NASA’s New Horizons spacecraft continues to send data back to Earth to help scientists determine when it reaches interstellar space. A team of researchers at the Southwest Research Institute is analyzing Pluto’s solar wind (SWAP) instrument on New Horizons to learn more about what will happen to the solar wind in the outer solar system.
New Horizons approaches Pluto’s imagination (photo: NASA, via New Atlas)
The center of the solar system looks like a super-invincible nuclear bomb, and the vacuum around it is scattered with many unusually hard tiny solids, but the solar wind is almost all-encompassing.
The constant flow of ionized particles produces light that can be seen on planets. But around the solar system, there are uneven “bubbles”.
Here, the solar wind is reduced to subsonic due to interaction until it is completely blocked by the interstellar medium. Scientists call it the “Termination Shock” and the “Heliopause” layer.
The outer boundary of the heliosphere is where New Horizons can encounter interstellar space material. (Pictured from: Southwest Research Institute)
To measure the interaction between the sun and the stars, NASA equipped the New Horizons spacecraft with SWAP instruments. Now scientists have confirmed that as the distance gets farther and farther, the sun’s wind speed becomes slower.
Previously, although humans have launched the Pioneer 10/11 and Voyager 2/1 spacecraft, they have never carried such sophisticated equipment to pick and detect solar wind (and even interstellar ions).
These are stray neutral atoms that are ionated by sunlight. According to southwest research, SWAP is able to extract and measure low-volume interstellar ions with unprecedented resolution and coverage.
Instrument kit on New Horizons (photo: NASA)
New Horizons is currently located about 46 astronomical units (4.3 billion miles / 6.8 billion kilometers) away from the sun. Scientists expect the solar wind to interact when it encounters interstellar matter, causing a marked slowdown and warming.
For the purposes of the study, the team analyzed the solar wind speed measurements of SWAP at a distance of 21 to 42 astronomical units.
By comparing measurements with measurements of NASA’s Advanced ComponentS Probe (ACE) and Solar-Earth Relations Observatory (SOLAR) spacecraft at the same astronomical unit distance (93 million miles / 149 million km), it has shown that such an event is occurring.