{"id":42,"date":"2026-01-06T18:57:51","date_gmt":"2026-01-06T18:57:51","guid":{"rendered":"https:\/\/magazine.hmc.edu\/fall-winter-25-26\/?p=42"},"modified":"2026-01-07T17:57:00","modified_gmt":"2026-01-07T17:57:00","slug":"the-dynamic-sky","status":"publish","type":"post","link":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/the-dynamic-sky\/","title":{"rendered":"The Dynamic Sky"},"content":{"rendered":"\n

Meredith rawls \u201908 found her way to astrophysics through a process of elimination\u2014by ruling out chemistry, math, computer science, biology and engineering. Ironically, she says, she nearly failed her freshman physics course at Mudd. Nonetheless, she persisted, knowing she wanted a career in astronomy. <\/p>\n\n\n\n

Rawls is a research scientist at the University of Washington who has, since 2016, been working on the Vera C. Rubin Observatory. This new facility, located on a Chilean mountaintop and equipped with the largest digital camera ever built, went live in June 2025. Rubin will repeatedly scan the sky for 10 years and create an ultra-wide, ultra-high-definition time-lapse record of our universe. <\/p>\n\n\n\n

The Rubin Observatory aims to better understand dark matter, the solar system and the Milky Way, as well as explore \u201cobjects that change position or brightness over time.\u201d Rawls\u2019s work relates to the last goal, which she poetically calls the \u201cdynamic sky.\u201d The uniqueness of the Rubin Observatory, she explains, is that it will \u201csurvey the entire southern sky and build up a database of observations that are then available to the astronomical community to enable all kinds of amazing science.\u201d <\/p>\n\n\n\n

In June, the Rubin Observatory became fully operational, and released \u201cfirst look\u201d images on its website, which also includes videos and interactive tools like a Skyviewer and Orbitviewer. Along with the images, observatory staff released a data preview. Rawls says, \u201cPeople have been using the data to do all kinds of early science, like finding new supernovae and testing out their own scientific workflows separate from what we produce.\u201d The first official data release\u2014which will contain packages of data Rawls and her colleagues prepare for scientists\u2014won\u2019t happen until 2026. <\/p>\n\n\n\n

\"\"
At the Rubin Observatory in Chile, a Feb. 25, 2025 image of the night sky shows a launched Starlink train plus several fainter satellite streaks as well as more traditional terrestrial light
pollution in the distance. Photo credit: Alysha Shugart<\/figcaption><\/figure>\n\n\n\n

Soon, people worldwide will see the observatory\u2019s \u201calert streams,\u201d which detail minute changes in the night sky. Astronomers will thus be alerted to a change between images almost immediately. Rawls works to ensure the algorithms detecting these changes are robust, \u201cverifying and validating that the data products all of the different Rubin pipelines make are doing what we expect.\u201d Rawls predicts there will be around 10 million of these alerts (similar to social media posts) every night. While alerts won\u2019t include as much detailed information as full data releases because they are processed in real time, they will alert astronomers that the sky is changing in a certain area so follow-up observations can be made. <\/p>\n\n\n\n

Although Rawls\u2019s work with the Rubin Observatory is central to her role as a research scientist, she also works on other projects, including the impact of satellite constellations. \u201cThere are an increasingly large number of bright satellites being launched into low-Earth orbit\u2014things like SpaceX Starlink,\u201d she says. These satellites threaten to interfere with the work done by the Rubin Observatory because the telescope is so sensitive. \u201cI use the analogy like bugs on a windshield to explain this. You\u2019re trying to take a picture of some of these faint distant galaxies, and there\u2019s this bright reflective satellite that just comes across and leaves a streak in your image.\u201d <\/p>\n\n\n\n

Rawls spends a lot of time developing tools and techniques to mitigate this interference, including liaising with companies and other stakeholders who are concerned about this problem. Beyond the effects on astronomers, satellites change the night sky. If we continue to let large numbers of satellites just get launched into orbit with no regulation or limits, Rawls says, it will be harder for people to view the stars. \u201cYou\u2019re going to see more swarm-y moving things than you\u2019ll be able to see stars in the Milky Way,\u201d she says, noting that some of these objects appear even brighter than stars. This is a subject Rawls and several colleagues addressed in their 2022 Nature Astronomy article \u201cThe case for space environmentalism,\u201d which views the impact of ever-increasing satellite constellations as akin to the pollution of the atmosphere and ocean. \u201cIt\u2019s just a fundamental change that no one really consented to,\u201d Rawls says, and this has unknown consequences. When these satellites burn up in the atmosphere, they can leave debris behind, she adds. The companies that make them seem to be assuming, she says, \u201cthat the atmosphere can take an infinite amount of surprise metals burning up in it without any repercussions.\u201d <\/p>\n\n\n\n

\n

\u201cIf we continue to let large numbers of satellites just get launched into orbit with no regulation or limits, it will be harder for people to view the stars.\u201d<\/p>\nMEREDITH RAWLS \u201908<\/cite><\/blockquote>\n\n\n\n

This is a difficult problem to address because it\u2019s global in scope, Rawls says: \u201cNo one country can solve this independently.\u201d While she believes satellites can be used constructively, she notes that the lack of regulation, and the slowness of regulatory bodies in acting to mitigate their impact is a problem for both astronomers and the larger global community. <\/p>\n\n\n\n

This past August, Rawls participated in a gathering of experts to discuss the effects of satellite constellations, both on the Rubin Observatory and the wider sky and how to address them. The group\u2019s findings and recommendations were published in a recent report. She also co-leads an organization called SatHub at the IAU Center for the Protection of the Dark and Quiet Sky, which is open to both astronomers and other citizens who care about this issue. <\/p>\n\n\n\n

Rawls has been stargazing since her childhood in eastern Washington. Her Girl Scout Gold Award project was focused on reducing light pollution at a summer camp she regularly attended: She raised money to buy shields to put on the very bright streetlights near the camp in order to point the light toward the ground and make it easier to see the stars. \u201cI feel like it\u2019s a little bit full circle that now I actually work as an astronomer on a different, brand new light pollution,\u201d she says.<\/p>\n","protected":false},"excerpt":{"rendered":"

Meredith rawls \u201908 found her way to astrophysics through a process of elimination\u2014by ruling out chemistry, math, computer science, biology and engineering. Ironically, she says, she nearly failed her freshman physics course at Mudd. Nonetheless, she persisted, knowing she wanted a career in astronomy. Rawls is a research scientist at the University of Washington who […]<\/p>\n","protected":false},"author":1,"featured_media":84,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-42","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"acf":[],"_links":{"self":[{"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/posts\/42","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/comments?post=42"}],"version-history":[{"count":10,"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/posts\/42\/revisions"}],"predecessor-version":[{"id":120,"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/posts\/42\/revisions\/120"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/media\/84"}],"wp:attachment":[{"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/media?parent=42"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/categories?post=42"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/magazine.hmc.edu\/fall-winter-2025-2026\/wp-json\/wp\/v2\/tags?post=42"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}