The NASA spacecraft New Horizons has officially conducted its first interstellar parallax experiment. NASA says this is the first time a spacecraft sent images of the sky back to Earth from so far away that the stars appear to be in different positions than we’d see from Earth. New Horizons is currently 4 billion miles from home and was heading towards interstellar space.
New Horizons has traveled so far that it has a unique view of the nearby stars. Researchers say that the spacecraft is looking at an alien sky, unlike what we’d seen from Earth. The stars in the images the spacecraft sent back are visibly displaced from the positions we see on Earth.
On April 22 and 23, the spacecraft turned its long-range telescopic camera on to the closest stars, Proxima Centauri and Wolf 359. The images have shown how the stars would appear in different places than we see from Earth. Researchers use this parallax effect, which is how stars appear to shift against the background when viewed from different locations, to measure the distance to stars.
Researchers say that an easy way for people to get an idea of the parallax effect is to place a finger at arm’s length and watch it seemingly move as you view it with one eye at a time. The New Horizon images were overlaid with pictures of the same stars taken on the same dates by telescopes on Earth, and the shift in position is instantly visible.
At the time of the observations, New Horizons was more than 4.3 billion miles from Earth. The radio signal, which traveled at the speed of light, needed a bit less than six hours and 30 minutes to reach the Earth. New Horizons launched in 2006 and will eventually leave the solar system joining the Voyager spacecraft and Pioneer spacecraft to travel to the stars.