Fresh images of a mysterious interstellar comet, which appears to pulse with a regular 'heartbeat', have been published by space agencies ahead of its closest approach to Earth. The comet, known as 3I/ATLAS, continues to intrigue astronomers and spark debate about its true nature.
The Cosmic Visitor with a 'Heartbeat'
NASA and the European Space Agency (ESA) have both released new imagery of the comet, which is due to make its nearest pass by our planet on December 19. The Hubble Space Telescope captured the object on November 30, when it was approximately 178 million miles from Earth. The image depicts the comet as a bright white speck, its glow caused by sunlight reflecting off a vast cloud of gas and dust, known as a coma.
Adding to the data, the ESA's Jupiter Icy Moons Explorer (Juice) orbiter took a photograph from a much closer distance of just 41 million miles on November 2. This sharper view not only shows the glowing coma but also hints at the presence of two distinct tails. ESA scientists note a visible 'plasma tail' of charged gas stretching upwards, and a fainter 'dust tail' of solid particles extending to the lower left.
Alien Craft or Icy Snowball? The Scientist Split
The comet's claim to fame is its strange, rhythmic brightening, which occurs like clockwork every 16.16 hours. This phenomenon has been likened to a celestial heartbeat. Harvard astrophysicist Dr Avi Loeb suggested last week that these periodic jets could be evidence of an alien spacecraft manoeuvring through our solar system. While acknowledging natural causes are possible, he posited the pattern might indicate deliberate movement.
However, this extraterrestrial theory has been met with considerable scepticism from other experts. Dr Matthew Genge, a specialist in cosmic dust at Imperial College London, told Metro that such periodic brightening is "nothing particularly unusual" for comets. "If it's a heartbeat, then those aliens are really, really, super chill, because that's incredibly slow," he quipped.
Dr Genge described the media frenzy as "ludicrous", asserting there is no compelling reason to believe 3I/ATLAS is anything more than a "dirty snowball" from deep space. The leading scientific explanation is that a volatile patch of ice on the comet's surface rotates into sunlight, heats up, and erupts in jets of gas and dust, causing the observed pulse.
A Rare Interstellar Guest
Regardless of the 'heartbeat' mystery, 3I/ATLAS remains a profoundly significant object. It is only the third interstellar visitor ever detected in our solar system, following 'Oumuamua in 2017. This suggests such objects may be more common than previously believed. Scientists estimate this comet could be billions of years older than our Sun, offering a pristine sample of material from another star system.
Dr Genge drew an analogy with waiting for a bus, noting that three such objects have now appeared in quick succession after none were seen for decades. "It does suggest more rocks are thrown out of other planetary systems than we previously assumed," he said.
The comet will make its closest approach to Earth on December 19, though it will remain a safe 170 million miles away—roughly twice the distance from the Earth to the Sun. It is then expected to swing past Jupiter, whose gravity may act as a slingshot, eventually ejecting it back into interstellar space. Astronomers will continue to track it until at least March 16 next year, when it moves beyond Jupiter's orbit and fades from view.
