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Are there telescopes monitoring space objects 24 hrs a day
Executive summary
There is no single telescope that watches every object in space 24/7, but coordinated networks of ground and space sensors provide near-continuous monitoring for specific classes of objects: solar observatories run 24/7, and space‑surveillance networks of radars and telescopes operate worldwide to track satellites and debris on an ongoing basis (NSF network; US SSN) [1] [2]. Ground optical systems are limited by night, weather and geometry, so round‑the‑clock coverage is achieved by a mix of geographically distributed optical telescopes, radars, and satellites rather than one always‑on instrument [2] [3].
1. No single telescope sees everything all the time — networks do
Individual telescopes — whether ground optical, radar, or space telescopes — have operational limits: optical telescopes cannot see through daylight or clouds and space telescopes have fixed pointing and mission priorities; instead, continuous monitoring is achieved by networks. The U.S. Space Surveillance Network combines 30+ ground radars and optical telescopes plus satellites to detect, track and catalogue objects in orbit, providing ongoing operations rather than one instrument watching 24/7 [2]. NASA/AFRL observatories like MCAT on Ascension Island run fast‑tracking, automated optical systems to survey specific regimes (GEO, LEO) but still form part of a distributed effort [4].
2. Some systems are explicitly designed for 24/7 observation — mainly the Sun
There are purpose-built worldwide networks that observe the Sun continuously; the National Science Foundation documents a six‑telescope global network designed to observe the Sun 24/7 for space‑weather prediction [1]. Those are special cases: the Sun is bright and requires continuous monitoring for near‑term impacts on Earth, so dedicated, identical stations at different longitudes provide true around‑the‑clock coverage [1].
3. Ground optical telescopes face day/night and weather limits
Optical telescopes used for space situational awareness (SSA) — whether national assets like GEODSS or research observatories used for debris surveys — are constrained by darkness and local weather. GEODSS-type optical systems operate at night and depend on clear skies; clouds and daytime sky brightness limit their utility, so continuous global coverage requires many geographically dispersed sites [2] [3].
4. Radars complement optical systems for continuous LEO monitoring
Radars are a crucial complement because they can operate day and night and through clouds, making them well suited for low‑Earth orbit (LEO) object tracking. ESA and other agencies note that radars are advantageous for LEO observations while telescopes are better for GEO and higher altitudes; that division of labor is why the SSN combines both sensor types [3] [2].
5. Space telescopes and dedicated sensors add persistent capability but are not universal watchers
Space‑based observatories (Hubble, Chandra, Webb, etc.) conduct targeted science observations on schedules and are not surveilling Earth orbit continuously [5] [6]. The Space Surveillance Telescope (SST) is a dedicated asset for detecting and cataloguing satellites, near‑Earth objects and debris and entered operational capability recently — it greatly improves deep‑space surveillance but is one node in a wider network rather than a single 24/7 monitor [7] [8].
6. Sensitivity and catalog limits — “continuous” doesn’t equal “complete”
Even with persistent monitoring by networks, catalogs focus on larger objects: ESA explains that typical catalog thresholds are ~10 cm in LEO and 0.3–1 m in GEO, meaning many smaller fragments remain below routine detection limits despite ongoing surveillance [3]. Ground telescopes can be very sensitive (detecting faint GEO debris down to magnitudes +19–+21 in campaign mode) yet still miss subcatalogue debris that networks infer only statistically [3].
7. Automation and distributed small telescope concepts aim to scale coverage
Research and operational groups are exploring scalable networks of smaller, automated telescopes (with fast tracking and EMCCD imagers) to broaden coverage and relieve the burden on large, resource‑intensive instruments. PNNL and university programs have evaluated distributed, small observing stations as a path to more continuous, wider surveillance capability [9] [10].
8. Takeaway and practical meaning for the question “24 hrs a day”
If you mean “is there one telescope watching all space objects non‑stop?” — not according to the available reporting; instead, continuous awareness is achieved by a mosaic of radars, optical telescopes, space sensors and global station networks, with gaps in sensitivity and coverage for very small debris [2] [3] [1]. For the Sun, dedicated six‑station networks do provide genuine 24/7 monitoring [1].
Limitations: reporting cited here describes system roles and limits but does not provide a minute‑by‑minute operational log showing literal 24/7 tracking of every catalogued object; available sources do not mention a single instrument performing that role alone [2] [3].