blue Comet Meets Blue Stars
What's that heading for the Pleiades star cluster? It appears to be Comet C/2016 R2 (PanSTARRS) , but here, appearances are deceiving. On the right and far in the background , the famous Pleiades star cluster is dominated by blue light from massive young stars. On the left and visiting the inner Solar System is Comet PanSTARRS , a tumbling block of ice from the outer Solar System that currently sports a long ion tail dominated by blue light from an unusually high abundance of ionized carbon monoxide . Comet PanSTARRS is actually moving toward the top of the image , and its ion tail points away from the Sun but is affected by a complex solar wind of particles streaming out from the Sun. Visible through a small telescope , the comet is fading as it recedes from the Earth, even though it reaches its closest point to the Sun in early May.