The Herschel Mission Closes Its Eye
Photo by ESA/NASA/JPL-Caltech/N. Billot (IRAM)
Phil Plait: slate.com
On May 14, 2009, the European Space Agency launched the infrared astronomical observatory Herschel into space. For very nearly four years, this fantastic telescope observed the Universe and returned high-resolution far-infrared data to scientists on Earth.
Sadly, the mission is now over. Yesterday, engineers reported a temperature spike in all the instruments on board, indicating the supply of liquid helium had finally run out. This ultra-frigid fluid was needed to cool the cameras so they could get clear views of some of the coldest objects in space. Without the helium, the detectors can no longer function optimally.
It’s bittersweet news; liquid helium evaporates, and even though Herschel started with 2300 liters, it had to run out eventually. The lifetime was estimated at just over three years, so we actually got some extra mileage out of it.
And the legacy of Herschel is secure. It took tens of thousands of observations, including some of the most exotic and beautiful images of the sky I’ve seen.
Click the link to see more of the amazing images Herschel took.