A human silhouette watching the interstllar space probe move across the sky

Interstellar space probe to boldly go even further

A new interstellar space probe, currently in its planning phase, will boldly go where no probe has gone before according to a new paper due for presentation at this year’s European Geosciences Union (EGU) General Assembly.

The NASA probe, currently dubbed the Interstellar Probe, will go further into interstellar space (the area of space between star systems) than the two Voyager spacecraft – the first probes ever to reach interstellar space in 2012 and 2018 – which were released more than thirty years ago.

When it gets there, some 1,000 astronomical units from the Sun, it will turn its gaze back towards home and begin a journey of discovery about our heliosphere – the bubble of space that encompasses the Solar System, and that is affected by solar winds from the Sun.

“The Interstellar Probe will go to the unknown local interstellar space, where humanity has never reached before,” says Elena Provornikova, the Interstellar Probe heliophysics lead from the Johns Hopkins Applied Physics Lab (APL) in Maryland, US. “For the first time, we will take a picture of our vast heliosphere from the outside to see what our solar system home looks like.”

Scientists plan for the Interstellar Probe to reach 1,000 AU – 1 AU is the distance from the sun to Earth – into the interstellar medium. That’s about 10 times as far as the Voyager spacecraft have gone. Credit: Johns Hopkins APL

It harks back to the moment, on the 14th February 1990, when astronomer Carl Sagan directed NASA engineers to turn the Voyager 1 probe around and snap one final image of Earth, a pale blue dot which appeared a “mote of dust suspended in a sunbeam,” and changed our perspective on our place in the cosmos.

This time, the team hopes to unveil mysteries around the Sun’s interaction with the space around it – how the Sun’s plasma reacts with interstellar gas to create the heliosphere, what lies beyond the heliosphere, and what the heliosphere looks like.

The probe would take images of the heliosphere using energetic neutral atoms, and even seek to “observe extra-galactic background light from the early times of our galaxy formation – something that can’t be seen from Earth,” says Provonikova.

The heliosphere is important for understanding how our solar system interacts with the space around it. This is particularly crucial because the heliosphere shields our Solar System from high-energy galactic cosmic rays.

Currently, the Solar System is in what’s known as the Local Interstellar Cloud, but Provornikova says recent research suggests it is inching toward the edge of the cloud and will ultimately end up in a new region of interstellar space, about which we know nothing.

These movements could make our heliosphere change in size, or alter the amount of cosmic rays entering the solar system and contribute to background radiation levels on Earth.

At the end of this year, the team will deliver a report to NASA outlining the potential mission design. The mission itself could launch in the early 2030s and is designed to last at least 50 years. The probe would take around 15 years to reach the boundary of the heliosphere – outpacing the 35 years the two Voyager probes took to get there.


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