This article is a second analysis step from the descriptive arXiv:2001.10952 preprint. This work is aimed to arise awareness to the scientific astronomical community about the negative impact of satellites' mega-constellations and put in place an approximated estimations about loss of scientific contents expected for ground based astronomical observations when about 50,000 satellites will be displaced in LEO orbit. The first analysis regards the impact on professional astronomical images in optical windows. Then the study is expanded to other wavelengths and astronomical ground based facilities (radio and higher energies) to better understand which kind of effects are expected. Authors also try to perform a quantitative economic estimation related to the loss of value for public finances committed to the ground based astronomical facilities armed by satellites' constellations. These evaluations are intended for general purposes, can be improved and better estimated, but in this first phase they could be useful as evidentiary material to quantify the damage in subsequent legal actions against further satellites deployments.
The effect of satellite constellations on observations in the visible and IR domains is estimated, considering 18 constellations in development by SpaceX, Amazon, OneWeb, and others, with over 26,000 satellites, constituting a representative distribution. This study uses a series of simplifications and assumptions to obtain conservative, order-of-magnitude estimates of the effects. The number of illuminated satellites from the constellations above the horizon ranges from ~1600 right after sunset, decreasing to 1100 at the end of astronomical twilight, most of them (~85%) close to the horizon (…
The impact of large-scale constellations of satellites, is a concern for ground-based astronomers. In recent years there has been a significant increase in the number of satellites in Low-Earth Orbit and this trend is set to continue. The large number of satellites increases the probability that one will enter the field of view of a ground-based telescope at the right solar angle to appear bright enough that it can corrupt delicate measurements. We present a new tool Astrosat that will project satellite orbits onto the RA/DEC coordinate system for a given observer location and time and field o…
Measuring photometric brightness is a common tool for characterizaing satellites. However, characterizing satellite mega-constellations and their impact on astronomy research requires a new approach and methodology. A few measurements of singular satellites are not sufficient to fully describe a mega-constellation and assess its impact on modern astronomical systems. Characterizing the brightness of a satellite mega-constellation requires a comprehensive measurement program conducting numerous observations over the entire set of critical variables. Utilizing Pomenis, a small-aperture and wide …
Current optical space telescopes rely upon silicon Charge Coupled Devices (CCDs) to detect and image the incoming photons. The performance of a CCD detector depends on its ability to transfer electrons through the silicon efficiently, so that the signal from every pixel may be read out through a single amplifier. This process of electron transfer is highly susceptible to the effects of solar proton damage (or non-ionizing radiation damage). This is because charged particles passing through the CCD displace silicon atoms, introducing energy levels into the semi-conductor bandgap which act as lo…
The number of satellites in low-Earth orbit is increasing rapidly, and many tens of thousands of them are expected to be launched in the coming years. There is a strong concern among the astronomical community about the contamination of optical and near-infrared observations by satellite trails. We analyze the impact analysis of such constellations on optical and near-infrared astronomical observations in a rigorous and quantitative way, using updated constellation information, and considering imagers and spectrographs and their very different characteristics. We introduce an analytical method…
As the European maritime powers expanded their reach beyond north Atlantic coastal waters to distant lands as far away as the East Indies, access to a practical means of maritime navigation in the southern hemisphere became imperative. The first few voyages undertaken by the Dutch East India Company and its predecessor explicitly aimed at compiling star charts and constellations that were only visible south of the Equator, as practical navigation aids. The oldest known star atlas of southern constellations was published in 1603 by Frederick de Houtman. Controversies have plagued de Houtman's a…
Analysis of Laser-Satellite Deconfliction for Astronomical Observatories
Institute for Astronomy, University of Hawaii at Manoa（夏威夷大学马诺阿分校天文研究所）；California Institute of Technology（加州理工学院）；Subaru Telescope, National Astronomical Observatory of Japan（日本国立天文台昴星团望远镜）；W. M. Keck Observatory（W.M.凯克天文台）
Impact of Satellite Constellations on Observations with the 80-cm Telescope and the Mini-SiTian at the Xinglong Observatory, NAOC
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文学院）
Observations have been carried out in order to assess the optical characteristics of the BlueWalker 3 spacecraft which is the prototype for a new satellite constellation. The illumination phase function has been determined and evaluated. The average visual magnitude when seen overhead at the beginning or ending of astronomical twilight is found to be +1.4.
Due to ionosphere absorption and the interference by natural and artificial radio emissions, ground observation of the sky at the decameter or longer is very difficult. This unexplored part of electromagnetic spectrum has the potential of great discoveries, notably in the study of cosmic dark ages and dawn, but also in heliophysics and space weather, planets, cosmic ray and neutrinos, pulsar and interstellar medium, extragalactic radio sources, and even SETI. At a forum organized by the International Space Science Institute-Beijing (ISSI-BJ), we discussed the prospect of opening up this window…
There is a growing concern about an impact of low-Earth-orbit (LEO) satellite constellations on ground-based astronomical observations, in particular, on wide-field surveys in the optical and infrared. The Zwicky Transient Facility (ZTF), thanks to the large field of view of its camera, provides an ideal setup to study the effects of LEO megaconstellations - such as SpaceX's Starlink - on astronomical surveys. Here, we analyze the archival ZTF observations collected between 2019 November and 2021 September and find 5301 satellite streaks that can be attributed to Starlink satellites. We find t…
Starlink is a low-Earth orbit (LEO) satellite constellation operated by Space Exploration Technologies Corp. (SpaceX) which aims to provide global satellite internet access. Thus far, most photometric observations of Starlink satellites have primarily been from citizen scientists' visual observations without using quantitative detectors. This paper aims to characterize Starlink satellites and investigate the impact of mega constellations on ground-based astronomy, considering both the observed magnitude and two-line element (TLE) residuals. We collected 353 observations of 61 different Starlin…
The Impact of Artificial Space Objects on Optical Astronomy as Determined from 32 Million Photometric Observations
IAU Centre for the Protection of the Dark and Quiet Sky（国际天文联合会保护黑暗与宁静天空中心）；Czech Academy of Sciences（捷克科学院）；Institute of Physics, Czech Academy of Sciences（捷克科学院物理研究所）
SpaceTrack-TimeSeries: Time Series Dataset towards Satellite Orbit Analysis
Shanghai Satellite Network Research Institute Co., Ltd.（上海卫星网络研究所有限公司）；State Key Laboratory of Satellite Network（卫星网络国家重点实验室）；Shanghai Key Laboratory of Satellite Network（上海卫星网络重点实验室）
Measure the Sloan g' magnitudes of the Starlink's STARLINK-1130 (Darksat) and 1113 LEO communication satellites and determine the effectiveness of the Darksat darkening treatment at 475.4\,nm. Two observations of the Starlink's Darksat LEO communication satellite were conducted on 2020/02/08 and 2020/03/06 using a Sloan r' and g' filter respectively. While a second satellite, STARLINK-1113 was observed on 2020/03/06 using a Sloan g' filter. The initial observation on 2020/02/08 was a test observation when Darksat was still manoeuvring to its nominal orbit and orientation. Based on the successf…
SPHEREx confirms predictions for artificial satellite trail pollution in Low Earth Orbit
NASA Ames Research Center（美国国家航空航天局艾姆斯研究中心）；Bay Area Environmental Research Institute（湾区环境研究所）；IAU Centre for the Protection of the Dark and Quiet Sky（国际天文学联合会暗弱天空保护中心）；Centre de recherche sur les Ions, les Matériaux et la Photonique Université Caen Normandie, ENSICAEN, CNRS, CEA, Normandie Univ, CIMAP UMR6252（卡昂诺曼底大学离子、材料与光子研究中心）；Space Research Centre, Durham University（杜伦大学太空研究中心）；Planet4589 Research（Planet4589 研究）
Multi-conjugate adaptive optics (MCAO) will assist a new era of ground-based astronomical observations with the extremely large telescopes and the Very Large Telescope. High precision relative astrometry is among the main science drivers of these systems and challenging requirements have been set for the astrometric measurements. A clear understanding of the astrometric error budget is needed and the impact of the MCAO correction has to be taken into account. In this context, we propose an analytical formulation to estimate the residual phase produced by an MCAO correction in any direction of …
Large constellations of orbiting communication satellites will become an important source of noise for present and future astronomical observatories. Mitigation measures rely on high quality predictive models of the position and expected brightness of these objects. Optical linear imaging polarimetry holds promise as a quantitative tool to improve our understanding of the physics of reflection of sunlight off satellite components and through which models of expected brightness can be improved. We present the first simultaneous short-timescale linear polarimetry and optical photometry observati…
Long-duration gamma-ray burst (GRB) afterglow observations offer cutting-edge opportunities to characterise the star formation history of the Universe back to the epoch of reionisation, and to measure the chemical composition of interstellar and intergalactic gas through absorption spectroscopy. The main barrier to progress is the low efficiency in rapidly and confidently identifying which bursts are high redshift ($z > 5$) candidates before they fade, as this requires low-latency follow-up observations at near-infrared wavelengths (or longer) to determine a reliable photometric redshift estim…
