T-1 Day For 3I/ATLAS: Virtual Telescope To Stream Interstellar Visitor Flyby

In just a few hours, the sky will play host to a rare celestial wanderer that hasn't just travelled from across the street, but from across the galaxy. 3I/ATLAS, only the third interstellar object ever detected in our solar system, is hurtling towards its closest encounter with Earth.

This ancient traveller, moving at a blistering speed of 144,100 mph, is currently finishing its one-and-done tour of our neighbourhood, leaving scientists and stargazers alike scrambling for a final look before it vanishes into the dark forever.

We are now officially T-1 day away from the closest approach of this mysterious interloper. While the flyby is scheduled for the early hours of Friday, 19th December, the window to witness this cosmic passing is closing fast.

At its nearest point, 3I/ATLAS will sit about 168 million miles (270 million kilometres) from Earth—nearly twice the distance between our planet and the Sun. Although that sounds like a vast divide, in the grand theatre of space, it is close enough for us to peer into the secrets of a distant star system.

The Science Of A Spinning Interstellar Visitor

Despite the feverish speculation that often surrounds such rare events, NASA has been clear about the object's nature. During a long-awaited briefing in November, NASA Associate Administrator Amit Kshatriya addressed the 'Oumuamua-style' rumours directly. 'We very much want to find signs of life in our universe,' he explained, 'but 3I/ATLAS is a comet'.

Yet, being 'just a comet' hasn't stopped 3I/ATLAS from breaking records. For the first time in history, astronomers have detected a 'wobbling jet' on an interstellar object. Using the Two-meter Twin Telescope at Tenerife's Teide Observatory, researchers spotted a faint blast of gas and dust that rhythmically wobbles as the comet spins.

This discovery allowed scientists to calculate its rotation period—one full turn every 14 to 17 hours—marking the first time we have directly measured the spin of a visitor from another star.

What makes this particularly fascinating is how 'normal' the comet appears. Despite its alien origins, it behaves remarkably like the comets born here in our own solar system, responding to the warmth of our Sun with familiar, sunlight-driven jets.

X-Ray Glows and Interstellar Chemistry

The sheer scale of the activity surrounding the comet is staggering. Observations from the European Space Agency's XMM-Newton observatory have revealed a vast X-ray glow stretching 250,000 miles (400,000 kilometres) from the comet's nucleus.

This ghostly light is produced as the comet's gases collide with the high-energy particles of the solar wind.

By studying this spectral fingerprint, scientists are essentially reading a history book of a solar system we will never visit. The comet reached its perihelion—its closest point to the Sun—on 30th October and is now speeding away, well beyond the orbit of Mars.

After its encounter with Earth, its next stop is Jupiter in March 2026, before it exits our heliosphere and returns to the interstellar void.

How To Watch The 3I/ATLAS Flyby Live

If you are hoping to catch a glimpse of this once-in-a-lifetime visitor, you will need a little help. 3I/ATLAS is far too faint to be seen with the naked eye or even standard binoculars; it requires the power of a large research-grade telescope to resolve.

Fortunately, the Virtual Telescope Project is stepping in to provide a front-row seat. Hosted by astrophysicist Gianluca Masi, a free livestream will begin at 11 p.m. EST on Thursday (0400 GMT on Friday). This broadcast represents one of our final opportunities to see the interstellar visitor as it zips past our planet.