{"id":438299,"date":"2026-05-12T18:21:12","date_gmt":"2026-05-12T18:21:12","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/438299\/"},"modified":"2026-05-12T18:21:12","modified_gmt":"2026-05-12T18:21:12","slug":"old-space-junk-from-the-1960s-just-revealed-a-hidden-effect-of-the-sun-on-earths-orbit","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/438299\/","title":{"rendered":"Old Space Junk From the 1960s Just Revealed a Hidden Effect of the Sun on Earth\u2019s Orbit"},"content":{"rendered":"

Space debris orbiting Earth loses altitude more rapidly when the Sun becomes highly active, a study published in Frontiers in Astronomy and Space Sciences has found. Scientists observed that once solar activity reaches a certain intensity, atmospheric drag increases enough to accelerate the descent of debris in low Earth orbit.<\/p>\n

The research sheds light on a growing issue for satellite operators and space agencies as low Earth orbit becomes increasingly crowded with active spacecraft and abandoned objects. <\/p>\n

Low Earth orbit, commonly called LEO, is used by Earth-observation satellites, communications systems, and internet constellations such as Starlink. The region, located between about 400 and 2,000 kilometers above Earth, is also filled with debris from decades of launches and collisions. Old rocket stages, fragments from destroyed satellites, and inactive spacecraft continue orbiting the planet at high speed. Tracking these objects has become a major focus for scientists because even small fragments can damage operational satellites. <\/p>\n

The Sun\u2019s Cycles Directly Affect Orbital Decay<\/p>\n

The Sun alternates between quiet and active periods in an approximately 11-year cycle. During active phases, sunspots become more numerous and solar emissions intensify, including ultraviolet radiation and charged particles. Researchers explain that this increase in solar energy heats the thermosphere, the upper layer of Earth\u2019s atmosphere extending from around 100 to 1,000 kilometers in altitude. As temperatures rise, the thermosphere expands outward.<\/p>\n

\"OrbitalOrbital decay of space debris tracked alongside solar activity and atmospheric density changes from 1988 to 2024. Credit: Frontiers in Astronomy and Space Sciences<\/p>\n

That expansion increases atmospheric density at orbital altitudes used by many satellites <\/a>and debris objects<\/a>. Denser atmospheric conditions create stronger drag, slowing objects and causing them to descend more quickly toward Earth.<\/p>\n

\u201cHere we show that space debris around Earth loses altitude much faster when the Sun is more active,\u201d said Dr. Ayisha Ashruf<\/a> of the Vikram Sarabhai Space Centre in the paper<\/a>. She added that: \u201cFor the first time, we find that once solar activity passes a certain level, this loss of altitude happens noticeably more quickly.\u201d<\/p>\n

The study also refers to the most recent solar maximum in 2024, a period marked by elevated solar emissions. Those emissions were linked to stronger atmospheric drag on orbiting objects.<\/p>\n

Long-Forgotten Debris Reveals Evidence Scientists Had Never Seen Before<\/p>\n

To analyze the phenomenon, the researchers tracked 17 debris objects in low Earth orbit over a period covering 36 years and spanning solar cycles 22 through 24. The objects orbit Earth between 600 and 800 kilometers above the surface and complete an orbit every 90 to 120 minutes. None of them has yet reentered the atmosphere.<\/p>\n

\"HistogramHistogram comparing peak orbital decay rates of space debris across solar cycles 22, 23, and 24. Credit: Frontiers in Astronomy and Space Sciences<\/p>\n

Unlike active satellites, debris objects do not use propulsion systems to maintain their altitude. The research team noted that this makes them useful indicators for measuring natural orbital decay caused by atmospheric conditions alone. The team compared the orbital histories of these objects with long-term records collected by the German Research Centre for Geosciences<\/a>. The data included sunspot numbers and measurements of solar radio and extreme ultraviolet emissions.<\/p>\n

Researchers discovered what they describe as a \u201ctransition boundary.\u201d Once sunspot activity exceeded roughly two-thirds of its maximum intensity, orbital decay increased significantly.<\/p>\n

\u201cThis threshold doesn\u2019t seem to be tied to a fixed value of solar radiation,\u201d\u00a0 Dr. Ashruf explained. \u201cbut rather to how close the Sun is to its peak activity.\u201d The paper also suggests that stronger extreme ultraviolet emissions near solar maximum may contribute to the effect.<\/p>\n

Satellites May Need More Orbit Corrections<\/p>\n

The findings could have direct consequences for satellite operations in low Earth orbit. Satellites experience the same drag forces as debris objects, meaning periods of strong solar activity may require more frequent adjustments to maintain stable orbits.<\/p>\n

The journal Frontiers in Astronomy and Space Sciences notes that faster orbital decay affects both fuel consumption and mission duration. Satellites launched near solar maximum periods may need additional fuel reserves for orbit corrections.<\/p>\n

\u201cOur results imply that when solar activity passes certain levels, satellites \u2014 just like space junk \u2014 lose altitude faster so that more orbit corrections are required,\u201d adding that: \u201cWhat is most interesting is that all of this information comes from objects launched back in the 1960s. They are still contributing to science, serving as valuable tools for studying long-term effects of solar activity on the thermosphere.\u201d<\/p>\n

\"2727-day moving average of solar EUV flux measurements across multiple solar cycles from 1988 to 2024. Credit: Frontiers in Astronomy and Space Sciences<\/p>\n","protected":false},"excerpt":{"rendered":"Space debris orbiting Earth loses altitude more rapidly when the Sun becomes highly active, a study published in…\n","protected":false},"author":2,"featured_media":438300,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[85,46,141,145],"class_list":["post-438299","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-il","tag-israel","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/438299","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=438299"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/438299\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/438300"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=438299"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=438299"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=438299"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}