The European Space Agency’s Rosetta probe will observe the comet 67P/Churyumov–Gerasimenko as it makes its closest orbit to the sun — known as perihelion.
The probe has stalked the comet for a year and more than 466 million miles. It’s now set to observe a massive ejection of water vapor as the icy object warms in the heat of the Sun.
According to the ESA, the comet is ejecting an equivalent of two bathtubs full of liquid every second.
“Activity will remain high like this for many weeks, and we’re certainly looking forward to seeing how many more jets and outburst events we catch in the act, as we have already witnessed in the last few weeks,” says Nicolas Altobelli, acting Rosetta project scientist.
Along with gas, the ESA estimates the comet sheds 1 ton of dust per second. As a result of those conditions, flight controls have eased Rosetta’s distance from the object.