A NASA experiment, along with the New Horizons, shows the probe now sees some stars in slightly different positions than we do on Earth. It shows how far from home the spacecraft is.
The space agency has used the spacecraft for the first time to produce this kind of "parallax effect." Researchers have been using this "parallax effect" for a long time. This phenomenon describes how, when viewed from various places, a star tends to move against its backdrop to determine distances between stars.
Scientists said that one can imitate this by holding a finger about the length of an arm and watching it jump back and forth as you view it with each eye, NASA's release said.
As for the distance, so to speak, between the left and right eyes, that is the distance between Earth and New Horizons, now 6.9 billion kilometers away. As you can remember, New Horizons visited Pluto in 2015, and the oddly shaped Arrokoth asteroid in early 2019. The spacecraft is now hurtling at 50,700 kilometers per hour toward interstellar space.
ALSO READ: After Pluto, NASA's New Horizons Spacecraft Heads To Kuiper Belt
Stereoscopic milestone
The stars seemed to be in various positions through the parallax effect, meaning that the stars appeared to move towards the background because New Horizons was seeing it from a different view point. The parallax effect is used by scientists to measure the distances to stars.
Stars are always moving, including our Sun. But Earth so far from these stars and they're running over such big time scales that it's hard to see that motion.
"No human eye can detect these shifts," said Alan Stern, the principal investigator for the New Horizons project.
The images captured by New Horizons could. However, be compared with pictures taken by Earth-based telescopes on the same days, which made the shift evident.
Images from the ground were captured by scientists from the Las Cumbres Observatory operating a telescope at the Australian Siding Spring Observatory and astronomers operating a remote telescope at the Arizona Mount Lemmon Observatory, remotely.
ALSO READ: NASA Pushes Back Mars Perseverance Rover, James Webb Telescope Launch Again
Largest parallax baseline ever
NASA performed this experiment back in late April. During that time, New Horizons took pictures of these two close stars using its long-range telescopic camera. Telescopes in Australia and Arizona at the same time took pictures of those stars back on Earth.
"The New Horizons experiment provides the largest parallax baseline ever made - over 4 billion miles (6.4 billion kilometers)," said Tod Lauer, a New Horizons science team member, in a statement. He said the experiment is the first demonstration of an easily observable stellar parallax.
The images captured by New Horizons could however be compared with pictures taken by Earth-based telescopes on the same days, which made the shift evident.
Images from the ground were captured by scientists from the Las Cumbres Observatory operating a telescope at the Australian Siding Spring Observatory and astronomers operating a remote telescope at the Arizona Mount Lemmon Observatory, remotely.
"It's fair to say that New Horizons is looking at an alien sky, unlike what we see from Earth," Stern said. "And that has allowed us to do something that had never been accomplished before - to see the nearest stars visibly displaced on the sky from the positions we see on Earth."
One cool aspect of this experiment is that these two frames give Proxima Centauri and Wolf 359 a 3D perspective, or stereoscopic view. More New Horizons parallax images can be downloaded here including 3D views.
