In the distance of the light of civilization, the unobstructed view of the night sky makes you feel as if you are on the brink of eternity. But there is a place on Earth where places of interest extend a little further than anywhere else.
Researchers have measured the clarity of stars at a major Antarctic research station and found that it exceeds current highs for astronomy. The result may not be surprising, but for most of us, it’s a bit disappointing.
Dome A is the highest ice dome on the Antarctic polar plateau. More than 4 kilometers (more than 13,000 feet) above sea level and located about 1,200 kilometers from the ocean in the middle of the coldest continent, it is bound to be cold.
In fact, temperatures can drop to -90 ºC (-130 Fahrenheit).
However, if that doesn’t stop you, the rewards would be worth your effort.
This icy peak provides an astronomical perspective like no other, with a relatively unobtrusive view of light pollution spots, the interference of numerous passing satellites, or even the occasional passing cloud.
“A telescope located in Dome A could make a similar telescope located anywhere else on the planet,” says Paul Hickson, an astronomer at the University of British Columbia (UBC).
“The combination of high altitude, low temperature, long periods of continuous darkness and an exceptionally stable atmosphere, makes the dome a very attractive place for optical and infrared astronomy. A telescope located there would have sharper images and could detect weaker objects “.
If you really want to see further into the depths of space and time, you will have to escape from the part closest to the atmosphere called the boundary layer. The gases that make up this thin blanket are not only clogged with dust and moisture; the heat from the ground makes it brighter, which is why the stars seem to glow.
One way to quantify this annoying mess is through a figure called astronomical vision, which is a description of the apparent diameter of the light source in units called arc seconds.
This number means the difference in distinguishing a point of light as a source or multiple, so that the less turbulence and clearer the vision, the smaller the object (and therefore the shorter the arc).
Right now, the best ground-based telescopes available to astronomers are at elevations where the boundary layer is relatively thin.
Currently, the high Atacama Desert in Chile is considered one of the most prominent places for telescopes, home to the large Atacama millimeter array for radio imaging, and which will soon house the huge giant Magellan telescope, a beast that surpassed Hubble.
In this corner of the globe, atmospheric conditions can provide astronomical figures with regular vision of up to about 0.66 arcseconds. On some clear nights, that number could even drop by half for a few hours here and there.
Hickson and his collaborators measured the astronomical view of the Kunlun station at Dome A, a Chinese research site already considered an attractive site for astronomers.
Another cold place in inland Antarctica called Dome C already had estimated values of 0.23 to 0.36 arcseconds. But no one had a good measure with those in the dome A.
Placing its measuring equipment 8 meters from the ground, the team recorded numbers as low as 0.13 seconds of arc, which places it on the dance floor of the observatories outside the atmosphere. In fact, the number reflects a boundary layer only 14 meters thick.
“After a decade of indirect testing and theoretical reasoning, we finally have direct observational evidence of the extraordinarily good conditions at Dome A,” says astronomer Michael Ashley of the University of New South Wales in Australia.
Before you pack your bags and your old trusted telescope to spend a star-studded night, you should know the conditions of Dome A, you won’t be threatened by frost. Your team should be at the forefront.
“Our telescope observed the sky fully automatically at an unmanned Antarctic station for seven months, with the air temperature dropping to -75 degrees Celsius at times. In itself, this is a technological breakthrough,” he said. says the study’s lead author, UBC astronomer Bin Ma.
Even with advanced technology that could be operated from a warmer place, the team had to deal with the scourge of ice. Overcoming the hurdle of extreme temperatures could help you see even further, by about 12 percent.
While most reading this will never see the clear conditions of Dome A, but we will all be able to benefit from the universal visions of the great astronomy projects that will be installed in the future.
This research was published in Nature.