Comets were on fire this year – for better or worse

I don’t think anyone has stated this, but 2025 was a big year for comets. There was Comet Lemmon, discovered in January and which made headlines for a good nine months. The images of Lemmon’s long, beautiful tail, created by the comet’s solar heating, stopped me every time.

Then there was the September discovery of C/2025 R2 (SWAN), a comet so bright that even when it was near the moon on Halloween, it was still clearly visible to observers. And there was Comet 3I/Atlas, which became famous because a Harvard University astronomer whose main area of ​​expertise is cosmology declared it to be an extraterrestrial probe.

As a cosmologist who knows she is not a comet expert, I believe all the experts who say that, without a doubt, Comet 3I/Atlas is not an extraterrestrial object. This shouldn’t be disappointing. The comet is still scientifically fascinating. It is different from Lemmon and SWAN because it has origins outside our solar system. Comet 3I/Atlas is, by definition, interstellar.

Its arrival in our solar system makes it an exciting opportunity. By studying its composition, we can learn a lot about its home star, although it is impossible to reverse engineer its exact trajectory. In other words, we can learn more about the composition of a mysterious star, even if we don’t know which star we are studying.

Our journey with comets this year is just the latest in a long line of human reactions to mysterious celestial objects appearing in the sky. Perhaps most famously, the passage of Halley’s Comet in 1066 was depicted in the Bayeux Tapestry as signaling the start of the Norman invasion of England. Today we know that humanity is not the center of the universe – and that the universe has no center – but I could forgive someone for momentarily thinking that the comets of 2025 are trying to tell us something.

When we look back on the year, so many scary and disappointing things have happened that it can be easy to think that these comets could have heralded the end of the world as we know it. American science is on the ropes as the current administration cancels grants and programs (see page 20). In both the United States and the United Kingdom, attacks on immigrants have become more common.

As a queer Black and Jewish scientist and child of immigrants, keeping heart is a daily challenge for me. I am aware that there are people who want me to shut up. For all my scientific training, I might choose to read comets as a sign that I should give in. But there is another option: I can witness, as a scientist, how comets bring hope to me. They make a beautiful visual sanctuary. The quest to see them also brought people together. I enjoy posts about them in my astrophotography groups. While I find all the “Is it an alien?” » misinformation in various publications is deeply frustrating, I like people to look up.

By 2026, my wish list is long. Scientifically, I really want a paradigm-changing observation of dark matter. Socially, I want all children to have access to the food, housing, education and medical care they need in communities that affirm their identity. These are big dreams that probably won’t come true by the end of the year. But comets remind us that the universe is full of big, wonderful surprises. Just as we do the work of finding comets, we must also build the better world we need.