Intercepting 3I/ATLAS at Closest Approach to Jupiter with the Juno spacecraft

TL;DR

This paper proposes a mission plan using Juno spacecraft's maneuvers to intercept and closely approach the interstellar object 3I/ATLAS near Jupiter, enabling detailed study beyond telescopic observations.

Contribution

It demonstrates a feasible trajectory and fuel-efficient maneuvers for Juno to intercept 3I/ATLAS at close distances, optimizing mission parameters for scientific exploration.

Findings

Juno can intercept 3I/ATLAS with a total ΔV of 2.6755 km/s.

A close fly-by at 27 million km is possible with 5.4% of initial fuel.

Using a second impulse can significantly reduce propellant use for closer approaches.

Abstract

The interstellar object 3I/ATLAS is expected to arrive at a distance of $53.56(\pm 0.45)$ million ${\rm km}$ ($0.358\pm 0.003$~au) from Jupiter on March 16, 2026. We show that applying a total thrust $\Delta$V of $2.6755 {{\rm km~s^{-1}}}$ to lower perijove on September 9, 2025 and then execute a Jupiter Oberth Maneuver, can bring the Juno spacecraft from its orbit around Jupiter to intercept the path of 3I/ATLAS on March 14, 2026. We further show that it is possible for Juno to come much closer to 3I/ATLAS ($\sim{27}$ million km) with 110 kg of remaining propellant, merely 5.4% of the initial fuel reservoir. We find that for low available $\Delta$V there is no particular benefit in application of a double impulse (for example to reach $\sim{27}$ million km from 3I/ATLAS), however if Juno has a higher $\Delta$V capability there is significant advantage to a second impulse with typically a saving of propellant by a factor of a half. A close fly-by might be able to probe the nature of 3I/ATLAS far better than telescopes on Earth.