3I/ATLAS Looking to Target Jupiter’s Hill Radius?
3I/ATLAS, the interstellar object, is expected to reach its closest distance from Jupiter on March 16, 2026. The object may enter Jupiter’s Hill radius, the region where Jupiter’s gravity dominates over the Sun’s. This makes the Hill radius important for understanding potential satellite orbits and possible extraterrestrial activity.
What is Jupiter’s Hill Radius?
The Hill radius is the maximum distance from a planet where its gravity can hold satellites despite the Sun’s influence. Inside this radius, Jupiter’s gravity exceeds the Sun’s tidal forces. Lagrange points L1 and L2 are located at the Hill radius, ideal for low-energy orbits and technological devices.
The Hill radius (H) is calculated as:
H = R * (m / 3M)^(1/3)
where R is Jupiter’s distance from the Sun, m is Jupiter’s mass, and M is the Sun’s mass.
When will 3I/ATLAS Approach Jupiter?
On March 16, 2026, Jupiter will be 783.8 million kilometers from the Sun. Using the Hill radius formula, the Hill radius is calculated as 53.502 million kilometers. NASA’s JPL Horizons code, using data from 230 observatories, predicts the minimum distance of 3I/ATLAS from Jupiter as 53.445 (+/- 0.06) million kilometers. The closeness of these two values is remarkable. The near match suggests 3I/ATLAS may reach the outer edge of Jupiter’s gravitational influence.
3I/ATLAS Non-Gravitational Acceleration and Course Correction
3I/ATLAS experienced non-gravitational acceleration near perihelion, measured at 5×10^-7 au per day squared. This caused a small trajectory shift, enough to align the minimum distance with Jupiter’s Hill radius. Without this correction, 3I/ATLAS would have missed the Hill sphere.
If 3I/ATLAS is technological, thrusters may have adjusted its path to target Jupiter’s Hill radius. Observed jets around the object after perihelion could indicate minor course corrections. These maneuvers are optimal near perihelion to use the Sun’s gravitational assist.
Statistical Rarity of the Coincidence
The difference between the calculated Hill radius and 3I/ATLAS minimum distance is within 0.06 million kilometers. This is a coincidence of one part in 1,000. Considering Jupiter’s full orbital diameter, it corresponds to a chance of one part in 26,000.
Implications for Jupiter and Extraterrestrial Technology
If 3I/ATLAS deposits devices in Jupiter’s Hill sphere, they would need to counter its high speed relative to Jupiter, 65.9 km/s. The escape speed at the Hill radius is only 2.2 km/s.
Future observations by Juno or other orbiters could detect new objects near Jupiter. Finding unexpected devices would suggest extraterrestrial interest in Jupiter. A lack of similar objects near Earth could indicate that 3I/ATLAS is not targeting our planet.
FAQs
Q1: What is Jupiter’s Hill radius?
Jupiter’s Hill radius is the maximum distance where its gravity dominates over the Sun, allowing satellites or objects to remain bound to Jupiter.
Q2: How close will 3I/ATLAS come to Jupiter?
3I/ATLAS will approach 53.445 million kilometers from Jupiter on March 16, 2026, very near the Hill radius.