Oops! In a happy accident, Comet Lovejoy just happened to be in the field of view of the 570-megapixel Dark Energy Camera, the world’s most powerful digital camera. One member of the observing team said it was a “shock” to see the comet pop up on the display in the control room.
"It reminds us that before we can look out beyond our galaxy to the far reaches of the Universe, we need to watch out for celestial objects that are much closer to home!” the team wrote on the Dark Energy Detectives blog.
Comet Lovejoy (C2014 Q2) entered the camera's view last Dec. 27 while the Dark Energy Survey was scanning the southern sky. The rectangles in the mosaic image are among the 62 individual fields of the camera.
At the time this image was taken, the comet was passing about 51 million miles (82 million kilometers) from Earth. That’s a short distance for the Dark Energy Camera, which is sensitive to light up to 8 billion light-years away. The comet’s center is a ball of ice roughly 3 miles (5 kilometers) across, and the visible head of the comet is a cloud of gas and dust about 400,000 miles (640,000 kilometers) in diameter.
The Dark Energy Survey is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by tracing the nearly 14 billion-year history of cosmic expansion with high precision. The camera just finished up the third, six-month-long season of observations, and the camera won’t be observing again until this fall.
You can download higher-resolution versions of this image here.
— Nancy Atkinson, Universe Today
Nancy Atkinson is Universe Today's senior editor. This report was originally published by Universe Today on Feb. 27, with the headline "Dark Energy Camera Takes Accidental Gigantic, Magnificent Picture of Comet Lovejoy." Copyright 2015 Universe Today, reprinted with permission.