LThe Tsuchinshan-ATLAS comet will pass closest to the Sun this weekend, marking a journey that began millions of years ago and promising a spectacular sight for Earth observers in October, provided it survives.
This small body of rock and ice was discovered in January 2023 by China’s Purple Mountain Observatory (Tsuchinshan), contributing to the first part of its name. The second part comes from the confirmation of its existence by a telescope from the South African ATLAS program.
REUTERS
Since its discovery, astronomers, who prefer more precise nomenclature, refer to it as C/2023 A3 as it continues its journey toward the Sun. The analysis of its trajectory is too brief, with “barely one year of hindsight,” to accurately determine the path it has traveled so far, explains Lucie Maquet, an astronomer at the Institute of Celestial Mechanics and Ephemeris Calculation (IMCCE) at the Paris-PSL Observatory.
The comet follows an “open orbit,” with models suggesting it may have originated up to 400,000 times the Earth-Sun distance before reaching our vicinity.
AFP
This comet has been on a journey spanning millions of years, likely formed in the Oort cloud—a hypothetical and vast collection of small celestial bodies at the edge of the solar system. Until now, viewing it with the naked eye was possible only from the Southern Hemisphere.
Soon Visible in the Northern Hemisphere
In the Northern Hemisphere, it will be visible starting October 13, when it will be closest to Earth at a distance of 71 million kilometers. If the weather permits, “it will be easily visible” each evening when looking “in the direction of the setting sun,” according to Ms. Maquet.
This is contingent on the comet surviving its close encounter with the Sun. As comets approach the Sun, the ice within their core sublimates, releasing a long tail of dust that reflects sunlight.
This characteristic tail, known as the coma, indicates that the object is undergoing “degassing.” The concern is whether this degassing will be excessive, risking the disintegration of the comet.
An unfortunate outcome “is always a possibility,” warns the astronomer, because the combination of ice and rocks “may not withstand the Sun’s gravitational forces.” The good news is that C/2023 A3 appears to have a very large core, increasing the likelihood of its survival during this passage.
Where Will It Go Next?
As for its future trajectory, that remains uncertain. Its solar journey will result in changes to its orbit, influenced by the gravity of stars it encounters and the mass loss experienced from its proximity to the Sun.
The models used suggest—though without certainty—that it may be “ejected from the solar system, lost among the stars,” according to the September IMCCE bulletin.
Ultimately, everything will depend on the encounters C/2023 A3 experiences during its journey through the Oort cloud, potentially thousands of years in the future. The astronomer notes that it could simply “pass close enough to another body in that region to be redirected back for another trip through the solar system.”
Lhe Tsuchinshan-ATLAS comet passes closest to the Sun this weekend, on a journey that began millions of years ago, which promises a remarkable spectacle for Earthlings in October if it survives.
The small body of rock and ice was detected in January 2023 by China’s Purple Mountain Observatory (Tsuchinshan), giving it the first half of its name. He owes the second to the confirmation of his existence by a telescope from the South African ATLAS program.
REUTERS
Since then, for astronomers, who prefer more rigorous nomenclatures, C/2023 A3 continues its journey towards the Sun. The study of its course is too short, with “barely one year of hindsight,” to know precisely the path it has followed until now, explains Lucie Maquet, astronomer at the Institute of Celestial Mechanics and of Ephemeris Calculation (IMCCE), located within the Paris-PSL Observatory.
It follows an orbit “which is not closed,” with models suggesting that it could have been up to 400,000 times the Earth-Sun distance before reaching us.
AFP
A journey counting in millions of years for this comet, which probably saw the light of day in the Oort cloud, a hypothetical and gigantic assembly of tiny planets and celestial bodies at the edge of the solar system. Until now, you had to be in the Southern Hemisphere to hope to see it with the naked eye.
Soon Visible in the Northern Hemisphere
In the Northern Hemisphere, it will be visible from October 13, when it will be closest to Earth at 71 million kilometers away. If the weather is suitable, it will be “obvious” every evening when looking “in the direction of the setting sun,” according to Ms. Maquet.
However, this visibility is contingent upon the comet surviving its passage near the Sun. When comets approach our star, the ice contained in their core sublimates and releases a long trail of dust that reflects solar light.
This characteristic hair, known as the coma, indicates that the comet is “degassing.” The question remains as to whether this degassing will not be too excessive, risking the disintegration of this unwary visitor.
A catastrophe is “always possible,” according to the astronomer, because the assembly of ice and stones “may very well not resist the force of gravity of the Sun.” The good news is that C/2023 A3 appears to have a very massive core, suggesting “there is a good chance that it will survive” its passage.
Where Will It Go Next?
As for its future course, it is unpredictable. Its solar odyssey will not be without consequences on its orbit, disrupted by the gravity of the celestial bodies it encounters and the weight loss incurred from the Sun.
The models predict, though without commitment, that it could be “ejected from the solar system, getting lost between the stars,” according to the September IMCCE bulletin.
Everything will ultimately depend on the encounters that C/2023 A3 will make during its journey through the Oort cloud, a few thousand years from now. It would take just one “deflecting” celestial body to steer it back into the solar system for another trip.
What to Expect When Viewing the Comet
For those eager to catch a glimpse of the comet when it becomes visible in the Northern Hemisphere, here are some practical tips:
- Timing: Plan your viewing for evenings around October 13 when visibility is optimal.
- Location: Find a dark area away from city lights to enhance visibility.
- Equipment: Binoculars or a telescope can provide a better view, but the comet may also be visible to the naked eye.
- Weather: Check local weather conditions to ensure clear skies.
Creating a Viewing Party
Why not gather friends and family for a celestial viewing party? Here are a few ideas to make it special:
- Snacks: Prepare space-themed snacks and beverages.
- Astrophysics Talk: Dive into discussions about comets, asteroids, and space exploration.
- Photography: Equip yourself with cameras to capture those precious moments.
Fascinating Facts About Comets
- Age: Comets are among the oldest celestial bodies in the solar system.
- Made of Ice and Rock: They are primarily composed of ice, dust, and rocky materials.
- Oort Cloud: The Oort cloud is a distant sphere of icy bodies surrounding our solar system.
- Short vs. Long Period: Short-period comets orbit within the inner solar system, while long-period comets, like C/2023 A3, originate from the Oort cloud.
Comets and Their Influence on Earth
Throughout history, comets have influenced human civilization. Often seen as omens or carriers of significant change, their appearance has inspired myths and speculation. Understanding comets like C/2023 A3 can not only enhance our appreciation of the cosmos but also promote scientific inquiry into our solar system’s origins and workings.
