NASA’s New Horizons team conducts first interstellar parallax experiment

As New Horizons flew to the edge of the solar system, NASA scientists gave it a look back, giving us a chance to see the familiar, unfamiliar sky from another perspective. Also at Wednesday’s launch, project lead researcher Alan Stern added: “The outer sky that New Horizons is currently seeing is very different from what we see on Earth.”

NASA's New Horizons team conducts first interstellar parallax experiment

Imagination (from NASA)

In April, the New Horizons team pointed the lens at Proxima Centauri and Wolf 359. As the closest star to the sun, the neighboring star is about 4.2 light-years apart from us.

At that time, New Horizons was 4.3 billion miles (about 7 billion kilometers) away from Earth. In this case, the scientists decided to perform the first “interstellar parallax” experiment, so they had a comparison chart below.

The so-called parallax refers specifically to observe the offset of the same object from different angles. In the case of human eyes, when you open only your left or right eye, you notice a slight change in perspective (and background) as you look at the thumb sits in front of you, and the target doesn’t appear to be in the same position.

The same method can be used to determine the relative position of a star in space. If you took a picture of a neighboring star on Earth last December and another in June this year, you can estimate the position of the star by angle.

NASA's New Horizons team conducts first interstellar parallax experiment

See the difference between next-door stars from Earth and New Horizons

If the camera is far enough away from Earth, scientists can avoid waiting six months apart. For example, the above image is to observe the parallax contrast image of the neighboring star on Earth and New Horizons.

On April 22 and 23, New Horizons took photos of next-door stars and Wolf 359, respectively. By comparing images taken on Earth at the same time, the team was able to distinguish the parallax shift of the star quite clearly.

Team member Tod Lauer says New Horizons provides us with one of the most powerful inspection experiments to date. Astrophysicist and photography enthusiast Brian May, who helped create the photos, was equally excited about the experiment.