Meet Earth's New Quasi-moon and Comet Lemmon (C/2025 A6)

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Read news from the world of astronomy for the week of September 5, 2025.

This week in the world of astronomy, meet Earth's new quasi-moon and Comet Lemmon (C/2025 A6). Plus, take a deep dive into Mars's surprisingly solid core.

Jupiter-bound Probe Flies By Venus

The European spacecraft en route to Jupiter, named JUICE, completed its only flyby of the planet Venus on August 31st.

Meet 2025 PN7, Earth’s New Quasi-moon

Just discovered, it’s been orbiting the Sun alongside Earth for decades, and will continue to do so for decades more

Webb Telescope Finds Interstellar Comet Has Unexpected Composition

Observations with the James Webb Space Telescope have shown the new interstellar Comet 3I/ATLAS is surprisingly rich in carbon dioxide.

Mars Might Have a Surprisingly Large, Solid Core, Marsquakes Reveal

Marsquakes reveal a lumpy, viscous mantle and a large, solid inner core, with profound implications for Mars past, present, and future.

Observing Highlights

SMP_2025Vic_Aug30mo-LIGHT__FEATURED image

This Week's Sky at a Glance, September 5 – 14

The waxing gibbous Moon shines in the south-southeast this evening, on a line between Altair and Fomalhaut. Altair is the bright star three or four fists above the Moon and maybe somewhat to the right.

Sweet Prospects for Comet Lemmon (C/2025 A6)

A promising comet could reach naked-eye brightness next month. Here’s how to track it.

Why We Look Up: Simply Stargazing

Whether you end up catching a falling star or not, meteor shower vigils offer time with the stars.

September Podcast: Hello, Saturn!

September’s night sky features the iconic Summer Triangle, almost directly overhead at nightfall, and a newcomer to the evening sky: the planet Saturn.

Presented by: Celestron.

Stargazing at Durlston Astronomy Centre

Join the welcoming astronomers from the Wessex Astronomical Society for an observing session at their observatory located in Durlston Country Park.

Are you a school, middle school, high school, or university?

Unistellar’s smart telescopes are trusted by 100+ educational institutions in the US … our connected telescopes bring the cosmos into the classroom, with NASA and SETI as our partners, the science behind it is as real as it gets. We have program that’s right for your school. See it in action: Watch how Boise State University uses our telescopes weekly for classes and science nights on campus → Video link