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, which was discovered in January and stayed in the news for a good nine months. The images of Lemmon's long and beautiful tail, created by the comet's solar heating, stopped me every time.

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

As a cosmologist who knows that she is not an expert on comets, I believe all the experts who, without a doubt, say that Comet 3I/Atlas is not an alien object. This shouldn't be disappointing. The comet remains interesting from a scientific point of view. It is different from Lemmon and SWAN because it has origins outside of our solar system. Comet 3I/Atlas is by definition interstellar.

Its arrival in our solar system presents us with an exciting opportunity. By studying its composition, we can learn a lot about its parent star, although it is impossible to reconstruct its exact trajectory. In other words, we can figure out the composition of a mystery star even if we don't know which star we're studying.

Our journey with comets this year is just the latest in a long chain of human reactions to the appearance of mysterious celestial objects 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 thinking for a moment that the 2025 comets were trying to tell us something.

Looking back on the past year, we see so many scary and disappointing events that it is easy to think that these comets could herald the end of the world as we know it. American science is in a quandary because current administration cancels grants and programs (see page 20). In both the US and UK, attacks on immigrants have become more widespread.

For me, as a Black and Jewish queer scholar and child of immigrants, maintaining courage is a daily challenge. I know there are people who want me to shut up. Despite all my scientific training, I might take comets as a sign that I should give up. But there is another option: as a scientist, I can witness how comets give me hope. They provide a beautiful visual sanctuary. The desire to see them also united people. I enjoy reading posts about them in my astrophotography groups. Although I find all the questions “Is this an alien?” The misinformation in various publications is deeply upsetting, I love that people are looking up.

In the future, in 2026, my wish list will be long. From a scientific perspective, I really want paradigm-changing observations of dark matter. Socially, I want all children to have the food, housing, education and health care they need in identity-affirming communities. These are big dreams that probably won't come true by the end of the year. But comets are a reminder that the universe is full of big and wonderful surprises. Just as we search for comets, we must also build the better world we need.