The interstellar object dubbed 3I/ATLAS has been fascinating astronomers since its discovery in early July.
The object, generally believed to be a comet, is screaming through the solar system at around 137,000 mph, and is expected to make a close pass of Mars as soon as next week.
And it recently met some considerable resistance as well during its unusual visit. Earlier this week, the Sun unleashed a ferocious flurry of plasma and magnetic fields, called a coronal mass ejection, straight at 3I/ATLAS.
It’s a fascinating and exceedingly rare collision, as SpaceWeather.com reports, the result of which remains speculative.
Astronomers have previously observed comets originating from within the solar system colliding with the Sun’s plasma. For instance, in April 2007, NASA’s STEREO A spacecraft watched as a comet dubbed Encke temporarily lost its tail after being hit by a “wave of solar material.”
“The effect, however, was only temporary — within minutes a new tail formed,” NASA explained in a 2015 blog post.
3I/ATLAS has repeatedly caught researchers off guard. For instance, observations found that it features a much higher ratio of carbon dioxide to water than expected. Harvard astrophysicist Avi Loeb has also pondered its strange trajectory, which takes it suspiciously close to Jupiter, Mars, and Venus.
Next week, it’s expected to come within just 1.67 million miles of Mars, in what Loeb called a “remarkable fine-tuning of its path.” (Loeb has raised the possibility that the object is some form of extraterrestrial technology, though NASA has pushed back on that idea.)
The astronomer has also suggested that the object could be far more massive than the previous two known interstellar objects, concluding in a recent blog post that its mass “must be bigger than 33 billion tons,” and measuring at least 3.1 miles across. The prior objects, ‘Oumuamua and 2I/Borisov, measured roughly a quarter mile and 0.6 miles in length, respectively.
Earlier this month, astronomers observed 3I/ATLAS becoming extremely bright as it approached its perihelion, or the closest point to the Sun, as it was being exposed to far more solar radiation.
Most of that brightness increase has been in the green part of the visible light spectrum, suggesting a “surge of gas production as the comet nears the Sun,” according to SpaceWeather. “The key compound is diatomic carbon (C2), which glows emerald when energized by solar UV radiation.”
How it fared during this week’s coronal mass ejection remains unclear. Hopefully, scientists will catch a glimpse of 3I/ATLAS as it rips by Mars next week to find out.
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