Don’t stare at the Sun (unless you’re SOHO)

Space Snapshot

A newly-discovered comet zoomed into the headlines this week. Comet C/2025 R2 (SWAN) was discovered on Sept. 12 by the Solar Wind Anisotropies (SWAN) instrument on the Solar and Heliospheric Observatory (SOHO). The comet is currently most visible from the southern hemisphere, but northern hemisphere viewers may be able to see it very low to the western horizon around sunset. It is estimated to make its closest approach to Earth sometime around Oct. 12-19. Pictured: Comet C/2025 R2 (SWAN) imaged from Wellington, New Zealand. Image credit: Brian Diettrich.

Fact Worth Sharing

Although the Solar and Heliospheric Observatory was designed to study the Sun, it has done a phenomenal job spotting comets. Astronomers using the spacecraft have discovered over 5,000 comets since it launched in 1995.

Mission Briefings

Hayabusa2’s target asteroid is tinier and faster than expected. Recent observations of asteroid 1998 KY26 suggest it may be almost three times smaller and spinning much faster than previously thought. This could complicate landing conditions for Japan’s Hayabusa2 extended sample return mission, which is expected to reach the asteroid in 2031. Pictured: 1998 KY26 imaged by Japan’s Subaru Telescope in 2020. Image credit: National Astronomical Observatory of Japan.

The dwarf planet Quaoar is a miniature planetary system. Astronomers recently discovered a second moon orbiting the dwarf planet Quaoar, which orbits the Sun beyond Neptune. The tiny world is already known to have two rings and another moon.

Enticing material in Enceladus’ plumes may not come from its oceans after all. New research suggests that the organic molecules detected in the icy moon’s plumes could originate on its surface instead of in the oceans of liquid water hiding beneath its crust. “Although this doesn't rule out the possibility that Enceladus' ocean may be habitable, it does mean we need to be cautious in making that assumption just because of the composition of the plumes," study lead Grace Richards of Italy's National Institute for Astrophysics said in a statement.

NASA has barred Chinese nationals from working on its programs. This includes students and contractors with valid visas. The decision appears related to the Trump administration’s views on a “space race” with China.

From The Planetary Society

Comets are beautiful sights to behold, whether from Earth or up close. This week on Planetary Radio, host Sarah Al-Ahmed is joined by Mark McCaughrean, astronomer, science communicator, and former Senior Advisor for Science & Exploration at the European Space Agency, to talk about his new book, “111 Places in Space That You Must Not Miss.” Part of the popular “111 Places” travel series, the book transforms the guidebook format into a tour across the Solar System and beyond, from Apollo landing sites on the Moon to Europa’s hidden oceans, the afterglow of the Big Bang, and Comet 67P/Churyumov-Gerasimenko (pictured in an image from ESA’s Rosetta spacecraft). Image credit: ESA et al. 

Groundbreaking discoveries start with you! For over 45 years, members of The Planetary Society have teamed up to crowdfund science and technology projects that benefit space science and exploration. The STEP Grant Program — Science and Technology Empowered by the Public — was established to continue this tradition. And with your continued support, vital scientific research will be made possible. Please, join us in this crucial endeavor by making a gift today. Your support will fund the next round of STEP grant winners.

Space Advocacy Update

“Your advocacy is working.” This was Planetary Society Director of Government Relations Jack Kiraly’s message to protesters who gathered at NASA headquarters on Sept. 15 to rally against the proposed cuts to the agency. And indeed, within the last week, the House Appropriations Committee approved a 2026 budget that rejected the Trump administration’s proposal to cut NASA’s budget by 24.3 percent, instead funding the agency at about the same level as FY2025.

The 2025 fiscal year ends on Sept. 30, and it is unlikely that appropriations will be signed into law by that time, meaning the government will be funded under a stopgap spending authorization known as a continuing resolution. This is usually a temporary extension of current-year funding, but the White House technically has the power to control the rate of funding that flows to agencies. The Trump administration could therefore withhold funding so that NASA science would effectively feel the immediate consequences of the proposed 47% cut on its programs, making it impossible to continue operating its fleet of spacecraft. This could result in premature project terminations, ignoring the clear intent of Congress, which has acted to reject these proposals. You can learn more about this situation in a recording of a recent webinar from Planetary Society policy and advocacy leadership.

The co-chairs of the Planetary Science Caucus released a bipartisan letter today calling for explicit protections for NASA science programs in the upcoming continuing resolution. The Planetary Society has created a petition that U.S. residents can send to their representatives in Congress to echo this call.

Image credit: Space.com/Josh Dinner.

What's Up

In the predawn, look for super bright Venus in the east, joined by the crescent Moon on Sept. 19. Very bright Jupiter is above Venus. In the evening, look for yellowish Saturn. It is reaching opposition this week, meaning that it rises in the east around sunset and sets in the west around sunrise. Learn more in our guide to September’s night skies.

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Wow of the Week

As mentioned in the Fact Worth Sharing, the Solar and Heliospheric Observatory’s main job is studying the Sun. In doing so, it has captured some remarkable images like this one from 2015, which shows activity on the Sun’s surface alongside enormous coronal mass ejections shooting out in all directions. Also called SOHO, the spacecraft is credited with revolutionizing heliophysics, discovering phenomena including coronal waves, solar tsunamis, and sunquakes. Image credit: ESA/NASA/SOHO.

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