Blue-green comet 3I/ATLAS to fly past Earth in time for Christmas
If you look up at the night sky in the week before Christmas you might see a mysterious green light – but it’s not Santa and his reindeers ahead of schedule. So what is it and why is it there?
READING LEVEL: ORANGE
A Christmas comet is coming to town – and we’re not talking about Santa’s famous reindeer.
The greenish-blue comet 3I/ATLAS has been forecast to fly by Earth this week, and hi-tech space telescopes and astronomers alike have already been scrambling to catch the incoming interstellar* visitor on camera.
Luckily, one amateur photographer has managed to snap a close-up — a gorgeous photo of the interstellar wonder glowing green over the Egyptian desert.
“From the heart of Egypt’s Black Desert, where volcanic hills rise like silent sentinels* and acacia trees stand alone against the night, an object from another star system drifts through our sky: interstellar comet 3I/ATLAS,” photographer Osama Fathi told the BBC.
The photo, which was snapped on the night of November 29, shows the comet streaking across the desert sky with trees in the foreground.
It shines a brilliant cyan* hue, which Fathi said was because of “faint cyanide* radical gas emission in its coma*,” which is the halo of gas and dust that forms around the solid nucleus* when the comet approaches the Sun.
However, the reason for the comet’s emerald tinge remains unclear. Experts previously believed its colour was caused by molecules of diatomic carbon* (C2) absorbing ultraviolet sunlight but researchers have found the object to be nearly completely devoid* of this gas, indicating that such a reaction could be the result of another chemical process.
Fathi said he was able to capture the stunning spectacle using an “astro-modified* Nikon Z6 camera, paired with a RedCat telescope lens.”
He reportedly zoomed in at just the right angle to isolate the comet against the desertscape using a special photographic technique to reveal the structure and halo of the comet.
The fact the photo was taken in an isolated area, far from any competing city lights, reportedly helped to enhance the photo’s clarity.
“In that still, beautiful scene, 3I/ATLAS appeared in the field of view: a faint visitor from another star system, crossing our sky once in a lifetime while the desert slept,” Fathi said.
Fathi was not the only one to capture the Christmas comet on film. On November 30, NASA’s Hubble Space Telescope captured a deeper look at interstellar comet 3I/ATLAS, with its Wide Field Camera 3 instrument as it rocketed through the solar system.
The cosmic photo showed ATLAS glowing blue while passing within 178 million miles of the planet.
Astronomers hope to get an even better view of the object when it makes its closest approach to our planet this Friday, December 19, during which it will pass within 170 million miles of Earth, before continuing on into the cosmos.
POLL
GLOSSARY
- interstellar: an object travelling through space that isn’t gravitationally bound to a star
- sentinels: soldiers standing guard
- cyan: a greenish blue colour
- cyanide: a poisonous gas
- coma: the surrounding atmosphere of the comet, made of gas and dust, that forms when the icy rock gets closer to the sun
- nucleus: the solid, central part of a comet, formed from rock, dust and frozen gases
- diatomic carbon: an inorganic chemical made of two carbon atoms connected by a multiple bond
- devoid: completely lacking something
- astro-modified: when the sensor of a DSLR camera has been altered to make it better for capturing certain types of light emitted from space that normal cameras can’t pick up
EXTRA READING
Eerie blue fireball lights the sky
Meteors puts on cosmic show
Rare green comet visible for first time in 437 years
QUICK QUIZ
1. Where was the recent amateur photo of 3I/ATLAS taken?
2. Who took the photo?
3. What colour is the comet?
4. What environmental factors helped to reveal the structure of the comet in the photo?
5. When will 3I/ATLAS make its closest approach to Earth?
LISTEN TO THIS STORY
CLASSROOM ACTIVITIES
1. Write about it
Write a description of, or a story about, a comet as it is shooting across the sky. Use as many descriptive words as you can to make your reader feel like they are right there with the comet.
Time: allow at least 15 minutes to complete this activity
Curriculum Links: English
2. Extension
What do you think causes comets? Brainstorm ideas. Then, use your research skills to check your ideas. Use all of the information to create an information poster that will help other kids understand how comets are formed and what happens to them.
Time: allow at least 60 minutes to complete this activity
Curriculum Links English, Science
VCOP ACTIVITY
Vivacious vocabulary
Find words in the text that you find high-level and highlight them in yellow.
They are not wow words yet because you might not understand what they mean. Some of the words you have highlighted might be in the glossary, but there are probably some extra ones that you need to investigate further.
Pick three of your highlighted words and let’s investigate.
Create a card template that you can use as a resource in your classroom.
At the top write one of your highlighted words. Underneath this, add a kid-friendly definition. That means you might need to first look up the word in the dictionary, then rewrite the definition to make more sense to kids.
Next you’ll need to come up with two new examples of sentences for your word to show how it can be used.
And finally, see if you can create two activities that you could do to investigate the word further.
Share with a classmate to see what word they chose. Can you complete each other’s activity?