Carnegie Science

Happy birthday to the "Mother of Dark Matter," Vera Rubin, born on this day in 1928.

In our Solar System, the farther out you go, the slower you orbit—Mercury moves about 47 kilometers per second, Neptune about 5. Astronomers expected galaxies to work the same way, with stars slowing down toward the edges.

Working at Carnegie Science in the 1960s, Rubin and Kent Ford measured how fast stars orbit in the Andromeda galaxy and found something else entirely. Stars near the center were moving at roughly 250 kilometers per second—and stars tens of thousands of light-years farther out were still moving at roughly 250 kilometers per second. The curve went flat instead of falling.

The only explanation was mass astronomers couldn't see, far more of it than the visible galaxy accounted for. Rubin went on to find the same flat curve in dozens of other galaxies.

The galaxy in our special birthday logo is based on Andromeda, where she first observed the phenomenon.

Learn more about Vera Rubin and the case for dark matter: bit.ly/3Thw4DZ

Happy birthday to Robert S. Woodward, Carnegie's second president and the man historians have called "the first modern manager of science." His portrait is Object 18 in our series.

When Woodward took office in 1904, no one had settled a basic question: what should a research institution actually be? Andrew Carnegie had supplied the money and the mission but left the blueprint blank. Woodward spent 16 years drawing it—trading scattered grants for long-term support of proven investigators (among them future Nobel laureate Thomas Hunt Morgan) and building up Carnegie's own departments into what he called "a university in which there are no students."

The results spoke for themselves. Impressed by the institution's growth, Andrew Carnegie doubled his endowment, adding $2 million in 1907 and $10 million in 1911. The philosophy Woodward set—proven investigators and mission-driven departments over scattered grants—still guides Carnegie Science today.

Learn more: bit.ly/4yDEeXu

We've got another cool find from our archives! 🔭

Before we could build telescopes, someone had to find the mountain! By the early 1960s, Carnegie Science was already a force in astronomy through Mount Wilson—but being in the north meant the southern skies were out of reach. So the institution went looking for a mountain in the Southern Hemisphere: somewhere remote, high, and dry enough to see clearly to the edge of what telescopes could reach.

The search took most of the decade. In 1966, astronomers landed on a promising peak in the Chilean Andes, above the high Atacama Desert: Las Campanas. Over the next two years, the site kept proving itself, with some of the clearest, driest, darkest skies on Earth.

These field photographs come from one of the last scouting trips, in November 1968. They show the Carnegie Southern Observatory team—project supervisor Donald Buck and administrator Bruce Adkison among them—walking the ridgelines and checking the water supplies, judging whether we could sustain an observatory all the way up there.

Spoiler: it definitely could. Days later, Observatories Director Horace Babcock met with Chilean President Eduardo Frei to secure the land, and Carnegie finalized the purchase of 50,000 acres in July 1969. The first telescope—Swope—rose by 1971.

And we haven't stopped. The du Pont telescope followed in 1977, the twin Magellan telescopes on Manqui peak in 2000 and 2002, the Local Volume Mapper in 2023, and the Giant Magellan Telescope, which is underway now.

These photos are Object 17 in our series. Read the full story 👇
bit.ly/44EpSsc

On July 20, 1969, Apollo 11 landed on the Moon and the samples the crew carried home have been changing how we understand our Moon and Solar System for decades. They showed us that planets are born hot and violent, that the Moon's dark basins are impact scars rather than ancient seas, and —thanks to work by the late Carnegie geochemist Erik Hauri—that the Moon isn't the bone-dry world we long assumed.

Fifty-seven years later, Carnegie scientists are still finding new answers in those rocks. 🌑 Here are three things we learned from Apollo: bit.ly/4fIv3xk

📢 Astronomers just found the first atmosphere on a rocky planet in its star's habitable zone!

LHS 1140 b sits about 49 light-years away, a super-Earth roughly 5.6 times Earth's mass, circling its red dwarf star every 24.7 days. Rather than hunt for the faint signatures of water or carbon dioxide (too subtle to catch on planets this small, even for telescopes like NASA's James Webb Space Telescope) a team led by Harvard University's Collin Cherubim and including Carnegie Science astronomer Shreyas Vissapragada went looking for signs of helium escaping the atmosphere instead.

In 2024, using the WINERED spectrograph on the Magellan Clay telescope at Carnegie's Las Campanas Observatory in Chile, they found it! Interestingly, the signal was missing on return observations in 2025.

"It is a rare privilege to witness the atmosphere of an extrasolar planet change on such short, human timescales!" said Vissapragada.

The team reads the results as evidence of a layered atmosphere with helium in the upper atmosphere and heavier molecules like water tucked closer to the surface.

Meanwhile the system's other planet, LHS 1140 c, whips around the same star every 3.78 days and shows no atmosphere at all. The two may sit on opposite sides of what astronomers call the "cosmic shoreline": the divide between worlds that keep their air and worlds that lose it.

Carnegie's Johanna Teske, Nicole Wallack, William Misener and Andrew McWilliam also contributed to the work, published this week in Science.

Read the full press release: bit.ly/4vFSooi

Science moves fast. So does this Pop-Up Store. 🏃⚡

Our first seasonal swag collection just dropped, and once August 3 hits, it's gone—no reruns, no "just checking if it's still up," nothing. Orders will be produced and shipped after the store closes, and then it's back to the lab until the next seasonal drop.

To be clear: this isn't a fundraiser—it's just really good merch! Time to translate your love of Carnegie Science into your summer wardrobe.

🛒 Shop here: https://cspopupstore.itemorder.com/shop/home/

We made the cover of Nature Astronomy! 🌌

Research by a team including Carnegie astronomer Jeff Rich appears on the journal’s June 2026 cover, highlighting a new way to uncover the histories of galaxies beyond our own Milky Way.

Led by Lisa J. Kewley of the Center for Astrophysics l Harvard & Smithsonian, the team studied chemical fingerprints across NGC 1365, also known as the Great Barred Spiral Galaxy. By mapping oxygen throughout the galaxy and comparing the results with cosmological simulations, the astronomers reconstructed how NGC 1365 grew and merged with smaller galaxies over 12 billion years.

The researchers call this new approach “extragalactic archeology.”

The study was made possible by data from the Carnegie-led TYPHOON survey, collected with the du Pont telescope at Carnegie Science’s Las Campanas Observatory in Chile.

Congratulations to the entire team, especially study co-author Alex Garcia of the University of Virginia, whose high-resolution galaxy image appears on the cover!

Learn more: bit.ly/4bmm966

Cover image: Alex Garcia, University of Virginia

For more than five decades, Carnegie Science’s Las Campanas Observatory has explored the universe from beneath some of the clearest skies on Earth. But its impact reaches far beyond the telescopes.

Through educational visits, teacher workshops, science festivals, accessible resources, digital programming, and the LabMóvil Conciencia Astronomía, LCO connects students, families, educators, and communities throughout Chile with astronomy and scientific discovery.

The observatory’s outreach work also emphasizes the protection of dark skies, expands access to science for people with disabilities, and introduces young people to the many careers that make astronomical research possible.

In our latest feature, LCO Communications and Outreach Officer Carol Rojas explains how she and her colleagues are making science more open, approachable, and connected to people.

Read “Beyond the Telescopes: Science in Service of People”: https://carnegiescience.edu/beyond-telescopes-science-service-people?utm_source=instagram&utm_medium=social&utm_campaign=outreach&utm_content=link-carol-rojas-science-in-service

🌟 Please join us in welcoming the CASSI Class of 2026 to Carnegie Science!

These 16 undergraduate students from colleges and universities across California will join us in Pasadena for 10 weeks of paid, hands-on astronomical research and professional development.

Working alongside astronomers and engineers at the Carnegie Science Observatories, the students will study escaping exoplanet atmospheres, black holes, stellar evolution, galaxy growth, gravitational waves, and more. Some will also help develop the instruments and technology that will power the next generation of astronomical discoveries. 🔭✨

Meet the interns and learn more about their summer research projects: https://bit.ly/4aIBcH5

🗞️ Extra, extra! Our special outreach and education edition has landed in inboxes.

From “trash-canoes” and tree walks to planetariums, observatory outreach, and summer internships, Carnegie Science is finding new ways to connect curious people of all ages with discovery.

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